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  Current Issue
 
2021 Vol.41 Issue.4,Published 2021-04-20
Air Pollution Control
Water Pollution Control
Solid Waste
Soil Pollution Control
Environmental Microbiology
Environmental Ecology
Environmental Impact Assessment and Management
Environmental Toxicology and Health
Air Pollution Control
1489 Emission inventory of atmospheric pollutants replaced by “coal-to-electricity” policy in Beijing-Tianjin-Hebei region
LI Peng, WU Hua-cheng, ZHOU Wei-qing, ZHANG Zi-jian, WANG Mei-shun, ZHANG Ru-ting, LIU Song-tao, CHEN Chuan-min
A residential coal consumption estimation model was established based on artificial neural network, an emission inventory of air pollutants from the coal-to-electricity policy, a residential coal replacement program, in Beijing-Tianjin-Hebei (BTH) region was obtained. The results showed that there had been 2.59 million households that replaced coal with electricity in the BTH region by the end of 2018, which reduced about 7.07 million tons of residential coal, and reduced the emissions of PM2.5、NOx、SO2 by 28092, 7647 and 21743 tons respectively according to our model. Beijing and Tianjin had achieved more substantial effects and accounted for 62.01% and 22.82% of the total fuel source switch from coal to electricity in the BTH region. Based on the survey data, this study also established the monthly distribution coefficient of coal consumption in BTH cities, and found that the January consumption was largest, which accounted for 27%~40% of the total annual coal consumption.
2021 Vol. 41 (4): 1489-1497 [Abstract] ( 393 ) [HTML 1KB] [ PDF 2257KB] ( 971 )
1498 Research on ozone column concentration in Xinjiang based on OMI data
LIU Min-xia, SUN Rui-di, SONG Jia-ying, ZHANG Ya-ya, LI Bo-wen, YU Rui-xin, LI liang
Using Ozone Monitor (OMI) satellite inversion data, the atmospheric ozone column concentration data in Xinjiang from 2005 to 2018 were extracted and analyzed, and its temporal and spatial distribution pattern and influencing factors were discussed. The results showed that:In terms of time changes, in the past 14years, the atmospheric ozone column concentration in Xinjiang had shown a gradual upward trend. In spatial distribution, the concentration of ozone column gradually decreases from north to south, and the high value areas were concentrated in Altai, northern Tacheng and northern Changji. The low-value areas were concentrated in Hotan, Bayinguoleng Mongolia Autonomous Prefecture and most of the southern parts of Kashgar. In seasonal variation, the ozone column concentration in spring and summer was higher than that in autumn and winter, the high value area appeared alternately in spring and summer, and the winter was slightly higher than that in autumn, but the ozone column concentration in the four seasons showed a gradual upward trend. Stability analysis showed that the concentration of ozone column in the study area showed a distribution pattern of dispersion in the middle, south and north, and concentration in the east and west. Among the natural factors, climatic factors, wind field and altitude all showed significant positive correlation (P<0.01); Through backward trajectory tracking, it was found that the northwest and west air flows in the region were the most important transportation routes for ozone, and they accounted for the total airflow trajectories 78.59%, 57.29%. In human factors, the concentration of ozone column had a significant positive correlation with regional GDP, coal consumption, industrial waste gas emission and vehicle ownership (P<0.05). Among them, volatile organic compounds (VOCs) mainly comed from industrial sources, followed by traffic sources and residential sources. Generally speaking, the change of ozone concentration was affected by many factors, but air temperature, VOCs emission and absorbing aerosol were the dominant factors.
2021 Vol. 41 (4): 1498-1510 [Abstract] ( 291 ) [HTML 1KB] [ PDF 2089KB] ( 1182 )
1511 Mechanism of Qinghai-Tibet high pressure system on spring and summer ozone pollution over Sichuan-Chongqing area
LIU Wei, KANG Ping, ZHANG Xiao-ling, XIANG Wei-guo, LIU Zhi-hong, ZHANG Xu-tao, LI Chun-kai, SONG Rong-jin, LEI Yu
In order to study the mechanism of Qinghai-Tibet high pressure system on spring and summer ozone (O3) pollution over Sichuan-Chongqing area, the Micaps PLOT High upper-air total factor data, national environmental monitoring station O3 observation data and meteorological station data of 14 cities from April to September of 2015 to 2018 were analyzed. Results showed that O3 concentration was closely related to the distribution and quantity of the central position of Qinghai-Tibet high pressure system. The denser the high-pressure center, the more extreme areas and the number of centers, the higher the surface temperature and O3 concentration in the same period. Especially the frequency of the center appeared around 100°E and 28°N, the surface temperature was higher, led to the emergence of more extreme high concentration of O3. Compared and analyzing the influence of the north-south migration of the high-pressure ridge on O3 concentration during different years and months, it was found that the northward migration of high-pressure ridge leaded to longer sunshine duration and higher O3 concentration. The combined effects of high-pressure center and ridge line on O3 over Sichuan-Chongqing area were analyzed as well, which showed that high-pressure center and high-pressure ridge affect the O3 concentration mainly by controlling the surface temperature and sunshine duration, respectively. At the same time, the effect and degree of the two effects on O3 concentration were also different (i.e., sometimes the increase of O3 concentration showed synergistic effect, while sometimes antagonistic effect).
2021 Vol. 41 (4): 1511-1520 [Abstract] ( 307 ) [HTML 1KB] [ PDF 1375KB] ( 1037 )
1521 Dry deposition and fate of PCBs in a semi-arid and industrialized city, China
MAO Xiao-xuan, SONG Shi-jie, LI Zi-xuan, ZHANG Xiao-dong, GAO Hong, MA Jian-min, HUANG Tao, LI Chun-xin
A passive dry deposition sampler (PAS-DD) was used to monitor the atmospheric dry deposition fluxes and research the contamination characteristics of 18 polychlorinated biphenyls (PCBs) in Gaolan County, a semi-arid region of China, during the non-heating and heating seasons of 2018, and the sources and environmental fate of PCBs were analyzed and simulated using principle component analysis and multimedia environmental model. The PCBs dry deposition fluxes ranged from 13.0 to 158.8ng/(m2·d), and increased significantly during the heating season. Besides, the highest dry deposition flux was observed at the industrial estate. Tetra-PCBs and penta-PCBs were the dominant homologue groups, and the dry deposition fluxes of tetra-PCBs increased during the heating season. PCB-containing products, combustion and industrial thermal processes were considered to be the main PCBs emission sources. However, the unintentionally produced PCBs from combustion and industrial thermal processes may have a greater impact on the PCBs contamination in the study area. Soil was found to be the major PCB81 sink in the study area, and the transport of PCB81 from air to soil was the main environmental transport process; Atmospheric advection was a vital way of removing PCB81; Pollutant emission rate, advective flow residence time, and advective inflow concentration were important factors affecting the concentration of PCB81 in the atmosphere and soil.
2021 Vol. 41 (4): 1521-1529 [Abstract] ( 268 ) [HTML 1KB] [ PDF 812KB] ( 835 )
1530 Analysis of an episode of a black storm moving eastward from Xinjiang based on multi-source data and model simulation
HUANG Guan, GUO Zi-jia, ZHOU Ya-man, SU Xiao-lan, LIU Xin, CHEN Yong-hang, ZHOU Hai-jiang, YANG Lin-pei
Multi-Source monitoring data from satellite remote sensing, environmental monitoring and meteorological observation were comprehensively used to analyze the generation source, path and development process of a black storm in Xinjiang in April 2015 combining backward trajectory model. The results show that the pollutants at different heights during the black storm mainly from Xinjiang and its west of the Central Asia region along with the airflow, entered the northern Xinjiang accompanied by the southwest airflow almost at the same time, piled up along the Tianshan Mountains and then crossed the mountains into southern Xinjiang. Meanwhile, four typical cities (Urumqi, Hohhot, Lanzhou and Beijing) affected by the east transport of pollutants from the black storm were selected to analyze the influence of large amounts of dust aerosols on major meteorological parameters during the eastward transport of the black storm using regional climate model (RegCM4.6).The results show that the AOD for the four typical cities affected by the black storm's eastward transport during April 25~29 all increased, and the simulated pollution level was close to the actual. For the temperature response of the dusts at 2m near the surface, Beijing was the most visible, up to -1.68℃, while was not obvious at Urumqi, where the temperature near the ground during the dust episode decreased by 0.1℃ at the highest compared with that without dusts. When AOD reaches its maximum value, the temperature response of Hohhot and Lanzhou is -0.4℃ and -0.8℃ respectively. During the black strom episode, the maximum relative humidity response in Urumqi, Hohhot and Lanzhou was -3.3%, -7.3% and -4.7%, respectively, while the relative humidity in Beijing increased by about 10% compared with that without dusts when the AOD reached its maximum value on 29th.
2021 Vol. 41 (4): 1530-1539 [Abstract] ( 192 ) [HTML 1KB] [ PDF 4101KB] ( 769 )
1540 Numerical simulation of electret magnetic fiber in trapping charged Fe based fine particles
JIA Zhong-jian, DIAO Yong-fa, ZHANG Li-an, ZHOU Fa-shan, SHEN Heng-gen
In order to achieve ultra-low emission of Fe based fine particles in the production process of ferrous metallurgy and casting industry, this study proposed a method to improve sub-particle capturing by electret magnetic fibers. Based on CFD-DPM (Discrete Phase Model), the influence of charge distribution on fibers, particle pre-charge electric field intensity, fiber magnetic flux density and particle magnetic susceptibility on electret magnetic fiber capturing property was investigated. The results showed that:around the electret magnetic fiber, the magnetic force was more significantly affected by the distance than did the Coulomb force. The effect of magnetic force was limited within an extremely short distance around the fiber, and there was a linear relationship between the capturing efficiency and charge distribution on fibers and pre-charge electric field intensity. As for 0.5μm particle, the growth rate at which fiber carrying capacity and pre-charge electric field intensity increased the capturing efficiency was lower than that of 2.5μm article. When the particle size was between 0.5 and 1.0μm, enhancing the magnetic flux intensity of electret magnetic fiber and improving particle magnetic susceptibility were less effective in improving the capturing efficiency. When the particle size was between 1.5 and 2.5μm, enhancing the magnetic flux intensity of electret magnetic fiber and improving particle magnetic susceptibility could significantly improve the fiber capturing efficiency.
2021 Vol. 41 (4): 1540-1547 [Abstract] ( 238 ) [HTML 1KB] [ PDF 1065KB] ( 978 )
1548 Brownian aggregation in the process of submicron particles captured by single fiber
ZHANG Li-an, DIAO Yong-fa, CHU Ming-hao, WANG Ru-ge, SHEN Heng-gen
In view of the Brownian aggregation law in the process of submicron particles (0.1~0.5μm) captured by single fiber, the Brownian aggregation behavior in the process of the dust particles captured by single fiber was numerically studied based on computational fluid dynamics-population balance model (CFD-PBM), and the partition method was used to solve population balance equation (PBE). The effects of residence time, inlet particle diameter, airflow temperature, and Pe number on the Brownian aggregation were considered comprehensively, and the numerical simulation and experimental results were compared. The results showed that the Brownian aggregation kernel met the requirements of numerical simulation calculation. The Brownian aggregation of dust particles run through the entire process, aggregation effective time t=L/v (dimension length along with flow field direction/face velocity). The smaller the dust particles, the stronger the intensity of the Brownian motion, the smaller the number density gap between Bin-7 and Bin-0, and the particle diameter was negatively correlated with the Brownian aggregation intensity. Brownian aggregation was affected by airflow temperature by changing flow field dynamic viscosity and aggregation coefficient, which was positively correlated with the Brownian aggregation intensity, when T=300K, dp ≥ 0.5μm, the Brownian aggregation effect of particles can be ignored; Brownian aggregation was influenced by the change of Pe number through the change of diffusion coefficient, which was negatively correlated with the Brownian aggregation intensity.
2021 Vol. 41 (4): 1548-1554 [Abstract] ( 293 ) [HTML 1KB] [ PDF 773KB] ( 1576 )
1555 Dissolution kinetics of iron-containing particles: A review
TANG Yu-jing, JIA Xiao-hong, LI Rui, ZHANG Guo-hua, TANG Ming-jin
Aerosol deposition is one of the primary sources of soluble iron in the open ocean, having significant impacts on the oceanic primary productivity. However, large uncertainties in the deposition flux of soluble iron from aerosol particles still remain, due to the following reasons:1) iron solubility varies largely for aerosol particles from different sources; 2) chemical reaction during atmospheric transport would significantly affect iron solubility of aerosol particles. Laboratory studies of dissolution kinetics of iron-containing particles in aqueous solutions in the past 20 years have been reviewed in this paper, to assess the enhancement effects on iron solubility by atmospheric aqueous reactions. Dissolution kinetics of iron-containing particles have been summarized for proton-promoted dissolution, ligand-promoted dissolution and photoreductive dissolution mechanisms. In addition, pH, anion components and light radiation jointly determined the dissolution mechanisms of iron-containing particles; and iron speciation is the major factor which determines the potential solubility of iron. Lastly, an outlook for future research was also presented.
2021 Vol. 41 (4): 1555-1563 [Abstract] ( 246 ) [HTML 1KB] [ PDF 438KB] ( 1818 )
Water Pollution Control
1564 Screening of algal based on temperature and nutrient fluctuation tolerance and its community nitrogen and phosphorus removal rate
ZENG Jie, LIU Yu-ping, FENG Jie, ZHANG Qi-qi, QIAN Lei, LIU Jing
Aiming at screening out the dominant algae species which can adapt to different temperatures and nutritional conditions, exploring the sewage treatment effect of microalgae community formed by their mixed culture, under the laboratory conditions, Chlorella sp., Scendesmus obliquus, Nitzschia sp., Chlamydomonas reinhardti and Cyclotella sp. were selected, at three different temperatures of 10, 20 and 30℃ and three different nutritional conditions, with TN and TP concentrations of 8.40 and 1.97 mg/L, 12.97 and 5.70mg/L, 60.22 mg/L and 18.19mg/L respectively. Three dominant algal species featuring good tolerance as well as removal of nitrogen and phosphorus at different temperatures and nutrients were screened. The dominant algal species were further selected for algal community collocation. Based on the removal effect and stability of nitrogen and phosphorus pollutants in artificial waste-water by different algal communities, the dominant algal communities were determined. The results showed that at three different temperatures, the growth condition of Cyclotella sp. and Nitzschia sp. was stable and the removal rate of nitrogen and phosphorus was generally over 80%; In three different nutritional conditions, only the growth rate and removal rate of nitrogen and phosphorus of Scendesmus obliquus was higher. To sum up, the environmental tolerance and removal rate of Scendesmus obliquus, Nitzschia sp. and Cyclotella sp. were better. The above three algae were combined with each other. The removal rate of TN and TP was about 80% and 90% by the community combination of Nitzschia sp. and Cyclotella sp., there was no abnormal changes; The growth of the communities of Scendesmus obliquus, Nitzschia sp. And Cyclotella sp.was stable.
2021 Vol. 41 (4): 1564-1575 [Abstract] ( 309 ) [HTML 1KB] [ PDF 459KB] ( 1239 )
1576 Hydrochemical characteristics of the mountain runoff in Tarim River Basin, China
WANG Jian, HAN Hai-dong, XU Jun-li, LI Yong-shan
On the basis of regional geology, the reasons for the formation of hydrochemical components of the Mountain Runoff were analyzed, and the source of solutes and their controlling factors were discussed in Tarim River Basin, China. The results showed that the mountainous runoff was mainly composed of carbonated dissolving water of silicate rock with the dominant ion type of calcium bicarbonate (Ca-HCO3) and the secondary type of calcium/magnesium sulfate (Ca/Mg-SO4) mixture. The weighted averages of the total dissolved solids (TDS) and the total number of ions in the mountainous runoffs in the Kunlun Mountains and Pamirs Plateau were 424.02 and 356.20mg/L, respectively, which were much higher than the values of 268.43 and 220.04mg/L in the Tianshan Mountains, respectively. The differences were mainly due to that a large number of magmatic rocks spread over the Tianshan Mountains, which reduced the erosive intensity of regional hydrochemistry. With the combination of the methods of Gibbs diagram and factor analysis, it was determined that the water quality of mountain runoffs was mainly controlled by silicate weathering. The water system in the Kunlun Mountain and Pamirs Plateau was not only accompanied by evaporative salt rock weathering but also by carbonate rock weathering similar to that in the Aksu River system in Tianshan Mountains. During the weathering process, the H+ produced by sulfide oxidation inhibited the carbonation weathering, which lowered the atmospheric CO2 consumption to a certain extent, especially in the Dina, Kara Yuergun and Kashgar River basins rich in coal seams and copper mines. With the exception of fluorine (F-) and nitrate (NO3-), the concentrations of the other ions and the total ions all presented strong correlation with the rate of glacier coverage rate and the ratio of the glacial meltwater to surface runoff in the Tarim River basin. The fitted exponential equation established between the concentration of the total ion and the rate of glacier coverage conformed to the characteristics of mountain water quality in the arid area of northwest China. Nevertheless, under the interference of natural and anthropogenic processes, there existed a certain difference between the equations fitted in the Tarim River basin and on a global scale.
2021 Vol. 41 (4): 1576-1587 [Abstract] ( 235 ) [HTML 1KB] [ PDF 1264KB] ( 1761 )
1588 Denitrification and anammox processes in sediment of Mihe River, China
LI Jia-lin, QIN Song
Four sites were selected along Mihe River to sample the sediments and characterize physiochemical property to reveal denitrification/anammox processes and their constraints by isotope tracing experiment and molecular biological analysis. The results showed that the rates of denitrification varied from 151.75 to 2847.86μmol/(m2·h), and the anammox rates were in the range of 149.57 to 2109.17μmol/(m2·h). The relative contribution of anammox in the nitrogen removal was in an average of 56.1%. The nirK type was the dominant denitrifier with the abundance of 0.19×106~5.12×106 copies/g in the sediment, which was in the phylum of α- and β- Proteobacteria. The anammox bacteria marked by hzsA gene was in the range of 2.58×102~1.14×104 copies/g, which belonged to the Ca. Brocadia clades in Planctomycetes. Furthermore, the denitrification rate was positively related with TN content and PO43- concentration, while the anammox rate was positively related with TN content and negatively related with sediment density. The physiochemical property of sediment was the main condition determining the nitrogen removal rates. The results highlight that denitrification and anammox were of great significance to reduce nitrogen eutrophication, and sediment environment treatment was a considerable way to regular nitrogen removal rate.
2021 Vol. 41 (4): 1588-1596 [Abstract] ( 238 ) [HTML 1KB] [ PDF 967KB] ( 1431 )
1597 Degradation of Orange G by Fe0/peroxymonosulfate with nitrilotriacetic acid enhancement
MA Hong-fang, YANG Hao-yu, TIAN Wei-min, WU Ling-bin, CHEN Xiu-feng, ZOU Jing
Nitrilotriacetic acid (NTA) was applied to enhance and improve the oxidation efficiency of azo dyes in Fe0/PMS system. Taking Orange G (OG) as the target pollutant, the degradation efficiency of OG, the strengthening role of NTA, the effects of NTA, Fe0, PMS and general coexistence substances in water on the degradation of OG were studied in Fe0/PMS system enhanced with NTA(NTA/Fe0/PMS).The results demonstrated that the introduction of NTA could enhance the degradation of OG by Fe0/PMS system, and the initial pH had a significant effect on the enhancement. Under neutral (pH=7) and acidic (pH=3) conditions, the apparent rate constants of OG removal by NTA/Fe0/PMS system were 31.3 times and 5.5 times higher than those of Fe0/PMS system, respectively. Increasing the concentration of NTA, Fe0 and PMS facilitated the degradation of OG, but negative effects were observed when NTA or PMS concentration were over 8mmol/L and 1.0mmol/L, respectively. In the context of water quality, the presence of Cl- promoted the degradation of OG, while HCO3-, H2PO4- and Humic Acid showed different degrees of inhibition. In NTA/Fe0/PMS system, SO4·- and·OH produced at Fe0 interface was confirmed to be the dominant active species responsible for OG degradation, and heterogeneous and homogeneous activation of PMS contributed about 83.2% and 16.8% to the degradation of OG, respectively. When adding NTA to Fe0/PMS system, Fe3+/Fe2+ generated could be complexed rapidly with NTA, which not only alleviated the formation of passive layer and promoting the direct activation of PMS on Fe0 interface, but also increased the concentration of soluble iron in system, promoting the activation of PMS by homogeneous interaction. Thus, the degradation effect of OG in Fe0/PMS system was enhanced by NTA.
2021 Vol. 41 (4): 1597-1607 [Abstract] ( 220 ) [HTML 1KB] [ PDF 530KB] ( 1770 )
1608 Microwave-elutriation pretreatment and zero valent iron enhanced fermentation performance of waste activated sludge
LI Xin-chen, HE Ze-yuan, JI Fang-ying, DING Shi-lin, MAO Yuan-xiang, FANG De-xin, ZENG Yan-ting
In order to solve the problems of low dissolution rate of carbon source and low availability of released carbon source of waste activated sludge (WAS) with high solid content in microwave pretreatment, the method of elutriation was adopted, and zero valent iron (ZVI) was added to the mixture and supernatant of elutriated sludge for anaerobic fermentation to enhance the availability of carbon source. The results showed that elutriation significantly improved the carbon dissolution rate of microwave-pretreated WAS with high solid content (TS=11%~17%). Compared with non-elutriaton, the dissolution rate of carbon source of elutriating with water and alkali increased by 13%~68% and 146%~308% respectively. The addition of ZVI not only significantly improved the dissolution rate of volatile fatty acids (VFAs), but also transformed macromolecular carbon sources into low molecular carbon sources such as acetic acid and propionic acid. In the mixture, supernatant and ZVI fermentation, the dissolving-out amount of VFAs was 317and 354mg/g VSS respectively, which were 30 times higher than that in the microwave-pretreated WAS. After adding ZVI, the proportion of propionic acid, acetic acid and butyric acid respectively increased to 34%, 26% and 18% in the mixture, and 39%, 27% and 20% in the supernatant, which enhanced the utilization value of carbon source in WAS. The research showed that microwave-elutriation pretreatment combined with ZVI anaerobic fermentation technology could effectively improve the dissolution rate of efficient carbon source in WAS, which provided a new idea for the transformation of carbon source in WAS.
2021 Vol. 41 (4): 1608-1614 [Abstract] ( 235 ) [HTML 1KB] [ PDF 485KB] ( 951 )
1615 Preparation of pseudo-single crystal WO3 nanosheets and their photocatalytic performance
LI Hou-fen, XUE Shuai, CAO Ya-jie, YUE Xiu-ping, ZHANG Ai-ming, ZHOU Ai-juan, WANG Su-fang
Pseudo-single crystal WO3 nanosheets photocatalyst was prepared by regulating the reaction temperatures, pH and the ratios of precursors during the hydrothermal processes, and the morphologies, crystalline phases, compositions and charge carrier separation performance were characterized by XRD, SEM, TEM, XPS, UV-vis and photocurrent density test. The photocatalytic activity of WO3 nanosheets for Rhodamine B degradation was studied under visible light irradiation. The results showed that monoclinic WO3 nanosheets were obtained with thickness of ~10nm and side length of 300~500nm, moreover, the nanosheets were proved with continuous lattice structures, higher energy band structure and improved charge carrier separation property. Results of the photocatalytic experiments showed that the degradation process of Rhodamine B by WO3 nanosheets followed first-order kinetic equation and the reaction rate constant was 2.91h-1, which was 5.2 times higher than that of WO3 nanoparticles (0.56h-1). It was speculated that the better catalytic activity of WO3 nanosheets was due to the higher charge carrier separation efficiency. Moreover, the experiment with scavengers under visible light irradiation proved that ·OH and ·O2- were both active free radicals in the process of pollutant degradation catalyzed by WO3 nanosheets. The cycling test proved that the photocatalyst possessed good stability.
2021 Vol. 41 (4): 1615-1623 [Abstract] ( 240 ) [HTML 1KB] [ PDF 971KB] ( 1083 )
1624 Comparison of the enhanced effect of protocatechuic acid and gentisic acid on the heterogeneous UV-Fenton system with Poly-Silicate-Ferric(PSF) as catalyst
SU Xiao-xuan, XU Guo-peng, LI Xian-zhong, LIU Li-zhang, CHEN Jian-xin
The capability of protocatechuic acid and gentisic acid in enhancing the degradation of orange Ⅱ in the heterogeneous UV-Fenton system with PSF as catalyst was compared, and the relationship among iron ion conversion, H2O2 decomposition and·OH generation in the two systems was analyzed. The enhancement mechanisms of the two reagents in heterogeneous UV-Fenton system with PSF as catalyst was further discussed. The experimental results showed that both protocatechuic acid and gentisic acid could effectively promote the formation and release of Fe2+, thereby increasing ·OH concentration and promoting orange Ⅱ degradation. Compared with protocatechuic acid, gentisic acid showed better capacity for reducing PSF. As a result, higher ·OH concentration and faster orange Ⅱ degradation rate were achieved in the gentisic acid system. With the addition of 0.2mmol/L reagent, the "first" kinetic rate constant for orange Ⅱ decolorization increased from 0.11 to 1.68min-1 for the protocatechuic acid system, and to 2.48min-1 for the gentisic acid system, which increased by 14.27 and 21.55 times, respectively. During consecutive runs, both the two acids could enhance orange Ⅱ degradation. After treatment, the readsorption of Fe3+ by PSF made the total iron ion concentration in solution lower than 5mg/L, avoiding the loss of iron ions and the secondary pollution. Our results indicated that protocatechuic acid and gentisic acid were both highly effective enhancement reagents to heterogeneous UV-Fenton system with PSF as catalyst.
2021 Vol. 41 (4): 1624-1633 [Abstract] ( 275 ) [HTML 1KB] [ PDF 717KB] ( 1488 )
1634 Performance of amino acid gemini surfactant co-mixed systems in solubilization of perchloroethylene
ZHAO Han, DONG Jun, XIA Tian, LIANG Xue, LI Wen-de
The amino acid gemini surfactant N, N'-dilauroyl ethylenediamine sodium dipropionate (DLMC) and its co-mixed system were used to improve the solubility of perchloroethylene (PCE) in groundwater and to enhance the removal effect.The primary biodegradability of DLMC was determined and it was co-mixed with short-chain alcohols (isopropyl alcohol, ethanol) and traditional surfactants including sodium dodecyl sulfate(SDS), octylphenyl polyoxyethylene ether(TX-100) and polyoxyethylene dehydrated sorbitan monooleate (Tween80). The results showed that the biodegradability of DLMC was over 99%, possessing good biodegradability. Two formulations of DLMC-IPA (1:4) and DLMC-Tween80 (1:1) were selected for PCE-contaminated column flushing and their solubilizing concentrations were 18329 and 16906mg/L at 40g/L, respectively. DLMC-Tween80(1:1) showed the best flushing effect on PCE-contaminated columns with a flushing efficiency of 9.87g PCE per liter of flushing solution, which was 16% higher than that of single DLMC system.
2021 Vol. 41 (4): 1634-1641 [Abstract] ( 259 ) [HTML 1KB] [ PDF 425KB] ( 1117 )
1642 Spatial-temporal variation of dissolved inorganic nitrogen (DIN) and impacts of water mass on the reserves estimation of the total DIN content in the Yellow Sea
JIN Chun-jie, ZHANG Chuan-song, WANG Li-sha, SHI Xiao-yong, HAN Xiu-rong, TANG Hong-jie
Based on the data of 4 curies in 2013~2016, the distribution of DIN in the Yellow Sea、nitrogen pool and its influencing factors have been studied. Results showed that the average concentrations of DIN in the Yellow Sea were (5.43±4.02) μmol/L in spring, (4.47±3.16) μmol/L in summer, (7.46±3.56) μmol/L in autumn, and (5.09±2.59) μmol/L in winter, among which DIN contents reached maximum in autumn and minimum in summer, respectively. DIN concentrations declined from coastal zones to the offshore area. The DIN-rich sites near the coast were mostly centralized in the north of the Yangtze River estuary, Shandong Peninsula and Liaodong Peninsula. The main affecting factors all the year except winter were terrigenous input and the growth of phytoplankton, as the resuspension of the riverine input and sediment were the main factors affecting the distribution of DIN in winter. There was an area with high concentration of DIN(>6μmol/L) in the central area, which was co-influenced by the Yellow Sea warm current and the Yellow Sea Cold Water Mass. Cluster analysis has been used to classified the Yellow Sea water into 5 water masses, including the Yellow Sea water masses (Y), Yellow Sea cold water mass (YC), Yellow Sea warm current water (YW), Coastal water mass (CW) and Yellow Sea-East China Sea mixed water mass (YE), which was the main water mass in the researching sea area. All these water masses except for Y were seasonal. The total DIN content in the research field showed no obvious difference in all year, and their range was 1.0×106~1.5×106t. The DIN content was slightly lower in spring and summer under the influence of phytoplankton assimilation. The total DIN contents were about 1.2×106t in spring, 1.0×106t in summer, 1.5×106t in autumn, and 1.3×106t in winter, respectively. The contributions of water masses to the total DIN content were different in the varying season. In autumn and winter, Y was dominant, while in summer and spring, YW and YC played the dominant roles, respectively.
2021 Vol. 41 (4): 1642-1654 [Abstract] ( 239 ) [HTML 1KB] [ PDF 1339KB] ( 872 )
1655 The application and effectiveness evaluation of microbial separator in biocathode microbial fuel cell (MFC)
LI Chao, LIANG Dan-dan, TIAN Yan, Ravi Shanker Yadav, HE Wei-hua, FENG Yu-jie
2 litters modularized biocathode microbial fuel cells (MFCs) with microbial separator (MS) were designed and constructed for raw wastewater treatment in continuous flow mode, while the designed functions of MS were systemically investigated during the long-term operation. It was observed that the restriction of electrode reaction by electrolyte properties could be avoided by mature biofilm developed in MS, while the DO concentration could be well controlled below 0.5mg/L in anode chamber and COD concentration was also below 50mg/L in cathode chamber. Besides, the pH value between anode and cathode was also balanced by the ionic across-separator transfer. The low ionic strength of cathode may be caused by rapid aerobic metabolism process, while the difference of ionic across-separator concentration represented the great separating function of MS between anode and cathode chamber. In summary, the stable operation of MFC was attributed to the well-controlled COD, DO, and ionic cross-separator transfer. Furthermore, the technical and economic advantages of microbial separator were discussed and reviewed for pilot-scale application of MFC, which showed significant engineering meaning of practical application for microbial electrochemical equipment.
2021 Vol. 41 (4): 1655-1662 [Abstract] ( 229 ) [HTML 1KB] [ PDF 563KB] ( 964 )
1663 Simultaneous removal of Ni2+and SDBS by RGO modified mesoporous TiO2 thin films photocatalytic
LI Cui-xia, SUN Hui-zhen, JIN Hai-ze, ZHANG You-you, YANG Xuan, LI Wen-sheng
The mesoporous RGO-TiO2 thin films were synthesized by dipping-coating assisted heat treatment and ultraviolet lamp irradiation reduction with tetrabutyl titanate (TBT), natural flake graphite as raw materials and polyvinylpyrrolidone (PVP) as mesoporous template. The structure, morphology and properties of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), specific surface area (BET), UV-Vis diffuse reflectance spectra (UV-Vis DRS) and Fourier transform infrared (FTIR). The reaction property of the removal of Ni2+and SDBS by photocatalysis of mesoporous RGO-TiO2 thin films were evaluated with Ni2+ and SDBS as target pollutants. The GO amount and the effects of pH on its catalytic performance were discussed. The photocatalytic reduction of Ni2+ and photocatalytic oxidation of SDBS in Ni2+/SDBS co-existed system were further studied under the optimum condition. The results showed that the mesoporous RGO-TiO2 thin film had the highest photocatalytic efficiency for single system Ni2+ and SDBS with the content of 1.0wt% GO; The reduction efficiency of Ni2+ and the degradation efficiency of SDBS were the highest when the pH values were 7.5 and 6, respectively. In summary, the removal efficiency of Ni2+ and SDBS in the co-existed system was better than that of the single system under the additions that the amount of GO was 1.0wt% and pH≈6. The reduction rate of Ni2+ was 87.9% and the oxidation rate of SDBS was 95.5%. In this present contribution, the mechanism of synergistic photocatalysis was further explored. It can be concluded that the Ni2+ synchronous reduction occured by the photogenerated electrons and the oxidation producted CO2·- free radical when the TiO2-SDBS surface complex was oxidized under the excitation of ultraviolet light.
2021 Vol. 41 (4): 1663-1671 [Abstract] ( 210 ) [HTML 1KB] [ PDF 779KB] ( 1063 )
1672 Effect of Fe3+ on nitrogen removal of Anammox in the presence of organic matter
WANG Hai-yue, PENG Ling, MAO Nian-jia, GENG Jin-ju, REN Hong-qiang, XU Ke
The tolerance of Anammox to organic matter in the presence of Fe3+ (2.24~7.84mg/L) was investigated by running four reactors (R1control, R2 2.24mg/L Fe3+, R3 4.48mg/L Fe3+, R4 7.84mg/L Fe3+). The mechanism was clarified by using 16SrRNA high-throughput sequencing technology and qPCR. The results showed that high NH4+-N and TN removal rates (> 90%) of all four reactors could be achieved at the influent COD concentration of 50 and 100mg/L, and the presence of Fe3+ did not show the obvious positive effect. As the influent COD concentration increased to 150 and 200mg/L, the performance of Anammox was inhibited and the positive effect of Fe3+ increased. When the influent COD concentration was 200mg/L, the addition of Fe3+ (7.84mg/L) increased the NH4+-N and TN removals from 61.3% and 79.8% (R1) to 71.2% and 84.7%, respectively. 16SrRNA high-throughput sequencing results indicated the decrease of Anammox bacteria and the proliferation of denitrifying bacteria in the presence of organic matter. The presence of Fe3+ could increase the abundance of Planctomycetes. Fe3+ had promoting effects on the abundance of Anammox 16S rRNA and functional gene hzsB by qPCR data analysis.
2021 Vol. 41 (4): 1672-1680 [Abstract] ( 373 ) [HTML 1KB] [ PDF 951KB] ( 1795 )
1681 Electricity production and Rhodation B degradation in bioelectric fenton system with modified cathode
DU Mao-hua, LI Hao-xin, RENG jing, ZHAO huan, ZHANG Ji-yue, SONG You-tao
The composite electrodes were proved to be able to improve the in-situ production capacity of H2O2 in the electro-Fenton system, enhancing the efficiency of degrading dye wastewater. In this paper, the performance impacts of two composite electrodes, Fe/OC-OATC and Fe/PC, on the electro-Fenton system were investigated. We first pre-processed the electrodes with octanecyl trimethyl ammonium chloride(OATC) and phosphoric acid, then the iron was loaded on the carbon cloth to fabricate the Fe/OC-OATC electrode and Fe/PC electrode. The electrochemical properties of the two composite electrodes were analyzed through polarization curves, power density curves and cyclic voltammetry curves. The results indicated that the Fe/OC-OATC electrode had better performance in the current density, maximum power density and oxygen reduction ability tests than the Fe/PC electrode. The maximum power density of Fe/OC-OATC was 4.89W/m3, and its corresponding current density could reach 22.9A/m3. Subsequently, the effects of the bioelectric Fenton systems with Fe/OC-OATC and Fe/PC electrode were also explored in the procedure of Rhodamine B degradation. The results revealed that the Fe/OC-OATC system had a higher Rhodamine B removal rate of 96.4% than the Fe/PC system. Finally, the degradation mechanism of Rhodamine B in the two systems were investigated with the kinetic analysis and reaction mechanism analysis.
2021 Vol. 41 (4): 1681-1688 [Abstract] ( 273 ) [HTML 1KB] [ PDF 881KB] ( 2360 )
1689 Ag/TiO2 photoelectrocatalytic degradation of dye and effluent organic matter influence on its mechanism
HE Huan, MA Qi-cheng, DENG Hong-yu, HUANG Bin, PU Hong-ping, WAN Xing, PAN Xue-jun
A photoelectrocatalysis (PEC) system was constructed to degrade the methyl orange (MO). In this system, Ag/TiO2 nanotube arrays (Ag/TNTAs), used as the anode, were prepared with the combination method of anodization and electrochemical deposition, and the carbon/PTFE was used as the cathode. It was found that this Ag/TNTAs PEC system achieved a much higher degradation efficiency of 68.2% than those of photocatalysis (18.9%), electrochemical oxidation (38.2%) and direct photolysis. Besides, the addition of effluent organic matter (EfOM) from water treatment plants could promote the degradation of MO in the Ag/TNTAs PEC system when the initial EfOM concentration was equal or less than 1.0 mgC/L. when the EfOM concentration was 0.4 mgC/L, the enhancing effect achieved the high degree. However, the high concentrations of EfOM inhibited the degradation performance of MO in the PEC system. This study showed that the PEC system could catalyze the degradation of dyes efficiently, and the addition of EfOM within a certain threshold concentration range could further promote the photocatalytic degradation.
2021 Vol. 41 (4): 1689-1696 [Abstract] ( 248 ) [HTML 1KB] [ PDF 1166KB] ( 1741 )
1697 Effect of sulfadiazine on the nitrogen transformation of aquaponic systems
HU Hao-dong, GAO Hang, HU Zhen
In this study, impact of sulfadiazine, one of the typical antibiotics, on the performance and nitrogen transformation of lab scale aquaponic systems were reported. Results showed that sulfadiazine increased the growth of carps (Cyprinus carpio Linnaeus) by 17%, but had significant adverse effects on the growth of pakchoi (Brassica chinensis L.), which reduced the nitrogen utilization rate of the system from 43.66% to 21.20%, and increased its N2O conversion rate from 1.02% to 1.98%. Sulfadiazine was observed to have short-term inhibitory effects on the nitrification process of the system, however, the ammonia concentration of experimental group was decreased to the similar level as that in the control group after 32 days of adaptation. Furthermore, the abundance of ammonia oxidizing bacteria in the experimental group increased by 51.43% compared with the control group. The residual sulfadiazine in the fish was 35.23μg/kg, which was below the requirement of national standard, but the copies of sulfadiazine resistance genes sul1, sul2 and intI1 in the water increased by 7.23, 2.74 and 4.12 times. Taking the production performance and environmental friendliness into consideration, the use of antibiotics should be reduced or avoided during the design and operation of aquaponic systems and reasonable alternative measures need to be used to avoid antibiotics induced risks.
2021 Vol. 41 (4): 1697-1703 [Abstract] ( 268 ) [HTML 1KB] [ PDF 777KB] ( 1263 )
1704 Degradation of carbamazepine and diclofenac via dissimilatory Mn(IV) reduction
ZHAI Jun, HU Wei, WANG Quan-feng, YIN Xue-jiao, CHEN Ni
In this paper, the degradation of two target pharmaceuticals, carbamazepine (CBZ) and diclofenac (DCF), via dissimilatory Mn(IV) reduction was investigated in an anaerobic biological filter filling with manganese ores. The sediment from Jialing River was used as inoculum of the filter. Effects of extra organic carbon (sodium acetate) and adding extra MnO2 on degradation were also studied. The results indicated that the anaerobic biofilter column could achieve 25.23% and 32.44% removal of CBZ and DCF from 10μg/L, respectively, with no extra sodium acetate or MnO2 added. The contribution of dissimilatory Mn(IV) reduction to total CBZ removal was only 2.81% while that to DFC was 14.87%. Adding 0.5g/L of sodium acetate or 25g of MnO2 could improve the removal efficiency of CBZ by 6.35% and 4.63%, respectively, through dissimilatory Mn(IV) reduction, while no significant effect on the DCF removal was observed. This study could provide a new idea for the degradation of resistant organic pharmaceuticals.
2021 Vol. 41 (4): 1704-1710 [Abstract] ( 232 ) [HTML 1KB] [ PDF 425KB] ( 1059 )
1711 Identification of groundwater contamination sources considering parameter uncertainty
LI Jiu-hui, LU Wen-xi, CHANG Zhen-bo, WANG Han, FAN Yue
To analyze the influence of parameter uncertainty on the identification of groundwater contamination sources, a calculation model describing the relationship between hydraulic conductivity and contaminant release intensity was established through the comprehensive application of the simulation-based optimization method, sensitivity analysis method, Monte Carlo method and Kriging method. The results showed that the calculation model had high accuracy, the certainty coefficient and average relative error were 0.9895 and 4.51%, respectively; the contamination sources identification results under the influence of 8000 groups of hydraulic conductivity were calculated with the new model, which brought about 99% saving in the calculation load and time. Through quantitative statistical analysis of 8000 groups of contamination sources identification results, the contamination sources with the highest probability density were identified, along with the confidence intervals of contamination sources identification results corresponding to 80%, 60%, 40% and 20%. This study improved the applicability of simulation-based optimization method to identify groundwater contamination sources when facing the disadvantage caused by the parameter uncertainty, thus, can provide more reference for decision makers.
2021 Vol. 41 (4): 1711-1722 [Abstract] ( 286 ) [HTML 1KB] [ PDF 2718KB] ( 670 )
1723 Effects and mechanisms of modified-biochar on biodegradation of antibiotics as revealed by bacteriological characteristics
YANG Fang, JIAN Hong-xian, GAO Yue, WANG Cui-ping
Three kinds of modified-biochar including MBC350, MBC500 and MBC700, and two types of antibiotics sulfamethoxazole (SMX) and chloramphenicol (CAP), were selected to investigate effects of different MBCs on biodegradation of SMX and CAP and the bacteriological characteristics of Pseudomonas stutzeri and Shewanella putrefaciens. The results showed that in the bacterial system cultured with low-concentration MBCs, the removal of SMX and CAP mainly depended on biodegradation by P. Stutzeri and S. putrefaciens. While in the bacterial system cultured with high-concentration MBCs, the removal of SMX and CAP was mainly by the adsorption onto MBCs. The adsorption capacities of SMX and CAP onto MBCs and the bacterial growth all increased as the concentrations of MBCs increased, leading to the decrease in the concentrations of antibiotics in the solution and the biodegradation efficiency. The content of fatty acids of P. stutzeri was significantly improved, while the fatty acids synthesis of S. putrefaciens was inhabited in the presence of MBCs. In particular, the components C10:0, C15:1, cis-10 of P. stutzeri were disappeared, and the components of trans-unsaturated fatty acids of S. putrefaciens were generated, such as C14:1, cis-9 and C15:1, cis-10. Additionally, by using absolute quantitative technique, the gene copies number of P. stutzeri was clearly improved, while it was inhabited for S. putrefaciens in the presence of MBCs. But the gene copies numbers of P. stutzeri and S. putrefaciens were increased with the increasing concentrations of MBCs. Therefore, this study showed that low-concentration MBCs were conducive to the biodegradation of SMX and CAP. While the bacteriological characteristics, such as bacterial growth, fatty acid and copy number of bacterial gene expression, were all promoted in the presence of high-concentration MBCs.
2021 Vol. 41 (4): 1723-1731 [Abstract] ( 239 ) [HTML 1KB] [ PDF 1407KB] ( 1033 )
1732 Determination of trace elements in saline lakes in Tibet by ICP-MS after the solid-phase extraction
YANG Xin-xin, ZHU Zhao-zhou, HE Hui-jun, ZHANG Jing, LIU Xiao-long
A novel method was developed using a NOBIAS PA1 chelating resin with an inductively coupled plasma mass spectrometry (ICP-MS) measurement for Mn, Fe, Co, Ni, Cu, and Zn in organic-rich saline lakes. First, H2O2 was added to the samples which were subsequently irradiated with a digester containing three low-pressure ultraviolet lamps. This UV/H2O2 method could destroy the organic ligands of Co and Cu in water to reduce their interference. Then, the trace metals were pre-concentrated through a chelating resin column. The column was rinsed with an NH4AC solution to remove the loaded salts. Finaly, the trace metals were eluted with HNO3 solution and analyzed by ICP-MS. Results showed that the procedural blanks and detection limits of the trace elements were 0.49~6.43 ng/kg and 0.17~4.55 ng/kg, respectively, at a pH of 6.35 ±0.30. All trace metals were quantitative, and their recovery rates were 99%~102%. The results from the application of this method to Yagen Co Lake, Selin Co Lake, and Angren Jin Co Lake in Tibet showed that the recovery rates of Indium internal standard were >99%, and the relative standard deviations of the samples (n =3) were less than 5%. These findings suggests the method developed in this paper could be used to analyze trace metals in inland lakes, especially in organic-rich saline lakes (including salt lakes).
2021 Vol. 41 (4): 1732-1736 [Abstract] ( 209 ) [HTML 1KB] [ PDF 346KB] ( 1384 )
1737 The Effect of upflow velocity on CANON process stability and microbial community
ZHANG Kai, SUN Meng-xia, LIANG Dong-bo, WANG Jia, LI Jun
Expanded Granular Sludge Bed (EGSB) reactor was used as the start-up device of the CANON process in this experiment, in the effects of different upflow velocity on the nitrogen removal performance of the Completely Autotrophic Nitrogen removal Over Nitrite (CANON) process was investigated. The change of particle size of granular sludge in Integrated Fixed-film and Activated Sludge (IFAS) system and the biomass of biofilm were quantitatively analyzed. In addition, high-throughput sequencing analysis was carried out for microorganisms on granular sludge and biofilm to explore the characteristics of microbial community structure on different aggregates. The results showed that the total nitrogen removal rate (NRR) increased from 0.20kg/(m3·d) to 0.66kg/(m3·d) in the continuous operation process when the upflow velocity increased from 2m/h to 6m/h. The ratio of ΔNO3--N/ΔNH4+-N was steadily kept at 0.11, a realization of the efficient and stable operation of CANON. When the upflow velocity increased to 8m/h, the nitrogen removal performance of CANON process was unstable, the NRR decreased to 0.42kg/(m3·d), and the average particle size of sludge decreased from 1.3mm to 0.9mm. When the upflow velocity restored back to 6m/h, the nitrogen removal performance of CANON process gradually recovered. Ultimately, the NRR was stabilized at 0.60kg/(m3·d), the average particle size of sludge was restored to 1.2mm, and the specific growth rate of biofilm biomass was 0.0024d-1. High throughput sequencing showed that Aerobic Ammonia Oxidation Bacteria (AerAOB) functional bacteria Nitrosomonas (2.45%) and Anaerobic Ammonia Oxidation Bacteria (AnAOB) functional bacteria Candidatus kuenenia (2.38%) were the main genera in the granular sludge. The main bacteria in the biofilm were AnAOB functional bacteria Candidatus kuenenia (9.78%) and Candidatus brocadia (4.23%), while a small amount of AerAOB functional bacteria Nitrosomonas (0.40%) were also detected. The results suggested that there were some differences in two microorganisms in different aggregates.
2021 Vol. 41 (4): 1737-1745 [Abstract] ( 226 ) [HTML 1KB] [ PDF 620KB] ( 828 )
Solid Waste
1746 Research advances in highly-efficient detection methods for nitrogen, phosphorus and antibiotics in livestock and poultry manure
HAO Si-bei, LIU Cheng-bin, CHEN Xiao-yan, MAO Shun
In this article, conventional detection methods and emerging detection techniques for nitrogen, phosphorus, and antibiotics in feces have been systematically reviewed to identify the bottlenecks and future research directions. For the conventional feces detection methods, they are of high accuracy and sensitivity, but often carried out in professional laboratories or require the use of large instruments. It is quite challenging to meet the need of rapid detection in in-situ or online monitoring situations. Therefore, new detection technologies for nitrogen, phosphorus, and antibiotics in feces are highly needed. Nitrogen, phosphorus, and antibiotics in feces can be extracted by pretreatment, and then be analyzed with simple and convenient electrochemical or fluorescence methods to achieve rapid measures in in-situ analysis or online monitoring settings. Given current technologies, highly efficient detection technologies for pollutants in feces have great potentials and demand in the future. The applications of electrochemical and fluorescence methods in nitrogen, phosphorus, and antibiotics detection in feces need continuous support in fundamental research and technological innovations.
2021 Vol. 41 (4): 1746-1755 [Abstract] ( 251 ) [HTML 1KB] [ PDF 605KB] ( 1481 )
1756 Pyrolysis kinetics study of takeaway plastic packaging—Based on model-free and model-fitting method
YIN Feng-fu, ZHUANG Qian-xiao, CHANG Tian-hao, SUN Qi-kun
Thermogravimetric analysis for components of takeaway plastic packaging was carried out under non-isothermal conditions. The results showed that the pyrolysis processes of the single components of PP, HDPE, PS, and the mixture (PP/HDPE/PS) were finished in one step. For the complex pyrolysis reaction with mixed plastics, a model-free method combined with the model-fitting method was proposed to obtain the complete set of kinetic parameters, which made the results more reliable. The kinetic parameters of a single component and the mixture in the pyrolysis process were studied with model-free methods (K-A-S, F-W-O and Starink). In pyrolysis processes, the average activation energy (E) of PP, HDPE, PS and PP/HDPE/PS reached 224.7, 238.5, 194.1 and 179.3kJ/mol, respectively. Based on the activation energy obtained by the model-free method and the results of model fitting (Malek and C-R), the pyrolysis mechanism of a single component and the mixture was random nucleation followed by growth when the heating rate was 20K/min. Moreover, the compensation effect between the kinetic parameters was analyzed to establish the compensation effect equations. This study can provide support for the optimization of the pyrolysis process parameters of takeaway plastic waste and the design of the pyrolysis reactor.
2021 Vol. 41 (4): 1756-1764 [Abstract] ( 253 ) [HTML 1KB] [ PDF 659KB] ( 867 )
Soil Pollution Control
1765 Spatial variation and health risk assessment of thallium in floodplain soil in “Three Rivers” regions of southwest China
LIU Fu-tian, WANG Xue-qiu, CHI Qing-hua
Based on the analysis of thallium content in floodplain soil samples obtained by the China Geochemical Baselines project in "Three Rivers" regions of southwest China, the pollution status of the thallium in soil of the study area was comprehensively evaluated by multiple methods. Results showed that, the thallium content in top soil of the region was 0.17~2.65mg/kg with the mean of 0.80mg/kg and the coefficients of variation was low, which was slightly higher than soil background value of China and slightly lower than that in deep soil. The characteristics of thallium content in the top/deep soil were mainly controlled by the natural geological background, and its overall trend was "north was higher than south, and west was higher than east". Based on the background of related elements of soil in different parent rock areas in China, the parameters of enrichment coefficient, geoaccumulation index, potential ecological risk with the mean 1.30, -0.41 and 12.48, respectively, and non-carcinogenic health risk assessment with hazard quotient less than 1 all showed that the thallium contamination level of soil in the study area was generally low and there was no non-carcinogenic health risk of heavy metal of thallium in the soil, which essentially reflected that there had the characteristics of low pollution and low health risk of thallium pollution in soil of the study area under the control of natural geological background. Meanwhile, there was a certain amount of man-made pollution with a tendency of "north was lighter than south, and west was lighter than east" in the study area, reflected by the distribution characteristics of thallium content of soil in different land use field and the ratio of thallium content in top and deep soil. Comprehensive analysis showed that, the mining activities related to lead and zinc minerals in the study area might be the main source of man-made thallium pollution. Some parts of the study area had a certain degree of pollution and potential health risks due to the superposition of man-made pollution and natural geological background, including the south of Drung river basin, south central Nujiang river basin, the north and south Lancang river basin and south central Yuanjiang river basin, and these areas should attract people's attention to thallium pollution in soil.
2021 Vol. 41 (4): 1765-1777 [Abstract] ( 303 ) [HTML 1KB] [ PDF 3235KB] ( 1644 )
1778 Effects of carbon-enrich silicon fertilizer on the community characteristics of iron-reducing bacteria in paddy fields
LIN Mei-fen, ZHENG Yi, WANG Xiao-tong, XU Xu-ping, WANG Wei-qi
In order to explore the relative abundance, diversity and community structure of iron-reducing bacteria (FeRB) in paddy fields of Fuzhou Plain, by setting up the control group and the treatment groups with three dosage levels (300, 600 and 900kg/hm2) of carbon-enrich silicon fertilizer (CESF). The results showed that the application of CESF facilitated the growth and reproduction of FeRB, among which 600kg/hm2 treatment had the most significant impact on the growth of FeRB (P<0.05). According to the Shannon index, the diversity of FeRB was decreased by the three treatment groups during the jointing stage of late rice. The diversity index of the 300kg/hm2 treatment group decreased most significantly, which was 29.4% lower than the control group. In the jointing stage of early and late rice, a total of 5 phyla have been identified in the soils. The total proportion of Proteobacteria, Bacteroidetes and Firmicutes was over 95% on average, and they were the dominant bacteria phyla in paddy fields. After application of CESF, the relative abundance of Bacteroides in the soil at early rice jointing stage was significantly increased (P<0.05), while that of Anaeromyxobacter was decreased. In addition, environmental factors were correlated with relative abundance of FeRB in the soils. The relative abundance of Desulfovibrio was significantly and positively correlated with soil pH (P<0.05). The relative abundance of Anaeromyxobacter was significantly and positively correlated with soil temperature (P<0.05). The above studies concluded that diversity and community structure of FeRB were significantly affected by CESF in paddy fields.
2021 Vol. 41 (4): 1778-1789 [Abstract] ( 218 ) [HTML 1KB] [ PDF 1354KB] ( 1237 )
1790 Immobilization remediation of Cr-contaminated soils by hydrocalumite and the relevant risk assessment
CHEN Xiao-chen, YAO Cong-cong, ZHAO Tong, XU Jia-yan, BU Ya, ZHANG Wen-qing, LIU Yuan-yuan, DIAO Guo-wang, ZHANG Jian-yu
Five typical Chinese soils, including brown soil, red soil, yellow soil, black soil and cinnamon soil, were collected and artificially contaminated with Cr(VI) to a concentration of 80mg/kg. Hydrocalumite, a promising layered double hydroxide, was applied as a first attempt to immobilize the Cr-contaminated soils. The remediation effects were comprehensively evaluated on soil basic physicochemical properties, and fractionation, ecological risk and health risk of soil Cr. The relevant mechanisms and cost were discussed. Results showed that hydrocalumite significantly increased soil pH, and effectively reduced the Cr activity (59.09%~79.22%), ecological risk (14.17%~57.66%) and health (carcinogenic) risk (13.04%~63.04% in gastric phase and 22.73%~56.60% in small intestinal phase) of soil Cr. In addition to active Cr fraction, inactive Cr fraction also contributed to its ecological and health risks before and after remediation. Hydrocalumite could not only transform active Cr fraction into inactive precipitated fraction for a partial reduction or a complete elimination of its ecological risk or health risk, but also further suppress the dissolution of other inactive Cr fraction in certain soils in the TCLP or in vitro test. Regarding the reagent cost, a reasonable 6.4CNY could cover the remediation of 1m3 of actual construction land with a Cr(VI) concentration of 80mg/kg, under the relatively optimum dosage (mCr:mhydrocalumite=1:20). As a new-type immobilizing agent for Cr-contaminated soils, hydrocalumite is highly expected to make contributions to the improvement of soil quality and public health.
2021 Vol. 41 (4): 1790-1798 [Abstract] ( 289 ) [HTML 1KB] [ PDF 522KB] ( 1635 )
1799 Distribution characteristics and pollution assessment of 238U and 226Ra in soils surrounding a uranium mining area
JIANG Wen-bo, GAO Bai, ZHANG Hai-yang, LIN Cong-ye, WANG Juan, Yi Ling
To determine the pollution intensity and range of the soil pollution source surrounding a uranium mining area, and quantify the pollution sources that need to be treated, we carried out a field investigation and statistical analysis of 238U and 226Ra activities in the soil layers of 0.0~0.2,0.2~0.4,0.4~0.6,0.6~0.8,0.8~1.0m around the uranium mine, and thereby determined the spatial distribution of radionuclide contamination and its effectiveness, as well as using 226Ra/238U to reflect weathering degree. The results demonstrated that the highest concentrations of 238U and 226Ra were 813.44~5059.20 and 737~4536Bq/kg respectively at 0.0~0.2m soil depth. The concentrations of 226Ra and 238U decreased with the increase of depth, and the concentrations of 238U and 226Ra at the depth of 0.6~1.0m were still higher than the soil decontamination standard concentration (370Bq/kg) regulated by the United States Nuclear Regulatory Commission (NRC) on the residual radionuclides in the decommissioning of uranium mines and Hydrometallurgical facilities. Therefore, for the soil treatment in the study area, the needed treatment soil depth should not be less than 1m. The results of pollution assessment showed that in the study area, the soil area with severe to extremely severe pollution and strong ecological risk hazards accounted for the highest proportion; with the increase of the distance from uranium mining area, the pollution degree of 226Ra and 238U decreased, and the potential ecological risk decreased as well.
2021 Vol. 41 (4): 1799-1805 [Abstract] ( 227 ) [HTML 1KB] [ PDF 604KB] ( 958 )
Environmental Ecology
1806 Occurrence and ecological risk of typical DBPs in Chinese surface water
LUO Ying, LIU Na, SUN Shan-wei, HOU Song, GUO Chang-sheng, XU Jian
Trihalomethanes (THMs) and haloacetic acids (HAAs), the disinfection by-products (DBPs) in surface water, have given rise to major concern in recent years. In this study, exposure and ecotoxicity data of 4 DBPs (trichloromethane, tribromomethane, dichloroacetic acid and trichloroacetic acid) were collected from literature published in China and abroad, and a multiple-level environmental risk assessment was performed. THMs and HAAs were collected from previous studies, with concentrations range from n.d. to 51μg/L. Predicted no effect concentration (PNEC) for trichloromethane (TCM), tribromomethane (TBM), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was based on acute and chronic toxicity data. The PNEC of TCM, TBM, DCAA and TCAA derived from acute and chronic toxicity data which based on endpoints of survival, reproduction and development, with concentrations range from 0mg/L to 44.88mg/L, 0.006mg/L to 0.956mg/L, respectively. Besides, risk quotient (RQ) and probabilistic ecological risk assessments (PERA) were calculated by exposure data, and PNEC of acute and chronic toxicity data. The results showed that RQ were less than 1. TCM of probabilities of exceeding NOEC based on chronic toxicity for 1% of the species were 78.86%. And TCAA of probabilities of exceeding NOEC based on chronic toxicity for 1% of the species were 20.61%. Based on these results, the ecological risks of TCM and TCAA in Chinese surface water were low.
2021 Vol. 41 (4): 1806-1814 [Abstract] ( 439 ) [HTML 1KB] [ PDF 448KB] ( 1320 )
1815 The migration and transformation of light non-aqueous fluid in silty clay
RUAN Dong-mei, BIAN Jian-min, WANG Qian, WU Juan-juan, WANG Yu, SUN Xiao-qin
The LNAPL longitudinal migration transformation model was established by COMSOL software, and was solved with the finite element method. It was applied to predict the distribution of pollutants, meanwhile parameter sensitivity was performed with local analysis method. The research results showed that most of the LNAPL aggregated above the water surface and formed a high mass distribution peak area, and a small part overcame the capillary pressure and migrated downward. In the free phase migration range, the dissolved phase concentration reached or approached the saturated solubility. When the top pollution source disappeared, the precipitation gradually lowered the maximum saturation and the depth of its concentration occurrence. The local low permeability lens in the porous medium caused of the pollutants blocked which will be accumulated on its surface and formed a pollution pool. The sensitivity analysis results demonstrated that the permeability coefficient was a key parameter to control the longitudinal migration speed and saturation distribution of LNAPL.
2021 Vol. 41 (4): 1815-1823 [Abstract] ( 340 ) [HTML 1KB] [ PDF 1062KB] ( 1239 )
1824 Groundwater, river water and lake water transformations in a typical wetland of Poyang Lake
XU Xiu-li, LI Yun-liang, TAN Zhi-qiang, GUO Qiang
The characteristics of hydrogen and oxygen isotopes in rainfall, lake water, river water, and wetland groundwater were investigated in a typical delta wetland of Poyang Lake during the period from April to October in 2018. Based on the δ18O-δD relationships, the transformations between these different water sources in different hydrological periods were quantified. The contribution rates of different water bodies to wetland groundwater were further calculated using a mixed source model. The results showed that, in general, the rainfall δ18O and δD values were lower in June and July and were higher in other months of the year. The rainfall isotopes exhibit obviously seasonal variations and the associated amount effect. The variation trends of isotopes in river water and lake water were consistent with those of the rainfall. In addition, the river water and lake water were isotopic enriched due to intense evaporation, while the variation amplitudes were less than the rainfall isotopes. The results also revealed that the groundwater isotopes in wetland were relatively stable with small seasonal variations. On average, the groundwater δ18O and δD values (-5.26‰, -31.1‰) were higher than those of the rainfall (-6.32‰, -40.1‰), and were lower than those of the lake water (-3.60‰, -26.4‰), but were close to the river water (-5.09‰, -34.4‰). This result indicated that the wetland groundwater was jointly influenced by rainfall, river water and lake water. During the water level rising period (April-May), the river water was mainly recharged by the rainfall and the catchment groundwater. During this period, the lake water was mainly supplied by the rainfall and the river water, while the wetland groundwater was mainly replenished by the antecedent precipitation and the river water. However, the contribution of river water to the wetland groundwater was the greatest among these water sources. During the high water level period (June-August), the wetland groundwater was mainly recharged by lake water and the river water, and the contribution rate of lake water was higher than 50%. During the falling water period, results showed that the wetland groundwater discharged to the surrounding river channel and the lake.
2021 Vol. 41 (4): 1824-1833 [Abstract] ( 252 ) [HTML 1KB] [ PDF 719KB] ( 1237 )
1834 Spatial analysis and simulation study of rainfall runoff pollution for a tidal river network
ZHANG Feng-shan, SHANG Ming-zhu, ZHAO Peng-xiao, CHENG Kai-yu, TANG Ying-dong, WEI Jun
To explore the spatial distribution characteristics and pollution pattern of non-point source pollution of the tidal river network in the Maozhouhe River basin, the river network water quality under typical rainfall scenarios was simulated and analysed based on spatial analysis, statistical analysis and hydrodynamic-water quality coupling simulation method. An ecological water supply optimization strategy based on the target of water quality improvement was proposed. The results showed that the combination of hierarchical clustering aggregation algorithm and K-means can preferably distinguish the level and class of non-point source pollution. The water quality of the Shiyanqu River and the middle and upper reaches of the Songganghe River recovered slowly after rain fall due to the high non-point source pollution load and the lack of ecological water supply. A local optimized ecological water supply scheme was proposed based on the principle of constant amount of water replenishment. The recovery speed of water quality in key polluted rivers after rainfall was doubled by the optimized results, and the overall stability of river water quality in the basin was improved. The research conclusions provide support to the further understanding on the water pollution characteristics of the Maozhouhe River basin and the delicacy management of watershed water environment.
2021 Vol. 41 (4): 1834-1841 [Abstract] ( 268 ) [HTML 1KB] [ PDF 2199KB] ( 1123 )
1842 A review of chlorinated/brominated polycyclic aromatic hydrocarbons in the environment and human: Sources, analysis methods and pollution characteristics
LIU Ming-yang, LI Hui-ru, SONG Ai-min, HU Jian-fang, SHENG Guo-ying, PENG Ping-an
Chlorinated/brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) were a class of emerging persistent toxic contaminants that demonstrating similar chemical structures and carcinogenicities with dioxins and PAHs. Their behaviors, fates, and potential risks in environments were of great concern. This study retrieved the Web of Science Database with the topics including "Cl-PAH*" OR "Br-PAH*" OR "H-PAH*" OR "chlorinated PAH*" OR "brominated PAH*" OR "halogenated PAHs" OR "chlorinated polycyclic aromatic hydrocarbon*" OR "brominated polycyclic aromatic hydrocarbon*" OR "halogenated polycyclic aromatic hydrocarbon*", and reviewed the research progress of the sources, pollution characteristics and analysis methods of Cl/Br-PAHs focusing on the environmental matrix and human beings. The results showed that 225 papers in total within this topic were published by Jan. 2021. The existing findings showed that:Cl/Br-PAHs were mainly generated from thermal processes such as waste incineration, vehicle exhaust, metal smelting, electronic waste recycling, etc., as well as some photochemical processes; So far, Cl/Br-PAHs were found ubiquitous in various environments worldwide, and demonstrated persistence, long-distance transportability and bioavailability; It was documented that Cl/Br-PAHs had similar or stronger toxicity compared to their parent PAHs. However, their formation mechanisms and environmental behaviors were still unclear; An effective and precise analytical method was still unavailable, leading to very limited reports on Cl/Br-PAH compounds in environments and the overall research area on this topic was still in its infant stage. Based on the current research status and knowledge gaps of Cl/Br-PAHs, more attention should be paid to their high-throughput and precise analytical methods, emission fingerprints, environmental behaviors, and potential risks in the future.
2021 Vol. 41 (4): 1842-1855 [Abstract] ( 349 ) [HTML 1KB] [ PDF 513KB] ( 2427 )
1856 Sources tracing and evolution model of inorganic nitrogen of groundwater in sedimentary basin
LI Xiao, WANG Xiao-guang, CHAI Lu, ZHU Wei, HE Hai-yang, WANG Chang-qi
Based on Fuyuan area in Sanjiang Plain, a typical agricultural area of a sedimentary basin, the study analyzed the regional hydrochemical effect and inorganic nitrogen pollution characteristics with the hydrochemical methods and GIS technology. The nitrogen source and contribution ratio of each pollution source were determined through the distribution characteristics of nitrogen, oxygen bistable isotopes and stable isotope analysis model (SIAR). With the understanding of affecting factors on the changes of nitrogen concentration, the regional hydrochemical evolution model of nitrogen were established. These results showed that 56.52% of groundwater had ammonia nitrogen concentration exceeding the standard rate in the study area and the average milligram equivalent percentage accounted for 55.50% of the total inorganic nitrogen, which was the most important index of groundwater inorganic nitrogen pollution. Soil organic nitrogen, manure sewage and ammonia fertilizer were the main sources of nitrogen pollution in the runoff recharge area, and the contribution ratios of each pollution source was 40.49%, 30.24% and 29.27% respectively in descending order. The groundwater recharge area was the most polluted area of ammonia nitrogen, while the discharge area was the relatively serious pollution area of nitrate nitrogen. The redox conditions were the key factor affected the nitrogen concentration. In the process of spatial and temporal evolution of nitrogen, the nitrogen concentration in the first terrace and floodplain area increased in varying degrees except the natural hydrochemical state in the second terrace.
2021 Vol. 41 (4): 1856-1867 [Abstract] ( 207 ) [HTML 1KB] [ PDF 3681KB] ( 1318 )
1868 Identifying the critical sources areas of non-point particulate phosphorus based on an index approach in R: A case study in red soil hilly micro-watershed
SU Jing-jun, ZHAO Hong-tao, JIAO Ru-yuan, FANG Zhi-da, YANG Xiao-jing, LI Xu-yong
This study developed a watershed-scale non-point source (NPS) particulate phosphorus (PP) index based on R statistical language and applied it in a red soil hilly subbasin. The results indicated that watershed soil erosion rates ranged from 0.7 to 15244.2 t/(km2·a), and 59% of the watershed area exceeded the regional soil erosion threshold. The average watershed NPS PP load was 0.86 kg/hm2 and approximately 14% of the watershed area exceeded the NPS P loss threshold. Despite the fact that dominate soil erosions in the watershed were slight to mild, the small areas (7.2%) categorized as moderate to severe erosions contributed considerably larger shares to the total watershed loads of erosion and NPS PP loss (31%~43%). The critical sources areas (CSAs) for soil erosion and NPS PP loss were identified as 6.4 km2 in area, mainly consisting of wood land, crop land and orchard land, which were adjacent to streams (≤ 800m) and with low to gentle slopes (<25°). The soil P enrichment due to excessive fertilization, as well as the high erosion potential facilitated the formation of these CSAs. The CSAs were further divided into zones according to land uses, hydrological distances and slopes, on which different management practices and strategies were recommended to target the erosion and NPS PP loss.
2021 Vol. 41 (4): 1868-1877 [Abstract] ( 222 ) [HTML 1KB] [ PDF 1787KB] ( 1000 )
Environmental Toxicology and Health
1878 Pollution characteristics and source analysis of PBDEs in dust in typical public places
JIN Man-tong, LU Zhu-hao, LI Lin-jun, SHEN Xue-you, ZHANG Shun-fei
In order to explore the pollution characteristics of SVOCs represented by polybrominated diphenyl ethers (PBDEs) in typical indoor public places and the relationship with materials, dust samples were collected and analyzed in 5 types of typical public places, PBDEs concentration in different indoor materials were analyzed by using environmental simulation cabin, then the coefficient of volatile strengths of PBDEs (KvsPBDEs), decay half-life was determined. The relationship between the concentration of PBDEs and different indoor materials was analyzed by PCA. The results revealled that the concentration of ∑14 PBDEs in dust in 5 typical Hangzhou indoor public places from high to low was:Internet cafes (2471.75ng/g), electronic markets (1071.77ng/g), building materials markets (900.63ng/g), shopping malls (441.27ng/g), and book cities (243.36ng/g). Among the selected 10 pollution source materials, the highest concentration of ∑14 PBDEs was thermal insulation cotton (91.61μg/g), and the lowest was circuit board (7.97μg/g), the highest KvsPBDEs was wire (14.04×104μg/(g×m2)), and the lowest was fiber wallpaper (0.87×104 μg/(g×m2)), finally, plastic carpet, insulation and cotton fiber wallpapers ecay half-life (192,375,61d) at 40℃ were determined. It revealled that PBDEs concentration in indoor public places was related to different indoor materials. PBDEs in Internet cafes mainly come from fiber wallpaper and wires, PBDEs in shopping malls and book cities mainly come from ceramic flame-retardant cloth and blended carpets, PBDEs in the building materials markets mainly come from thermal insulation cotton, circuit boards and plastic wallpaper, and PBDEs in the electronic markets mainly come from fiber flame retardant cloth and wires.
2021 Vol. 41 (4): 1878-1885 [Abstract] ( 307 ) [HTML 1KB] [ PDF 571KB] ( 1521 )
1886 Residues of halogenated flame retardants in wild fish from an abandoned e-waste site in South China
WU Jiang-ping, FENG Wen-lu, WU Si-kang, HU Yu, MAI Bi-xian
Due to its serious environmental pollution, crude e-waste dismantling has been banned in China, leaving many abandoned e-waste sites. However, the levels and the ecological risks of e-waste derived contaminants in these sites were not fully understood. In the present study, the concentrations of several halogenated flame retardants (HFRs), including polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), Dechlorane Plus (DP) and alternative brominated flame retardants (ABFRs), were examined in wild mud carps and crucian carps collected from an abandoned e-waste site in South China. The concentrations of ∑HFRs in mud carps and crucian carps ranged from 1230 to 1680ng/g and from 141 to 650ng/g, respectively. These concentrations were 1~2 orders of magnitude higher than those detected in the same species from a reference site, suggesting heavy contamination of HFRs, despite of the fact that primitive e-waste recycling has been regulated for several years. Among the HFRs measured, PBDEs were detected at the highest concentrations contributing 96% and 89% to ∑HFRs in mud carp and crucian carp, respectively. There were significant differences in both the concentrations, and compositions of HFRs between mud carp and crucian carp, possibly resulting from the differences in the feeding habits, trophic level and lipid content between the two fish species. The result of risk assessment showed that PBDEs posed an important risk both for the fish and for piscivorous wildlife.
2021 Vol. 41 (4): 1886-1892 [Abstract] ( 213 ) [HTML 1KB] [ PDF 357KB] ( 1139 )
1893 Occurrence and ecological risk of parabens in water environment in Xiong'an New Area
ZHAO Xue, ZHENG Yi, FU Cai-xia, QIU Wen-hui, WANG Wen-ke, DUAN Lei, ZHAO Ting
Surface water (SW) and groundwater (GW) samples were taken from Xiong'an New Area and the vicinity of Baoding in June 2019. Concentrations of seven parabens were determined for these samples and the associated ecological risk was assessed. The detection rates of MeP and PrP were 100%. MeP was found to be the predominant compound in SW samples, with a mass contribution of 93.4%, and MeP, EtP and PrP were the predominant compounds in GW samples, with a total mass contribution of 98.0%. The GW samples overall had a higher content of parabens than the SW samples. In space, the SW samples downstream Baiyang Lake showed higher concentrations of parabens than those upstream of Baiyang Lake, while GW samples taken from Anxin County had relatively high concentrations of parabens (10.1ng/L on average). Overall, the water pollution level of parabens, as well as the associated ecological risk, was relatively low in the study area. This study offered reference values for water quality management in the future development of Xiong'an New Area, and sheds light on studies of other PPCPs in the same area.
2021 Vol. 41 (4): 1893-1899 [Abstract] ( 267 ) [HTML 1KB] [ PDF 522KB] ( 1294 )
Environmental Microbiology
1900 Promotion effect of Microcystis aeruginosa on defluorination by coagulation and its mechanism analysis
XIANG Yu, XU Hui, LI Kun, WANG Xi, WU Hao-Lan, FAN Hua
Microcystis aeruginosa and aluminum chloride (AlCl3·6H2O) were chosen to research the effect of algae on the coagulation removal mechanism of fluoride through 3D-EEM, FE-SEM. The results showed that Microcystis aeruginosa had an obvious promotion effect on defluorination under the conditions of pH 7.0, 8.0, 9.0 and Al dosage of 20.0~80.0mg/L, which was mainly due to the surface adsorption of fluoride by algal flocs. Microcystis aeruginosa and the hydrolyzed products of coagulant aggregated into larger flocs by bridging and sweep flocculation. The larger the floc size was, the larger the fluoride removal rate was. When the pH value was 7.0 and the Al dosage was 40.0mg/L, the flocs reached the maximum particle size (500μm), and the fluoride removal rate was the largest (77.37%). When the Al dosage was 80mg/L, the algal cells were seriously damaged and the organic matter was released, which hindered the defluorination process. The results of floc breakage and adsorption experiments showed that certain strength breakage of algae floc could increase the adsorption site and thus improved the removal rate of fluoride. Excessive breakage led to too small particle size of algae flocs, resulting in the reduction of fluoride adsorption efficiency.
2021 Vol. 41 (4): 1900-1908 [Abstract] ( 243 ) [HTML 1KB] [ PDF 4384KB] ( 853 )
1909 Influence of RSI-MO process on biogas desulfurization and analysis of microbial communities
RUAN Ren-jun, LI Jia-le, OU Kun-xuan, ZHAO Chang-shuang, SUN Jun-wei, CAO Jia-shun
To achieve in-situ deep desulfurization of biogas derived from waste-activated sludge (WAS) anaerobic digestion, an integrated approach of optimal rusty scrap iron addition (20g/L) with micro-oxygen injection (RSI-MO) was constructed to disclose their combined influences on the performance of in-situ desulfurization. The operation of semi-continuous anaerobic/microaerobic reactor included seven stages (P1~P7). The operation of first stage (P1) was set as the control. The addition of RSI was started at the second stage (P2). The oxygen was introduced in P3 stage, and the concentrations were gradually increased from P3 to P7 stages. The results showed that MO induced the microbial sulfide oxidation by stimulating sulfur-oxidizing bacteria (SOB), and simultaneously promoted the chemical corrosion on iron to generate iron-sulfide precipitation. From P1 to P7, the synergistic effects of RSI and MO contributed to the hydrolytic-acidogenic efficiency. However, the overdose of oxygen inhibited the activities of methanogenic microorganisms, which caused the accumulation of VFAs. To demonstrated the combined effects of RSI and MO on the microbial diversity and abundance, the microbial communities in sludge samples of P1, P2 and P6 were analyzed via the high-throughput sequencing technology. The microbial analysis suggested that the RSI addition stimulated the activity of hydrogen-producing microorganisms (Syntrophobacter fumaroxidans), acetate-producing microorganisms (Roseomonas lacus, Sporomusa silvacetica) and methanogenic microorganisms (Methanoculleus palmolei, Methanolinea tarda, Methanosarcina mazei, Methanosaeta concilii, Methanococcus aeolicus) while the MO stimulated the activity of SOB for biological desulphurization enhancement.
2021 Vol. 41 (4): 1909-1916 [Abstract] ( 240 ) [HTML 1KB] [ PDF 923KB] ( 847 )
1917 Spatiotemporal distribution of aerobic ammonia-oxidizing microorganisms in sediments of Lake Donghu, Wuhan
ZHANG Zhi-zhong, CHENG De-xi, LIAO Ming-jun, WANG Shu-lian, LI Zhu
The amoA gene abundances of ammonia-oxidizing archaea (AOA-amoA) and bacteria (AOB-amoA) in the sediments of Lake Donghu, Wuhan, was determined by the real-time quantitative polymerase chain reaction (qPCR). Moreover, the influence of nitrogen content on the temporal and spatial distribution of AOA and AOB was analyzed. The results showed that the abundance of AOA-amoA was higher than that of AOB-amoA, indicating greater contribution of AOA-amoA to the ammonia oxidation process. Meanwhile, the abundances of AOA-amoA and AOB-amoA decreased with elevated sediment depth. In addition, the concentrations of total nitrogen (TN), ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3--N) and nitrite nitrogen (NO2--N) in interstitial water were 6.28~33.56, 2.71~22.7, 0.12~0.98 and 0.01~0.13mg/L, respectively. The average concentrations of TN, NH4+-N, NO3--N and NO2--N in overlying water were 1.68, 0.79, 0.16 and 0.04mg/L, respectively, while in surface water were 1.34, 0.62, 0.11 and 0.03mg/L, respectively. These results suggested that the sediments of Lake Donghu were important sources of nutrient. In addition, the abundance of AOA-amoA was positively correlated with the concentrations of NH4+-N and NO2--N in interstitial water (P<0.05), while the abundance of AOB-amoA was positively correlated with the concentration of NO2--N in interstitial water (P<0.05).
2021 Vol. 41 (4): 1917-1924 [Abstract] ( 248 ) [HTML 1KB] [ PDF 695KB] ( 842 )
1925 Study on the algae inhibition effect and mechanism of the fermented liquid of rice straw
HU Chun-xia, CHEN Bo, ZHANG Ting-ting
In order to use agricultural waste rice straws to inhibit algae growth more efficiently, this study experimented specific fermentation of different rice straws, measured the allelopathy performance of the fermentation liquids on common freshwater algae, and discussed the mechanism of fermentation liquid with strong algae inhibition. The results showed that compared with ordinary rice straw fermentation liquids, the fermentation liquid with rice tillering branch had significantly better inhibitory effect on Microcystis aeruginosa (P<0.05), and the inhibition rate after 72h treatment was 93.21%, then increased to 97.96% at 168h. With the treatment of the ordinary rice straw fermentation liquid, the corresponding inhibition rate at 120h was only 68.20%, then decreased significantly to only 27.65% at 168h. The Eh50 was 14.073h for the former and 21.036h for the latter liquid. The rice tillering branch fermentation liquid had better inhibitory effects on cyanobacteria (M. aeruginosa) and green algae (Chlorella pyrenoidosa, Scenedesmus obliquus), and had the best inhibitory effect on M. aeruginosa (P<0.05). Under the stress of rice tillering branch fermentation liquid, the contents of chlorophyll a, phycocyanin (PC) and allophycocyanin (APC) of M. aeruginosa decreased, the autofluorescence value of algal cell chlorophyll decreased continuously, and the algal cell structure was destroyed. It was speculated that one of the anti-algae mechanisms of rice tillering branch fermentation liquid might use the photosynthetic system of algae cells as its attack target to inhibit the growth of algae, and ultimately destroy the cell structure and cause cell apoptosis.
2021 Vol. 41 (4): 1925-1931 [Abstract] ( 213 ) [HTML 1KB] [ PDF 413KB] ( 1429 )
Environmental Impact Assessment and Management
1932 The role of willingness to accept in determining the upper or lower limit of eco-compensation standard
PAN Mei-chen, SONG Bo
Willingness to accept (WTA) is one of the common methods to calculate eco-compensation standards. Proper use of WTA method is very critical to reaching the reasonable eco-compensation standards. This study reviewed studies published in Chinese domestic journals associated with WTA during the last 12 years, and found that there was no consensus on whether WTA should be regarded as the upper or lower limit of eco-compensation standards. While the majority of the literature acknowledged that assuming WTA as the lower limit of the compensation standard was not logically rigorous, this article argued that the process of establishing eco-compensation standards can be regarded as a bargaining process between the payee and the payer and the WTA is actually the bid value of the payee. Therefore it should be used as the upper limit of the eco-compensation standard. In addition, it was found that the acceptable range of eco-compensation standards on the basis that WTA and WTP not be a precise amount but an imprecision interval. When the WTA was higher than WTP, there was still possibility for negotiation success; otherwise, the actual eco-compensation standards had wider range and the policy maker had more flexibility for decision.
2021 Vol. 41 (4): 1932-1939 [Abstract] ( 233 ) [HTML 1KB] [ PDF 412KB] ( 1420 )
1940 Study on the economic effects of Xin'an river basin horizontal ecological compensation
LIU Cong, ZHANG Ning
Taking the pilot policy of Xin'an river basin horizontal ecological compensation as a quasi-natural experiment, the difference-in-difference method was used to systematically examine the impact of pilot policy on the economic development of the upper and lower reaches of Xin'an river basin, based on the county-level panel data in Anhui and Zhejiang in 2001~2017. The results showed that the pilot policy had restrained the economic development of the upstream areas to a certain extent, and the per capita GDP and regional GDP of the relevant regions had declined. However, it had no significant effect on the economic development of the downstream areas. These conclusions were still valid after several robustness tests. Moreover, the negative impact of pilot policy on economic development of the upstream areas increased firstly and then decreased. Additionally, the driving mechanism analysis showed that the number of "industrial enterprises above designated size" decreased significantly in the five pilot counties, and revealed that "enterprise exit" was an important reason for the negative impact of Xin'an pilot policy on the economic development of the upstream regions. This study could provide reference for the formulation and implementation of the benefit allocation mechanism of trans-regional water resources protection.
2021 Vol. 41 (4): 1940-1948 [Abstract] ( 322 ) [HTML 1KB] [ PDF 461KB] ( 1639 )
1949 Study of atmospheric trace elements emission standards for coal-fired power plants in China
WANG Shu-min, BAI Xiao-xuan, SONG Chang, ZHANG Yi, GU Yong-zheng, GUO Zhi-hui, WU Bo-bo, YU Xue-hai, DUAN Lei, TIAN He-zhong
In this study, the trace elements emission standards of coal-fired power plants (CFPPs) between China and developed countries and the emission status in Chinese CFPPs were systematically evaluated to explore the feasibility and recommendations for establishing standards in the future. Results indicated that fewer species of trace element pollutants were currently restricted in China, and the existing emission limit for the single element (mercury and its compounds, 30μg/m3) was relatively laxer compared with CFPPs in developed countries. Moreover, the stack concentration of mercury in most plants was lower than 10~15μg/m3, indicating the current emission standard has failed to play a viable role in limiting the atmospheric mercury emission from Chinese CFPPs. Therefore, we suggested that the current atmospheric mercury emission limit for Chinese CFPPs should be revised and emission limits for other toxic trace elements could be introduced when revised emission standards for coal-fired power plants in the future, to better protect the ecosystem and human health and promote the successful fulfil of the Minamata Convention on Mercury.
2021 Vol. 41 (4): 1949-1958 [Abstract] ( 250 ) [HTML 1KB] [ PDF 892KB] ( 1239 )
1959 Socioeconomic factors influencing atmospheric mercury emission changes in China
WU Xiao-hui, XU Li-xiao, QI Jian-chuan, LIANG Sai, WANG Shu-xiao
Atmospheric mercury emissions in China during 1997~2017 were calculated by the input-output model from the production and final demand perspectives. Combined with structural decomposition analysis, the relative contributions of socioeconomic factors to atmospheric mercury emissions were also analyzed. The results showed that two big production side sectors discharging large amounts of atmospheric mercury emissions were cement and cement asbestos (135t) and nonferrous metal smelting and processing (86t). On the consumption side, the two major sectors with large atmospheric mercury emissions were mainly construction (219t) and motor vehicles (16t). The relative contributions of socioeconomic factors were different across emission sources and sectors. The increase in per capita final demand volume was the dominant factor driving atmospheric mercury emissions, where nonferrous metal smelting and processing, electricity and heat, cement and cement asbestos were the main sectors responsible for the increasing emissions. The decline in mercury emission intensity was the main factor mitigating atmospheric mercury emissions, where nonferrous metal smelting and processing, electricity and heat, cement and cement asbestos were also the main sectors for the reductions. In this period, the changes in the production structure, final demand sectoral structure, and final demand category structure had led to a slight increase in atmospheric mercury emissions. However, in the same period, the number of emission sources and sectors with a decrease in mercury emissions, due to changes in these three structural factors, had also increased. Based on these results, several relevant policy recommendations were proposed from the perspectives of production-chain-wide control and socioeconomic structure optimization.
2021 Vol. 41 (4): 1959-1969 [Abstract] ( 382 ) [HTML 1KB] [ PDF 1785KB] ( 1330 )
1970 The impact of innovative agglomeration spatial distribution modes on haze pollution
ZHONG Shun-chang, YAN Cheng-li, REN Jiao, SHAO Jia-Hui
In order to compare and analyze the influencing mechanism of monocentricity and polycentriciy distribution patterns on haze pollution, a provincial panel data model and an intermediary effect model were constructed for empirical test. The results showed that the innovation agglomeration reduced haze pollution through scale effects, however, the impact of innovative agglomeration spatial distribution modes on haze pollution was heterogeneous. Specifically, the monocentricity mode induced haze pollution, and there was an paradox of the environmental effect of innovation agglomeration. However, the polycentricity mode had an improvement effect on haze pollution. With the increase of the polycentricity of innovation agglomeration, its effect on haze reduction was enhanced, but with marginal diminishing characteristics. Energy utilization efficiency was one of the important channels for the spatial distribution modes of innovation agglomeration exerting influences on the haze pollution. Based on the findings above, this paper suggested that the provincial polycentric collaborative innovation development strategy was needed to be implemented, and the provincial polycentric innovation network organization system was imperative to be constructed by government, so as to form a polycentric synergistically governance mechanism for haze pollution, and to solve the paradox of environmental effect of innovation agglomeration.
2021 Vol. 41 (4): 1970-1984 [Abstract] ( 248 ) [HTML 1KB] [ PDF 1115KB] ( 1088 )
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