As the main precursor of the smog and acid rain in the atmosphere, SO₂ plays an important role to the near-surface O₃ pollution. Meanwhile, SO₂ also affects the global and local atmospheric circulations because its strong absorption on the ultraviolet influences the solar radiation dramatically. Therefore, it is beneficial to study the temporal and spatial distributions of SO₂ and their variations. In this paper, the spatial and temporal distributing features of SO₂ at global atmospheric boundary layer were studied by the remote sensing data from 2005 to 2017. A spatial heterogeneity was observed from the analyzing results. Specifically, the high columns of SO₂mainly concentrated on the volcanic eruption areas as a natural source and on the industrial emission areas as an anthropogenic source. The first, second and third grades of SO₂ columns distributed zonally in the whole world. It was evidently affected by the human emissions in the Northern Hemisphere that the boundary line of SO₂ column grades protruded southward on the land and sunk northward on the ocean. In the Southern Hemisphere, on the contrary, the boundary line paralleled to the latitude. From 2005 to 2017, the annual average of SO₂ unit grid values at the global atmospheric boundary layer was increasing before 2011 and then decreasing. During this period of time, the volcanic eruptions led to obvious variations in the summer of 2008, 2009 and 2011. The alteration of SO₂ at the atmospheric boundary layer was associated with the movement of the direct solar radiation point within each year. From 2005 to 2014, the latitudinal axis of symmetry of the first grade SO₂ columns matched with the 15^th day's solar declination of each month, except October, November, and December.

According to the VOCs calculating method, a vehicle emission inventory of VOCs had been established based on a daily average monitoring dataset of 4346 traffic stations in national trunk highways (NTHs). Ozone formation potential (OFP) of VOCs was estimated by the maximum incremental reactivity (MIR). A dynamic segmentation technology was used to the NTHs and then the intensity of OFP was calculated by kernel density analysis method to analyze its spatial distribution. The results show that annual emission of VOCs of passenger car was the largest one with its percentage up to 70.50%. Guangdong Province account for the most in all provinces and was 10.7%. G15 accounted for 5.4% and was the largest among all the NTHs. Olefins and aromatic hydrocarbons were the main contributors of OFP, the top ten key organic pollutants account for 67.29%. The intensity of daily average OFP of both freight and passenger vehicles varied largely in different highways and were affected by the traffic flow. Beijing and Tianjin showed a cluster concentration and took a belt distribution in Shijiazhuang. A meniscus distribution was along Jinan, Zibo, Weifang and Qingdao. Nanjing-Suzhou-Shanghai-and Hangzhou also showed a cluster distribution and converged in Shanghai. Shenzhen was a centre around Bay area of Yue-Gang-Ao. Shenyang, Zhengzhou, Xi'an, Wuhan, Chongqing and other hub cities showed a secondary intensity agglomerations.

Atmospheric environmental capacity is an important index to support air quality management and the total quantity control of air pollutant emissions. The air quality model WRF-Chem was used to simulate and estimate the atmospheric environmental capacity under the background of Asian monsoon climate change in Mengzi over the Yunnan Plateau. 2005 and 2015 respectively was chosen as the strong and weak monsoon years according to the normalized South-Asian Monsoon Index. Concentrations of major atmospheric pollutants at all seasons (represented by January, April, July and October respectively) of 2015 and summer (represented by July) of 2005 were simulated, the atmospheric environmental capacities of CO, NO₂, SO₂, PM_2.5 and PM₁₀ in Mengzi were estimated with 120.31、1.127、1.875、1.267、1.688(×10⁴t/a), respectively. The atmospheric environmental capacity of major air pollutants in winter was the smallest; and in spring was the largest excepting PM₁₀, and the PM_2.5 emissions in winter reached saturation. Compared with the 2015 summer with weak monsoon, the atmospheric environmental capacities of CO, NO₂, SO₂, PM_2.5 and PM₁₀ increased respectively by 4.81%, 3.86%, 12.6%, 18.4% and 8.7% in 2005 summer with strong monsoon, and the PM_2.5 increased most. The interannual variation of the Asian monsoon plays an important role in regulating the air quality and atmospheric environmental capacity of the Yunnan plateau.

The spatial distribution of dust frequency was extracted from MODIS L1B data of 460 days in spring from 2014~2018 in the Northwest of China by using brightness temperature difference (BTD) algorithm and dust source was identified by combining with the geomorphological type and the content of fine particles in surface sediments. The results showed that dust activity in the region is characterized as two regions and three belts in which the two regions are Tarim Basin in Xinjiang Autonomous Region and Gobi Desert of southern Mongolian plateau and the three belts are desert oasis in southeastern margin of Taklimakan Desert (270~287 times), northern margin of Kumutag Desert (240~250 times), and desert oasis in the northwestern margin of Badain Jaran Desert (240~250 times). The region with high frequency of moderate and severe dust activities is mainly located in desert oasis of the northwest margin of Taklimakan. The dust source is mainly located in the transit zones from Alluvial fan, via Gobi, to the edge of Desert filled with dry riverbed, dry lake, and degraded oasis. The surface in the region covers fine sand particles and provide rich sand material for the high-frequent and high-concentrated sand and dust. The fine particles are easy to release to atmosphere and diffuse to the surrounding region through the local dust circulation process.

Eleven representative urban areas in the Xinjiang region were selected for classification based on Aqua-MODIS C006 aerosol daily product data from 2006 to 2017, and the variations in AOD were studied for the 11cities in Xinjiang. The results showed that the AOD decreased in different degrees except in Urumqi during 2006 to 2017. On the contrary, AOD for the Urumqi area varied in a small increase during the same period. The average annual decline of AOD in the northern Xinjiang cities was relatively small, the AOD for Turpan decreased by 0.13 during the 12 years, which was the largest decline in the Hami and Yanqi urban agglomerations at the same latitude. The average annual decline of AOD in the southern Xinjiang cities was the most significant, the AODs decreased by 0.18, 0.16, 0.16 and 0.09 in Aksu, Kashgar, Hotan and Ruoqiang, respectively. The peak of the spatial distribution of AOD was in the southern Xinjiang, with an annual average higher than 0.50, and the annual average values of AOD in the northern and eastern Xinjiang were maintained at about 0.20 to 0.22. Meanwhile, AOD had seasonal variation characteristics, with a peak in spring, followed by summer, autumn and winter. In addition, the AOD decreased in different degrees in the Xinjiang region in the past 12 years, the source area of dust aerosols in the southern Xinjiang was the main area of AOD decline, and the reduction area showed a belt shape along the Kunlun Mountains from south to north.

Based on the OMAERUV data daily product, the spatial and temporal distribution of the ultraviolet aerosol index (UVAI) in Gansu Province from 2008 to 2017 was analyzed, and the related factors were discussed. The results showed that the spatial pattern of UVAI nearly 10 years in the province gradually decreased from northwest to southeast region. The high value area of UVAI distributed in Jiuquan City and its neighboring areas, which was the center of absorbent aerosol pollution. The stability of UVAI in Gansu Province gradually decreased from northeast to southwest region. The monthly average value of UVAI showed an obvious regularity, and the monthly change of UVAI showed a "V" pattern every year; the UVAI level of four seasons was:winter > spring > autumn > summer, the seasons were basically synchronized, the UVAI of the four seasons had risen gradually during past ten years, and the sources of the absorbed aerosol dominated in four seasons were different. The analysis of air quality level Based on UVAI of PM_2.5 indicated that the air quality in Gansu Province was mainly good; From the analysis of correlation between meteorological factors and UVAI, precipitation, temperature showed a significant positive correlation to UVAI, and the wind direction also had an important impact on its spatial distribution; the areas where the main distribution of vegetation coverage and UVAI was positively correlated distributed in the northwestern of Gansu Province and the center of Wuwei City, the areas where the main distribution of vegetation coverage and UVAI was negatively correlated distributed in Tianshui and Longnan in the south of Gansu Province, which had a higher vegetation coverage.From the point of the correlation between human activity factors and UVAI, regional GDP, industrial output value and UVAI had a significant positive correlation, especially the secondary industry and UVAI had the highest relevance; UVAI had a strong positive correlation with car ownership, total energy consumption and population density, which indicated that automobile exhaust, industrial emissions and construction dust were important source of absorbing aerosol. Based on the spatial and temporal distribution characteristics of UVAI and the analysis of natural and human activities in Gansu Province, some suggestions of reducing the intensity of human activities were proposed.

By utilizing the hourly observational data of "dry" aerosol scattering coefficient and "dry" aerosol absorption coefficient, as well as the coincidental data obtained from GRIMM180 in Chengdu during December 2017, "dry" aerosol equivalent complex refractive index at 550nm, including both real part and imaginary part as a whole, were integrally retrieved by immune evolutionary algorithm, and then their characteristics in winter were analyzsed. The results showed that:Real part and imaginary part of "dry" aerosol equivalent refractive indices were (1.547±0.0552) and (0.0197±0.00604) respectively. The diurnal variations of real part and imaginary part of "dry" aerosol equivalent complex refractive index generally depicted a consistent pattern, with the feature of "single valley", and the valley occurred between 15:00 and 18:00. To the diurnal time scale, real part of "dry" aerosol equivalent refractive index and mass concentration statistically produced cooperative effect on the evolution of "dry" aerosol scattering extinction, and there existed similar influence of imaginary part of "dry" aerosol equivalent refractive index and mass concentration on the evolution of "dry" aerosol absorption extinction. Imaginary part of "dry" aerosol equivalent refractive index could well symbolize the "dry" aerosol absorption extinction capacity per mass concentration.

The precipitation conductivity, pH value and water-soluble ion concentration of precipitation in Chongqing from 2002 to 2016 were studied based on the wet deposition data from Acid Deposition Monitoring Network in East Asia (EANET). The acidification of rainfall at rural site of Chongqing was serious, while precipitation pollution at urban site was serious. Average concentrations of water-soluble ions in precipitation at urban and rural sites reached 627.00μeq/L and 480.14μeq/L, respectively. The average concentrations of SO₄^2-, NH₄⁺ and Ca²⁺ at urban site was 1.21~1.47times higher than those at rural site. The ratio of SO₄^2- to NO₃^- indicated that the type of precipitation in Chongqing changed from sulfuric acid type to sulfuric acid-nitric acid mixed type. The main ion deposition at urban site was relatively high and about 1.14times that of the rural site. The inorganic nitrogen deposition in precipitation varied from 17.59kg/(hm²·a) to 47.31kg/(hm²·a) and was dominated by ammonium-nitrogen (NH₄⁺-N). The average deposition of NH₄⁺-N was about twice as much as that of NO₃^--N, indicating serious NH₃/NH₄⁺-N pollution in Chongqing.

PM_2.5 samples were collected from three monitoring sites including Handan Iron & Steel Group (Han Gang), Environmental Monitoring Center in Handan (Huan Bao Ju) and Hebei University of Engineering (Kuang Yuan) in Handan urban area for typical months of four seasons. The water-soluble ions, elements and carbonaceous components were analyzed. A coupled PM_2.5 source apportionment approach, combining emission inventory, receptor model and source-oriented model, was used to identify PM_2.5 source contributions in Handan urban area. The results show that the annual PM_2.5 concentration in Handan urban area was 85.5 μg/m³. The concentration in autumn and winter was significantly higher than other seasons. The PM_2.5 concentration in Han Gang site was slightly higher than that in other sites. The components in PM_2.5 with higher proportion were NO₃^-、SO₄^2-、POA、SOA and NH₄⁺, accounted for 15.7%, 14.5%, 13.2%, 12.2% and 12.4% of the total PM_2.5 concentration,respectively, presenting obvious secondary and organic pollution characteristics. The proportion of secondary and organic components in winter was slightly higher than that in other seasons. The primary organic aerosol (POA) and secondary organic aerosol (SOA) in Huan Bao Ju site was slightly higher than that in other sites. Metallurgy and dust emission were the main sources of PM_2.5 concentration. The contribution was 27.0% and 18.7%, respectively. The contribution ratio of metallurgy in spring and summer was higher than that in other seasons. The contribution ratio in Han Gang site was significantly higher than other sites.

A balloon-borne sampling system for vertical profile of atmospheric CO₂ from the surface to 25 km was developed and field-tested. The sampler is deployed on a stratospheric balloon and relies on passively collecting air using the atmospheric pressure gradient during descent. The atmospheric sample through continuous sampling is measured by a cavity ring-down spectrometer (CRDS) for CO₂ upon recovery. Field campaigns were conducted for the first time on June 13^th and 14^th, 2018 at Xilinhaote Observatory. Measurements of CO₂ mole fractions in laboratory tests indicated a repeatability of 0.08×10^-6 and bias to better than 0.06×10^-6 (1σ) for CO₂ under various conditions. The vertical resolution with our configuration was determined to be 580m up to 10km and better than 2.0km up to 20km respectively according to the molecular diffusion of the sample. The system provides an in situ method of greenhouse gas measurements for validation of satellite data and estimation of regional flux.

Numerical simulations were conducted to investigate the influence of the distance between the upstream building and the downstream building in street canyons (D) on characteristics of air flow and distributions of gaseous pollutants in the canyons. The simulation results showed that the wind velocities in the windward regions in the canyons did not change with the change of D. However, the wind velocities in the leeward and central regions decreased first and then increased with the increase of D, and the minimum value occurred when D=90m. Correspondingly, the peak concentration of the pollutant in the canyons appeared at the same D, which indicated the most unfavorable value of D existed. In urban planning, it should be avoided as far as possible. When D was more than 90m, the larger the D was, the lower the pollutant concentration would be. When D was less than 90m, the smaller the D was, the lower the concentration would be, which could be benefit for both land-saving and traffic pollution reduction.

In order to investigate the effect of extracellular polymers (EPS) on the activity of anaerobic ammonium oxidation (ANAMMOX) granular sludge, a certain concentration (30mg/L) of integral extracellular polymers (IN-EPS), loosely bound extracellular polymers (LB-EPS) and tightly bound extracellular polymers (TB-EPS) were added to ANAMMOX granular sludge, respectively. The results indicated that all of the aforementioned EPS could improve the activity of ANAMMOX granular sludge. With regard to the test group including IN-EPS, LB-EPS or TB-EPS, the ammonia nitrogen removal rate of ANAMMOX granular sludge had an increase of 6.68%, 10.5% and 19.29% respectively, while the growth rate of ANAMMOX bacteria increased by 18.25%, 21% and 16.3% respectively. The compositions of three EPSs were basically identical, which is mainly consisted of aromatic proteins and soluble microbial products through three-dimensional fluorescence spectroscopy. And three kinds of acylated homoserine lactones (AHLs) signal molecules in EPSs:C4-HSL, C6-HSL and C10-HSL were found. Additionally, we discovered that C4-HSL and C6-HSL could improve the activity and growth rate of ANAMMOX particles through adding the above EPSs to ANAMMOX granular sludge. This interpreted why EPS could improve the activity of ANAMMOX granular sludge.

The typical setbacks of the operation of anaerobic ammonium oxidation (Anammox) process were the serious sludge loss and long startup time. Herein, the biofilm formation experiments were designed to select several commercial biocarriers with better biofilm performance for ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing bacteria (AnAOB). The results showed that AQ1polyurethane cubic biocarrier was the most suitable biocarrier for AOB to form biofilm. The ammonia oxidation rate of matured biofilm was (0.81±0.08)mg N/(L·h) and the biofilm biomass was (0.87±0.14)mg VSS. Nitrosomonas was dominant species in the activated sludge. For AnAOB (Candidatus Kuenenia), K3 annular biocarrier (made of polyethylene or polypropylene) was the most suitable biocarrier for the biofilm formation. The anaerobic ammonium oxidation rate of matured biofilm could reach (3.27±0.10)mg N/(L·h), and the biofilm biomass was (2.74±0.40)mg VSS. The biofilm formation of AnAOB on the K3 biocarrier was better than AOB. The reason was that the content of extracellular polymeric substances secreted by AnAOB was higher than that of AOB, and extracellular polymeric substances play an important role in biofilm formation.

Bath experimrnts were conducted to study the degradation characteristics and microbial community of quinoline and indoles co-substrate under anaerobic denitrification and methanogenesis conditions, which were known as typical N-heterocyclic compounds. The results showed that the presence of quinolone could inhibit the degradation of indole, and the inhibition effect was enhanced with the increase of quinoline concentration; the presence of indole could promote the degradation of quinoline, but the high concentration of indole (150mg/L) inhibited the degradation of quinolone; the kinetics of quinoline and indole was followed the zero-order kinetics model; through GC-MS analyses, the intermediate metabolites of quinoline were 2-hydroxyquinoline and 2,8-dihydroxyquinoline; and metabolites of indole were oxindole and isatin. The high-throughput sequencing technology was used to analyze the microbial community structure, and results indicated that the functional bacterial were enriched in the anaerobic denitrification and methanogenesis system. The bacterial phylum was Proteobacteria, the dominant classes were Gammaproteobacteria and Betaproteobacteria, and the dominant genera were Acinetobacter, Candidimonas, Azospira, and Desulfomicrobium.

Dark fermentation for H₂ production was a promising bioenergy, as it could use straw and/or wastewater containing high organics as raw materials. The accumulated volatile fatty acids (VFAs), which were produced during the process of hydrogen fermentation, significantly inhibit the process of hydrogen production in the dark fermentation. Herein, bioelectrochemical system (BES) was used to treat the effluent of dark fermentation. A microbial electrolysis cell (MEC) was firstly used to treat the effluents of dark fermentation. Accompanied with hydrogen production in MEC, the pH value of the effluents increased from 4.5 to 8.7. Then the near-neutral effluents were used for methane production using a single-chamber microbial electrosynthesis system (MES), in which methanogens acted as biocatalysts to reduce CO₂ to CH₄. The results showed that the chemical oxygen demand (COD) removal efficiency and CH₄ production rate of single-chamber MES were 89% and 4.5mmol/(L×d), respectively, significantly higher than that without any treatment.

Aluminum-carbon micro electrolysis was adopted to study the removal efficiency of Cr(Ⅵ) in heavy metal wastewater by taking aluminum scraps and activated carbon particles as the experimental materials. The influences of settling time, the mass ratio of aluminum and carbon(Al/C mass ratio), initial pH, oscillation speed and oscillation time on Cr(Ⅵ) removal efficiency were investigated. Scanning Electron Microscope (SEM), Specific Surface Area Analyzer(BET), Energy Dispersive X-ray Spectrometer(EDS) and X-ray Photoelectron Spectroscopy (XPS) were used to analyze the variations in surface physical morphology and composition of aluminum scraps-activated carbon particles before and after the operations, and to study the mechanism of aluminum-carbon micro electrolysis The results showed that the influences factors on Cr(Ⅵ) removal efficiency could be listed from the highest to the lowest as follows:initial pH, the mass ratio of aluminum and carbon, oscillation speed and oscillation time. The removal efficiency of Cr(Ⅵ) reached the highest value of 95.40% under the optimum conditions when the Al/C mass ratio was 2:1, initial pH was 5, oscillation speed was 150r/min, and oscillation time was 40min. It was proved that the removal efficiency of Cr(Ⅵ) could be greatly improved by using aluminium-carbon micro electrolysis instead of direct reduction of pure aluminium or iron-carbon micro electrolysis. The main removal mechanism of Cr(Ⅵ) was the reduction of Cr(Ⅵ) to Cr (III) by carbon cathode during the micro electrolysis process.

Degradation of carbamazepine (CBZ) by two different forms of MnO₂ (δ-MnO₂ and colloidal MnO₂) was studied and compared. The intermediate products in CBZ oxidation at different pH by δ-MnO₂ or colloidal MnO₂ were analysed via LC/MS. Results demonstrated that 1mg/L of CBZ could be completely removed by both δ-MnO₂ and colloidal MnO₂ within 2 hours. Comparing to δ-MnO₂, colloidal MnO₂ was less affected by pH and had better removal of CBZ per unit mass Mn. In total, 7 and 4 kinds of intermediate products were detected in the process of CBZ oxidation by δ-MnO₂ and colloidal MnO₂, respectively. That was because colloidal MnO₂ had stronger oxidizing power, and could omit several oxidation steps producing various intermediates. As a result, CBZ oxidation by colloidal MnO₂ was via a more concise pathway.

A denitrifying phosphorus removal system combining anaerobic/anoxic/oxic (A²/O) with biological contact oxidation process (BCO) was used to treat synthetic wastewater. By adjusting the ratio of sodium acetate to sodium propionate (sodium acetate:sodium propionate=1:0,2:1,1:1,1:2 and 0:1), the organic matter removal and denitrifying phosphorus removal characteristics of the system were investigated. The results showed that the ratio of sodium acetate to sodium propionate revealed a negligible effect on organic matter and NH₄⁺-N removals, but the influences on organic consumption in the anaerobic stage, total nitrogen removal as well as the phosphorus release and absorption were obvious. The operation parameters of the system need to be further optimized due to the low phosphorus removal of 50.3%~56.8%. When the sodium acetate/sodium propionate was 1:1, the organic matter consumption in the anaerobic section was the highest, accounting for 61.2% of the total organic matter input, with the maximum anaerobic phosphorus releaseamount(23.2mg/L) and anoxic phosphorus uptake rate (71.4%). However, the TN removal increased with the addition of sodium propionate. High-throughput sequencing results showed that the microbial diversity in the A²/O reactor was lower, while the mixed carbon source sludge was more abundant than that of the single carbon source. Particularly, the amount of Chloroflexi and Saccharibacteria reduced while the Proteobacteria and Bacteroidetes increased in the domesticated sludge. The total proportion of nitrifying bacteria in the BCO reactor was 2.1%~31.4%, and the ammonia oxidizing bacteria (AOB) was dominate which favoured the realization of short-cut nitrification.

The aims of this study were to explore spatiotemporal differences in water quality of 4 main rivers (Taige River, Wuyi River, Wujin River and Yongan River) in Wunan District based on 2006~2018 water quality monitoring data, to identify the contributions of different activities on water quality parameters, to evaluate the effects of treatment projects on water quality, and to conduct seasonal and correlation analysis for the most heavily polluted river (i.e., Yongan River). The results showed that water quality of 4 rivers improved from 2006 to 2018, with the modified Nemerow index declining by 36.2%, 31.5%, 56.4% and 48.7%. Water quality of Yongan River deteriorated in 2017 due to dredging activities. The ammonia nitrogen (NH₃-N) concentration, total nitrogen (TN) concentration and permanganate index significantly decreased year by year (P<0.05), but the total phosphorus (TP) concentrations fluctuated across the same period. The correlation analysis indicated that NH₃-N, TN and permanganate index may stem from the same sources. NH₃-N and TN exhibited an obvious seasonal variation, but no clear trend was observed for TP and permanganate index. Overall, increased urbanization, decreased traditional industry, and decreased agricultural activity had positive effects on improving water quality in Wunan District.

Thirty-three water sampling sites in Heihe River of the upper and middle reachers were set to characterize its water quality with spatiotemporal distribution. Water sampling trips were conducted in May (wet period), August (flow period), December (dry period) of 2017. Spatial and seasonal variations of water quality were analyzed by using the multivariate statistical methods and water quality were assessed by employing the comprehensive water quality identification index. The results indicated that the main types of water quality in the region were Class II and Class III, it also had a certain space-time differentiation. In temporal terms, the order of pollution was dry period > wet period > flow period; the spatial pollution situation was the upper tributary > the lower main stream > the middle reaches. According to landscape difference, the sampling sites were divided into 4groups:grazing and industrial area (Group A), reservoir area (Group B), agriculture and urban area (Group C). The results of factor analysis and APCS-MLR show that NH3-N, BOD5 and CODMn were typical pollutants in this region, and the pollution sources of group A were mainly from organic matter, followed by nutrients; the water quality of group B was mainly polluted by the accumulation of organic matter and nutrients, while the influence of natural factors were relatively weak; group C was mainly polluted by biochemistry, followed by non-point source nutrients pollution. The results show that human activities were still the main factors affecting the deterioration of water quality. Although the interception effect of dams could improve the quality of discharge water, the pollutants accumulated in the reservoir area all the year round have the potential risk of secondary pollution with the change of environment, such as the activation and release of nutrients in sediments.

Eight metabolites of 5 PAEs were determined in 141 drinking source water samples from 90 drinking water supply plants of 23 cities in China using UPLC-MS/MS method. MPAEs were detected in all drinking source water samples, and the average concentration of mono-n-butyl phthalate (MnBP) was the highest (74.7ng/L) among target MPAEs. The concentrations of monoethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP) and MnBP in source water were significantly correlated with those of diethyl phthalate (DEP), di-iso-butyl phthalate (DiBP) and di-n-butyl phthalate (DnBP), respectively, suggesting common source for MPAEs and their corresponding PAEs. The percentage of secondary metabolites relative to∑DEHP (total concentrations of primary and secondary metabolites of DEHP) (4.0% ±5.6%) in source water was comparable to that from the microbiological degradation of DEHP in aqueous environment, suggesting that these metabolites in drinking source water were mainly from the microbiological degradation of PAEs in aqueous environment.

In order to optimize the stabilization of washed municipal solid waste incineration (MSWI) fly ash (FA) by calcination, the influence of the heating method (continued-heating, multistep-heating) and atmosphere conditions on the evolution of crystal composition in washed FA was discussed. Three kinds of FA (RFA-II#、CaFA-II# and NaFA-II#) were tested and compared. RFA was the boiler fly ash (RFA), CaFA and NaFA were FA resulted from discharged gas neutralized by CaO/Ca(OH)₂ and NaHCO₃ respectively, and "II#" means they were dried residues treated by a double washing process. The results indicate that continued-heating was easier to form solid solution to stabilize heavy metals, and 700℃ was the turning point after which the crystal in three FAs changed obviously. The FA neutralized by NaHCO₃ was better to stabilize heavy metals. The simulation results from Factsage were consistent with the XRD results, and it was found that HCl was the first evaporation chloride released from the washed FA during the calcination process.

The printed circuit board (PCB) substrate and surface components of waste mobile phone were separated using biological method in this work. Then the optimum process conditions were explored. Acidithiobacillus ferrooxidans (A.f), was used to remove surface components of PCB. Results showed that a small number of PCB surface components were removed after 3days of bioleaching. After 5days of bioleaching, most of the surface components of PCB could be removed, but still some larger individual components were not removed. After 7days of bioleaching, the surface components of PCB were removed completely. Meanwhile, there were no any components removed from the surface of PCB in the non-innoculation treatment. The results of ICP-OES showed that high concentration of metals ions, which were contained in welding foot of the components, was in the lixivium after 7days of bioleaching. Among them, Ni, Zn and Al were bioleaching and entered into the lixivium with the form of ions. But the elemental Sn in the welding foot was oxidized to an ionic state into the lixivium through the action of A.f, then the Sn hydroxide precipitate was formed rapidly in the lixivium. After the first day of bioleaching, the concentration of Sn ion in the lixivium was decreased rapidly. Through single factor experiments by setting different leaching conditions, the results showed that when the initial pH of the medium was 1.0, the ratio of solid to liquid was 3:50, the inoculum(v/v) was 15%, the temperature was 30℃ and the rotating speed was 125r/min, A.f had the best effect on removing PCB surface components from the PCB. After 7days of bioleaching, the surface components of PCB were removed completely.

On the basis of composition and phase characteristics of copper slag, the reaction behavior of copper slag with arsenic-containing waste acid and the rule of arsenic removal were investigated, and the reaction kinetics of arsenic removal was also elucidated. Under optimal conditions, including a copper slag dosage of 0.2g/mL, a reaction temperature at 23℃, and a reaction time of 24hours, a maximum adsorption capacity of copper slag of 25.89mg/g was achieved, following by an arsenic removal efficiency of 99.56%. The leaching toxicity of arsenic-fixed copper slag was lower than 5mg/L that is the standard threshold value of hazardous waste. The arsenic-fixed copper slag could be classified as a general solid waste. The kinetic studies revealed that the arsenic adsorption on the copper slag was described by a pseudo-second-order kinetic equation. The process of arsenic removal was limited by the release rate of iron ion. Arsenic was removed via the ion exchange adsorption and the chemical precipitation, which were also beneficial to the arsenic stabilization. A large number of iron ions were released during the solid-liquid reaction between copper slag and waste acid, which could precipitate arsenic via the ion exchange adsorption and the chemical precipitation, forming relative stable arsenates and their derivatives for the arsenic removal. The copper slag exhibits a superior performance for the arsenic removal from waste acid and provides a high-efficient and low-cost method for the disposal of waste acid from heavy non-ferrous smelting industry.

The Dianchi peat soil was collected from Dianchi Lake in Kunming, Yunnan, China. The peat soil was treated by different concentrations of NaOH solutions, and effect of alkali solution for the properties of peat soil and the sorption characteristics of contaminants was evaluated. Adsorption mechanisms of two antibiotics, sulfamethoxazole (SMX), carbamazepine (CBZ), and bisphenol A (BPA) on peat soils before/after NaOH treated were discussed. Effects of the properties for contaminants as well as the peat soils on their sorption characteristics were investigated. Adsorption isotherms for SMX, CBZ and BPA were well fitted by the Freundlich model, and the fitting results showed that the Freundlich nonlinearity factor n values of BPA were the lowest among these three contaminants, which may be due to its asymmetric structural characteristics. As the concentration of NaOH increased, adsorption of these three contaminants on peat soils was BPA > CBZ > SMX. BPA has two phenolic hydroxyl groups and thus it could interact with peat soils by polar interaction, this may result in the highest sorption of it on peat soils. Adsorption of CBZ was higher than that of SMX was due to the hydrophobic interactions between CBZ/SMX and peat soils. Adsorption of SMX, CBZ and BPA on peat soils treated by NaOH solutions was not increased, this suggested that the sorption processes and mechanisms of ionic compounds on peat soils were complex, many factors such as functional groups and solubility of contaminants, the contents of organic carbon and functional groups of peat soils affected the sorption. The butterfly structure and two hydroxyl groups of BPA may lead to its specific adsorption on peat soil, which resulted in the highest adsorption coefficient. The organic carbon content of peat soil increased but the specific surface area may decrease after NaOH treated, and thus reducing the adsorption of these three contaminants. Therefore, adsorption of these three ionic compounds on the peat soils was affected by various factors, including the functional groups and solubility of adsorbates, the organic carbon content and functional groups of peat soils in this study.

The electro-Fenton (EF) process combined with bioremediation (BIO) process was established for pyrene (Pyr) contaminated soil. Two factors including degradation characteristics as well as environmental parameters were compared between EF and BIO processes. Optimal process order was determined by a series batch tests of parameters, such as the effects of removal rate, degradation efficiency, concentration of ·OH radical, biomass, and the pH value. The results showed EF process followed by BIO process was the optimum process order, the removal efficiency of Pyr was almost 50% higher than each single process. After 72h of reaction time, Pyr removal efficiency of the EF-BIO combined treatment process was still high of 91.02%.

Modification of montmorillonite with selenium was carried out with sodium selenite, montmorillonite and other materials, and the passivation agent of mercury was prepared by combining selenium with modified montmorillonite, so as to reduce the enrichment of mercury and methyl mercury in rice. In this paper, selenide repairing agent was mixed with the contaminated soil for soaking soil test and pot experiment, the THg and MeHg in soil and rice were analyzed, effect of different selenide repairing agents on the control of mercury in polluted soil was discussed, and the best repair agent was selected.The results showed that all four kinds of repairing agents had obvious passivation and control effect on mercury in contaminated soil, which could significantly reduce the exchangeable mercury and methylmercury in soil and reduce the content of THg and MeHg in rice. After the montmorillonoid was modified by selenium in different ways, the structural energy of montmorillonite was optimized, the adsorption capacity was increased, and the selenium can be stabilized on montmorillonite to achieve better passivation effect. The reduction rate of the modified montmorillonite with selenide chitosan, the modified montmorillonite with sodium selenite, the modified montmorillonite with selenide cellulose and the modified montmorillonite, with selenium powder to rice THg was 81.86%, 79.74%, 65.69% and 61.78%, respectively, and the reduction rate of these repairing agents to rice MeHg was 89.62%, 83.91%, 72.93% and 63.01%, respectively. Comparatively speaking, the remedial effect of the modified montmorillonite with sodium selenite was slightly lower than that of the modified montmorillonite with selenide chitosan, but its modification method is simple and low cost, which is more favorable to the popularization and application of repairing agent.

In order to study the adsorption behavior and mechanism of veterinary antibiotics on the loess of Northwest China, ciprofloxacin was selected as the target pollutant, and batch equilibrium method was conducted to investigate its adsorption kinetics, adsorption thermodynamics, and influencing fators, such as pH values and particle sizes, on the adsorption process. Results showed that the adsorption of ciprofloxacin on loess can be divided into two stages:fast adsorption stage (0~6h) and slow adsorption stage (6~10h), and adsorption equilibrium was reached after 10 hours. The adsorption processes fitted well with the pseudo-second-order adsorption kinetics model, and the adsorption rate was controlled by both the internal diffusion of particles and the external diffusion of liquid membrane. The adsorption thermodynamics process was in accordance with the Freundlich model, and the isotherm adsorption was belonged to L-type, which means the adsorption behaviour was affected by the interaction of solute and water molecules in solution. The changes of Enthalpy (ΔH^θ), Entropy (ΔS^θ) and Gibbs free energy (ΔG^θ) were all less than 0, indicated that the adsorption was a spontaneous exothermic reaction with a decrease of chaotic degree. The maximum adsorption amount of ciprofloxacin on loess was obtained at 5 of pH value, and the adsorption of ciprofloxacin on loess increased with the increase of pH value from 2 to 5. While, the adsorption of ciprofloxacin on loess decreased with the increase of pH value beyond 5, thus, strong acid and alkaline environment were unfavorable to adsorption. The adsorption amount of ciprofloxacin on loess was inversely proportional to the size of loess, and was proportional to the initial concentration as well. According to the experimental results, it was inferred that the adsorption of ciprofloxacin on loess was mainly related to the content of organic matter, and the adsorption mechanism was dominated by the cation exchange of amino groups in ciprofloxacin molecule.

At present, the research on coal pollution emissions has focused on plain areas and has largely ignored mountainous areas.In this paper the mountainous region of Mentougou in Beijing was selected as the research study area as it has 98.5% of its area covered by mountains. A stereo model was constructed to extract a DEM (Digital Elevation Model) using forward-looking and backward-looking ZY-3 images. Classification and a regression tree model (CART) combined with an object-oriented method were used to extract residential areas from GF-2 remote sensing images. Imagery interpretation along with statistical records of the residential areas were used to derive a coefficient of burning coal in a mountainous area. A statistical model was then developed to estimate coal consumption in a mountain area. A literature search helped us to determine emission factors and to estimate the specific emissions of PM₁₀, PM_2.5, NO_x, SO₂, and CO. With the help of remote sensing and a DEM this study demonstrates that the emission of coal-fired pollutants in mountainous areas can be measured efficiently and effectively. Terrain had a significant effect on coal combustion in winter. The derived coefficient of burning in a deep mountainous area was 12.5kg/m² while the shallow mountain area exhibited a value of 9.375kg/m². In the mountain region of Mentougou in 2017 the area of coal-fired residential buildings was 5.68km². The derived coefficient of burning in a deep mountainous area was 12.5kg/m² while the Shallow mountain area exhibited a value of 9.375kg/m². The coal consumption was 0.0652 million tons in the winter, but the emission of air pollutants varied greatly among the towns in the mountainous areas.

Naturally occurring radionuclides (²³⁸U, ²²⁶Ra, ²²⁸Ra, and ⁴⁰K) and artificial radionuclides (¹³⁷Cs and ⁹⁰Sr) were measured using low background β counter system and High Purity Germanium (HPGe) γ spectrometry in 5 genera of coral skeletons collected from 10 locations in the SCS with a spatial coverage of 1500km. Mean activities in modern coral skeletons decreased from ²³⁸U (29.94Bq/kg), ⁴⁰K (11.72Bq/kg), ²²⁸Ra (6.37Bq/kg), ²²⁶Ra (3.16Bq/kg), ⁹⁰Sr (1.21Bq/kg) to ¹³⁷Cs (<0.06Bq/kg). There were no significant trends of activity in relation to coral genera or distance to the land, with an exception of higher²²⁸Ra activity in the fringing reefs than in the atoll reefs. Cross-system comparisons of radioactivity in coral skeletons, sediments nearby or outside coral reefs, and global soil revealed coral reefs as extremely low radiation area on the Earth's surface. It was also found that modern coral skeletons were characterized by two common fingerprints of radionuclides (²²⁶Ra/²³⁸U and ⁹⁰Sr/¹³⁷Cs), including extremely low activity ratio of ²²⁶Ra/²³⁸U (~0.1) and extremely high activity ratio of ⁹⁰Sr/¹³⁷Cs (1000).

In order to study the environmental radiation impact from the coal mining and germanium processing in the germanium ore located in southwestern Yunnan province, an integrated investigation consists of airborne and ground survey had been carried out, while detailed monitoring followed up in the contaminated areas and hot zones. Concentrations of ²³⁸U and ²²⁶Ra in raw materials (coal) and smelting slag exceeded 1Bq/g, while for the intermediate products, reached 10⁴Bq/kg. The radioactivity concentrations of both gross alpha and beta in waste liquid from mining wells and thermal plant were over 1Bq/L. As a result, the environmental radiation levels enhanced. Radioactivity concentrations in some locations of the rivers across the research area were several times higher than the background level. Activity concentrations in crops grown up on the contaminated soils also increased. Indoor radon concentrations in this area were higher than national average level. The average annual effective dose for public exposure was higher than the average level in China.

The phase diagrams of microemulsion systems comprised of Tween 80 as surfactant, pentanol as co-surfactant and three different vegetable oils (soybean oil, palm kernel oil, sunflower oil) as oil phase were constructed for studying the effect of different oils on the properties of microemulsions. Three different vegetable oil-based microemulsions were prepared with different mass ratios of oil/surfactant (O/S), and the solubilization of phenanthrene were compared. The results indicated that different oils had great influence on the phase forming ability and dilution characteristic. The phase forming and dilution abilities of three microemulsions were weakened in the order:palm kernel oil > sunflower oil > soybean oil. The three vegetable oil-based microemulsions with different water contents had similar conductivity trends and showed Newtonian behavior. The solubilization capacities of the prepared microemulsions for phenanthrene increased with the increase of oil content in the system. The soybean-based microemulsion had the lowest solubilization capacity for phenanthrene. The palm kernel oil-based microemulsion had the maximal solubilization capacity for phenanthrene at O/S=0.1, which can up to 2.18g/L.

In order to investigate the effects of a symbiotic bacterium on arsenite (As(III)) accumulation and transformation of C. salina, one symbiotic bacterial strain was isolated from culture medium of C. salina. Antibiotics were added to C. salina to obtain the axenic microalga, and a series of As(III) treatments (0, 75, 150, 300, 750mg/L) were applied to the non-axenic and axenic C. salina. After 7 days, the absorption, adsorption and accumulation of As(III) by C. salina were determined. The As speciation in the culture and algal cells were also analyzed and the rates of As(III) oxidation and removal by non-axenic and axenic C. salina were calculated. At the same time, the symbiotic bacterium was treated with different concentrations of As(III) for 7days, and with 300mg/L As(III) for different time. The oxidation and removal rates of As(III) in the bacterial culture medium were then calculated. Results show that the symbiotic bacterium was identified as Agrobacterium tumefacienss WB-1. Compared with the axenic C. salina, the non-axenic C. salina grew faster with higher tolerance to As(III). Moreover, in the presence of bacterium, As(III) accumulation by C. salina from the culture solution varied from 103.10 to 448.12mg/kg, the oxidation and removal rates of As(III) were 78.93%~96.88% and 18.92%~55.21%, respectively. These values were significantly higher than those of the axenic C. salina, which varied from 11.68 to 91.39mg/kg, 14.46%~26.39% and 12.82%~29.15%, respectively. The As(III) oxidation and removal rates in the non-axenic C. salina culture were also significantly higher than those in the A. tumefaciens cuture (4.51%~30.61% and 1.86%~16.19%, respectively). In addition, a small amounts of As(III) and methylated As were detected in the cells of non-axenic C. salina, while no methylated As was present in the axenic C. salina cells. Symbiotic bacteria promote the enrichment and transformation of As(III) by Chlorella salina.

Ship-based incubation experiments with the addition of nutrients were conducted with surface seawater of the western Pacific Ocean from October 9^th to November 1^th, 2018 to study the impact of the addition of nutrients on phytoplankton biomass and the production of volatile halocarbons (VHCs) by marine phytoplankton. The results showed that the addition of nutrients promoted the increase in the concentration of chlorophyll a (Chl-a) and the emissions of trichloroethane (C₂HCl₃), tetrachloroethylene (C₂Cl₄), chlorodibromomethane (CHBr₂Cl) and bromoform (CHBr₃) by phytoplankton, and the extent of promotion was closely related to the concentrations and ratios of nutrient addition. The maximum Chl-a, C₂HCl₃, and C₂Cl₄ concentrations occurred in the highest concentration of NO₃^--N. The ratio of N/P in accordance with the Redfield ratio could significantly increase CHBr₂ Cl and CHBr₃ concentrations. In addition, the release of four kind of VHCs with added NH₄⁺-N were higher than that of added NO₃^--N.

By the use of three-dimensional excitation emission matrix fluorescence coupled with parallel factor analysis (EEM-PARAFAC) and fluorescence regional integration (FRI) analysis, DOM characteristics of the alpine soil and its changing tendency along an altitudinal gradient from 3200 to 4000m in the western Sichuan province were studied. The results showed that, the DOC concentrations for the alpine soil ranged from 0.47 to 0.81g/kg, showing an increasing trend with the altitude elevation in the same soil layer, and mostly higher DOCs in the topsoil layer than the subsoil. There were always five DOM components in the tested soils, namely, aromatic protein substance I (tyrosine, Peak I), aromatic protein substance II (BOD₅, Peak II), fulvic acid-like (Peak III), soluble microbial byproduct-like (tryptophan, Peak IV) and humic acid-like (Peak V). The fulvic acid-like and humic acid-like species are two major DOM components for the alpine soil. FRI values decreased with the altitude increase. Values of fluorescence characteristic parameters (fluorescence index FI, spontaneous source index BIX, humification index HIX, freshness index β:α) have indicated that, the stability of soil DOM decreases with altitude elevation, while the bioavailability increases with elevation. Therefore, climate warming may lead to increased DOM decomposition and decreased contents in high altitude soils but with an increased stability.

In order to explore their electron exchange capacity, the biochars were prepared from rice straw at different pyrolysis temperatures by limited oxygen heating carbonization, then respectively oxidized with oxygen and potassium ferricyanide oxidants, and reduced with titanium citrate. The electron accepting capacities (EAC) and electron donating capacities (EDC) were quantitatively analyzed. The results show that different pyrolysis temperatures could affect the electronic storage capacity. At 500℃, both EAC and EDC of biochars has been maximized, which were 3.86 and 1.72 mmol/g, respectively. When the pyrolysis temperature increased above 500℃, EAC and EDC both decreased accordingly. This phenomenon is due to the combined action of quinones and phenols functional groups and persistent free radicals in biochar. In addition, titanium citrate and sodium dithionite had different redox potential as reductants, which further confirmed the effect of reductant potential on EAC. The biochars had reversible redox property, the sum of EAC and EDC was approximately equal to the electronic storage capacity of biochar.

Supported bimetallic catalysts Pd-M/CeO₂(M=Fe, Co, Cu) were prepared by the impregnation method and the liquid phase catalytic hydrodechlorination (HDC) of 2,4-dichlorophenoxyacetic acid (2,4-D) was investigated over these catalysts. The catalysts were characterized by inductive coupled plasma optical emission, scanning electron microscope, X-ray photoelectron spectrometer and CO chemisorption. The results showed that cerium oxide could effectively disperse metal particles, and the synergy between metals improved catalytic performance. The Pd-Fe bimetallic catalyst has a relatively excellent catalytic effect. The catalytic activity of Pd-Fe/CeO₂ increased first and then decreased with the increase of Fe loading. In addition, the dechlorination of 2,4-D were proceeded via both the stepwise and concerted pathways.

Microplastics (<5mm) have been detected in freshwater, marine and terrestrial organisms widely, however, no harmonized method is available which limited the scientific value for these existing investigation data. The present study aimed to compare four kinds of digestion solutions for microplastic isolation from fish and clam tissue, and then to evaluate the effects on 10 kinds of typical plastics of four kinds of digestion solutions by using a group of indicators, including morphological observation, quality change, fourier transform infrared spectroscopy and Raman spectroscopy characteristics. The results showed that the digestive efficiencies (%) were followed as the order:10%KOH > RIPA tissue lysate + Proteinase K > Proteinase K > 30%H₂O₂. In addition, PA particle quality increased after treatments, and PU particle colour slight changed after H₂O₂ treatment. Interestingly, the biodegradable plastic particles were soluble in 10% KOH completely. As expected, the infrared spectrum and Raman spectrum of plastic particles did not change before and after treatments, and the plastic particles could be identified based on their spectrum, except for the biodegradable plastic. As a conclusion, the treatment method of 10% KOH at 50℃ and 180r/min incubated for 6hours will be recommended as the preferred method for microplastic isolation from biological tissues.

Sediments were collected from up-to down-stream along a valley bottom on the Loess Plateau. Physicochemical properties of the collected sediments were measured and the characteristics of bacterial and fungal communities in the sediment samples were also determined using the high-throughput sequencing of 16S rRNA gene fragment and ITS. From up-to down-stream of the studied valley, the relative abundance of Bacteroidetes and Firmicutes in the collected sediments increased by 6.6% and 10.5% respectively, and the relative abundance of Proteobacteria decreased by 15.1%. The relative abundance of Basidiomycota increased by 7.7%, while the relative abundance of Ascomycota decreased by 30.2%. The bacterial richness (Chao1index) and diversity (Shannon index) were negatively correlated with sediment clay content (P<0.05), while the correlations between clay content and fungal were not significant. The richness and diversity of bacterial and fungal communities were also correlated with sediment SOC and Olsen-P (P<0.05). Therefore, sediment compositions and nutrient content appeared to be a crucial factor influencing the spatial variability of sediment microbial communities and diversity.

In order to mitigate of the sever soil erosion and degradation in ecological environment in the rare earth mining area, a vegetation restoration project in the abandoned land of rare earth mining area in Changting, Fujian was implemented several years ago. Physical and chemical properties and microorganisms' composition of soil in the heap leaching of abandoned land of rare earth mining, Changting after different years of vegetation restoration were analyzed. The results showed that physical and chemical properties of soil after three and four years of vegetation restoration were significantly higher than those in the untreated abandoned land (without restoration) but lower than the unmined area (P<0.05). After 4years of vegetation restoration, the physical and chemical properties of soil in the abandoned land of rare earth mining area, Changting showed a downward trend, but still significantly higher than that of untreated abandoned land (P<0.05). Differences were identified in the abundance and diversity of soil bacteria of abandoned land of rare earth mining between different years of vegetation restoration. The diversity and abundance of soil bacteria decreased with the years of vegetation restoration,. However, the relative abundance of some special bacterial groups such as Gamma proteobacteria, Alphaproteobacteria, Acidobacteria and Cyanobacteria significantly increased in the stands of different years of vegetation restoration. The relative abundance of Cyanobacteria, a type of bacteria of nitrogen fixing, decreased along with the process of vegetation recovery. Euryarchaeota only existed in the unmined land, and Acidobacteria increased with the increase of years of vegetation restoration. The dominant flora in soil, Euryarchaeota, Firmicutes, Proteobacteria, Methanobacterium and Ralstonia, were positively correlated with soil pH, total phosphorus, total potassium and available phosphorus. The diversity and relative abundance of bacterial flora such as Euryarchaeota and Firmicutes were significantly affected by the physical and chemical properties of soil. In conclusion, the artificial prevention and control measures should be taken after 3-4 years of vegetation restoration in the heap leaching land of ion-type rare earth mining area to mitigate the degradation.

A denitrifying strain ZY04 with high nitrite-accumulating rate was isolated and purified from activated sludge in lab-scale A²/O reactor. The strain was characterized and identified as Acinetobacter johnsonii by 16S rDNA phylogenetic analysis. The Logistic model were fitted well to the experimental growth curve of strain ZY04 with the growth equation constants of a=0.6588, b=24.08, k=0.2413. To investigate the partial denitrification performance of strain ZY04, the batch experiments were conducted by fixing the initial concentration at 100mg/L and supplying with different quantities of sodium acetate to control the carbon-nitrogen ratio (TOC/TN) at 3.5, 4.5, 5.5, 6.5. The result showed that ZY04 exhibited the high removal rate of nitrate over 95% under different TOC/TN conditions. The nitrite accumulation rate reached over 70% within 17 hours under the TOC/TN at 3.5 and 4.5, while the rate was over 85% within 11hours under the condition with the TOC/TN at 5.5 and 6.5. the highest nitrite accumulation rate was up to 91% when the TOC/TN was set as 5.5. The results of inhibitory kinetics analysis revealed that three biokinetic models (Aiba, Edwards and Andrews) could well simulate the growth pattern of strain ZY04inhibited by single substrate (nitrate or sodium acetate). In the double-substrate inhibitory model, six models of nine combinations successfully fitted the growth characteristic of strain affected by double substrate of nitrate and sodium acetate. The relevant semi-saturation parameters and substrate inhibition parameters were obtained, and the correlation coefficient (R²) could reach 98%.

A PCL-degrading strain was isolated and identified as Pseudomonas sp. JQ-H3 through morphology observation and phylogenetic analysis. The strain showed the heterotrophic nitrification-aerobic denitrification (HN-AD) ability using PCL as a sole carbon source. About 93.11% of initial ammonium (102.41mg/L) was degraded within 36h with the maximum ammonium removal rate of 5.77mg/(L·h), while approximately 93.93% of initial nitrate (99.01mg/L) was removed within 48h with the maximum ammonium removal rate of 4.12mg/(L·h). 94.03% of PCL film with initial weight of 100mg was decomposed after 60days, and the extracellular lipases activity reached the maximum value of 9.18mU/mL at 30th days. In addition, the expression levels of amoA and nirS genes were promoted in the weak alkaline environment. The successful expression of napA, cnorB and nosZ genes further proved the HN-AD ability of the strain JQ-H3.

An aerobic methane oxidation coupled to denitrification (AME-D) was constructed using a gas circulation sequencing batch biofilm reactor (gcSBBR), and nitrogen loading in influent was observed. It was found that the removal rate of nitrate nitrogen reached 98.93% and the denitrification rate 74.25mg/(L·d) when the nitrogen load was 0.075kg/(m³·d), and the average daily consumption of methane was 35.91% (at the initial stage:50%). According to scanning electron microscopy (SEM) results, microorganisms in the system were mainly Bacillus brevis (12~18μm), dotted with a few filamentous bacteria (150~200μm). The high-throughput sequencing of 16S rRNA indicated that methanotroph were Methylocaldum, Methylomonas, Methylococcus and Methylococcaceae_unclassified, the denitrifying bacteria Denittrasoma, Hydrogenophaga, Azoarcus, Thiobacillus and Rhodobacter, and the main functional bacteria Methylocaldum, Denittrasoma and Hydrogenophaga in this system. Nitrogen was removed by the synergism of aerobic methanotroph and denitrifying bacteria. In addition, a large volume of Methylophilaceae_uncultured (30.4%), which utilized methanol and methylamine as growth substrates, was found.

To assess the toxicological effects of Bisphenol AF (BPAF) on aquatic organisms, the acute toxicity and chronic effects with regards to reproduction, growth and development of Daphnia magna were investigated. The results showed that the LC₅₀ for the 24h and 48h were 9.70mg/L and 5.02mg/L, respectively. BPAF belongs to toxicity class II, according to rules for classification and labelling of chemicals. Clear delay in the sexual maturity time for Daphnia magna exposed to 100 μg/L of BPAF was found. Again, Significant reduction in the total number of eggs per female, the number of brood per female, intrinsic rate of natural increase, the average body length, heart rates and thoracic limbs activity were also found in the Daphnia magna exposed to high concentration of BPAF (100 μg/L). These results provided theoretical basis for acknowledgement of the environmental behaviors of BPAF on aquatic organisms.

The laboratory incubation experiments were conducted to study the toxicity of silver nanoparticles with different particle sizes on Nitrosomonas europaea, and the effects of two sizes of nanosilver (10nm and 50nm) on the bacterial growth, nitrogen transformation, cellular structure, reactive oxygen generation and gene expression were investigated. The results showed that nanosilver inhibited the growth of N. europaea. With the extension of exposure time, the inhibition rate of bacterial growth activity increased and reached to maximum at 4h. In the medium, the transformation rate of NH₄⁺ to NO₂^-was slowed down, and the nitrogen transformation ability by N. europaea was reduced. Scanning electron microscopy (SEM) images showed that nanosilver heavily damaged the cell membrane by causing holes on the surface of bacteria. Transmission electron microscope (TEM) images showed that the nuclear material inside the bacteria was disappeared and the boundary of the cytoplasmic membrane was blurred. Flow cytometry (FCM) was employed to detect that nanosilver could generate intracellular reactive oxygen (ROS) in the cells. qRT-PCR technology was used to determine the expression of amoA, hao and merA of N. europaea after the exposure to nanosilver, and it was found that nanosilver inhibited the expression of the functional genes. In conclusion, nanosilver could interact with cell membrane, generated oxidative stress damage and inhibited the expression of functional genes amoA and merA of N. europaea, which further affected the transformation process of ammonium nitrogen. In addition, the toxicity of nanosilver with small particle size was stronger than that of large particle size.

In order to give full play to the role of leguminous plants in ecological restoration and reconstruction, the root nodule resources of wild Indigofera amblyantha in the rocky desertification region of Guizhou province were investigated. The results showed that the resources of rhizobia and endophytic bacteria of wild Indigofera amblyantha were abundant in southern subtropical seasonal rain forest ecological zone in the dry and hot valley; the symbiotic nodulation rate of wild Indigofera amblyantha was only about 50%, and all the nodules were on the lateral roots and fibrous roots of the host, 0.5~3.0mm in size; 12 rhizobia strains were distributed in 10 species of 6 genera, of which the distribution frequency of Bradyrhizobium was the highest in frequency 41.67%, and the frequencies of occurrence of B.japonicum of Bradyrhizobium and B. bacterium of Burkholderia were the highest in frequency 16.67%; 16 endophytic bacteria strains were distributed in 11 species of 4 genera, of which the distribution frequency of Bacillus was the highest in frequency 43.75%, and the frequency of occurrence of B.megaterium of Bacillus was the highest in frequency 31.25%.

The mixed Chinese fir-broadleaf plantation and pure Chinese fir plantation were selected to survey the species composition, density, vertical distribution characteristics of soil seed bank and their relationships with the aboveground vegetation by field investigation, sampling and indoor seed germination methods. The results showed that the soil seed banks of the mixed plantation was consisted of 30 plant species belonging to 24 family and 30 genus, and the pure plantation was consisted of 24 plant species belonging to 20 family and 24 genus. The seed density of mixed forest and pure plantation were 656.94±89.59seeds/m² and 486.11±77.66seeds/m², respectively. The species composition was dominated by herbaceous plants. Most of seeds in the two stands were distributed in 0~2cm and 2~5cm soil layers, accounting for 69.0%~75.2%. The seeds of tree species were mainly distributed in the litter layer, and the seeds of shrubs, herbs and vines were mainly distributed in the 0~2cm soil layer. The similarity indexes (SI) between soil seed bank and aboveground vegetation of mixed forest and pure plantation were 0.40 and 0.33, respectively, and the overall SI were low. In general, soil seed banks in Chinese fir plantations contain a lot of species and seeds for the underforest vegetation regeneration. The regeneration potential of herb under mixed forest was greater than that of pure plantation. The seed source of Chinese fir was not the main factor of its natural regeneration barrier, and a thick litter layer and low light under the forest may be the main obstacles, but further research is needed.

The Yangtze finless porpoises (Neophocaena asiaeorientalis asiaeorientalis) is a subspecies of finless porpoise and is known to live only in the middle and lower reaches of the Yangtze River and the adjacent Dongting and Poyang Lake. Since the 1990s the population has decreased dramatically due to habitat degradation, by-catch, water pollution and other human activities. The Yangtze finless porpoise was listed as an Endangered species on the IUCN Red List since 1996 and was listed as a top-level protected animal in China since 1989. The Dongting Lake, China's second largest freshwater lake, is located in the northern Hunan Province. The lake is at the south of the middle reach of Yangtze River and is divided into three parts:East Dongting Lake, South Dongting Lake and West Dongting Lake. Dongting Lake is important both at home and abroad due to the aquatic biodiversity, geographical location, and human activities. Dongting Lake has been for hundreds of thousands of years as one of the most important habitats for Yangtze finless porpoise. According to the population assessment by the Ministry of Agriculture and Rural Affairs in 2017, there are approximately 110 individuals (10.87% of the total population) living in Dongting Lake. To assess the population distribution of the finless porpoise and its relationship with fish density, 54 line transects surveys and eight hydroacoustic surveys were conducted in East Dongting Lake covering four hydrological seasons between June 2012 and December 2017. A total of 1110 individuals were observed, and they were primarily distributed in an elongated area approximately 35km long between Xiangyin County and Dongting Bridge. The natural habitat area of finless porpoise estimated by the method of minimum convex polygon (MCP) under the 100%, 95%, 75%, and 50% were 161.3km², 114.3km², 77.0km² and 64.3km² respectively, accounting for 24.2%, 17.1%, 11.5% and 9.6% of the whole finless porpoise protected area. Results of the one-way ANOVA revealed significant differences among observations during different hydrological seasons (P<0.05) and the highest frequency of groups and individuals of finless porpoise were observed (13.92±4.64 groups/survey and 31.92±7.17 ind./survey) during the dry season. The lowest frequency (5.17±1.64 groups/survey and 17.25±7.46 ind./survey) occurred during the wet season. Results of the hydroacoustic surveys showed that the highest fish density was 57.21ind./1000m³ in March 2013. There was a weak negative correlation (R =-0.601, P>0.05) between fish density and water levels in East Dongting Lake. ArcGIS modelling and hydroacoustic technology were combined to analyze the spatial distribution of fish densities, and the results showed that fish mainly distributed in Bianshan-Meitanwan (Area III), Meitanwan-Lujiao Port (Area IV) and Lujiao Port-Nianyukou (Area V) during low water (dry season and late stage of falling season). Fish were more disperse during high water. During low water of Dongting Lake, an uneven distribution of fish was found and significant differences existed between Area III and other areas (P<0.05) with the highest fish density (107.52±17.36 ind./1000m³). Except for the significant differences between Nianyukou-Leishi Port (Area VI) and Chenglingji-Dongting Bridge (Area I), and Area III (P<0.05), there were no significant differences between the other areas (P>0.05). The positive relationship between the number of porpoises and fish density (R²=0.86, P<0.01), analyzed by Pearson correlation, suggests that Yangtze porpoise possesses the behavior to track fish school. Future conservation on the Yangtze finless porpoise could be more effective if special measures are conducted to stop fishing and habitat degradation related to finless porpoises in East Dongting Lake.

Fish species from 28 sampling sites in Muling River basin in May, July and September in 2015 were investigated. 46 fish species belonging to 5 orders, 11 families. 31 species of Cypriniformes contributing 68.89%, followed by Salmoniformes (5species, 11.11%). Siluriformes and Cyprinodontiformes were both included 4 species, while Petromyzoniformes was only 1 species. The annual mean values comprehensive pollution index, Shannon-Wiener, Pielou and Margalef index were 1.10, 1.97, 0.36 and 1.16, respectively. The water quality was moderate or heavy pollution. CCA results showed that water environmental factors influencing fish species varied among three seasons. In spring, main factors were pH, COD_Mn, DO, Fe³⁺, TN and ORP. In summer, vital parameters were Fe³⁺, ORP, TN, pH and TD. In autumn, important variables were WT, NO₂^--N, COND and NO₃^--N.

The feasibility and optimal pathway to achieve China's "double control" targets of carbon intensity and carbon emissions peak from the perspective of energy structure optimization was explored in this paper. Firstly, the Markov chain model and multi-objective optimization model were used to forecast China's energy consumption structure from the perspective of natural evolution, policy constraints and cost constraints. Secondly, three energy structure forecasting scenarios were combined with the three economic development scenarios to obtain prediction results of carbon intensities and carbon emissions under the nine scenarios, and the feasibility of each scenario to achieve the "double control" targets was analyzed. Finally, the multiple attribute decision model was used to select the optimal pathway to achieve the "double control" targets. The results showed that the targeted carbon intensity by 2020 and 2030 can be achieved differently in all scenarios. However, not all scenarios can achieve the carbon emission peak by 2030, and the speed of economic development was inversely proportional to the difficulty of achieving the carbon emission peak. Under the medium-speed economic development, a policy-constrained scenario was the optimal pathway for achieving the "double control" targets. The carbon emission reduction policies played a key role to the realization of the "double control" targets.

Taking Hubei province as an example, a system of environmental performance evaluation indicators was constructed based on the pressure-status-response (PSR) model, and spatial autocorrelation and standard deviation ellipsoid method were used to explore the spatial pattern characteristics and influencing factors of performance indexes in various regions of Hubei Province. The results showed that the environmental performance indexes (EPIs) of all regions investigated in Hubei Province were higher than 60, but those were generally at a medium level and the proportion of good and excellent was low. The regions with higher EPI were mainly located in the western and central parts of Hubei Province. The pressure and status indexes decreased from west to east, and the response indexes in eastern part were higher than those in western and central parts. The status indexes had a significant positive correlation in space, which meant that areas with better (or worse) environmental quality gather in space. The EPIs and the second-level indexes took the northwest-southeast as the layout direction, and the EPI elliptical center of gravity was biased toward the southwest direction compared with the benchmark center of gravity. In addition to being influenced by resource endowments, regional environmental indexes were also significantly related to urbanization rates and population density.

Based on the panel data of 30 provinces in China from 2004 to 2016, the relationship between environmental carrying capacity and cross-regional transfer of heavy chemical enterprises was analyzed. The results showed that (1) the difference in environmental carrying capacity between provinces became an important factor in promoting the cross-regional transfer of heavy chemical enterprises. The decline of environmental carrying capacity could promote the cross-regional transfer of heavy chemical enterprises; (2) The environmental carrying capacity of different regions had a heterogeneous impact on the cross-regional transfer of heavy chemical enterprises. The eastern region had the highest degree of significance, followed by the central region, and the western region had the lowest impact; (3) The environmental carrying capacity of different industries had a heterogeneous impact on the cross-regional transfer of heavy chemical enterprises. In addition to the positive impact of coal mining and washing industry, the environmental carrying capacity of the other seven industries had a negative impact on the cross-regional transfer of heavy chemical enterprises

This paper aimed to reveal the threshold effect of coal mining on ecosystem services in coal resource-based cities. Based on the stress threshold model of ecosystem services affected by coal mining, the stress threshold in Huaibei City was estimated from three perspectives of land destruction, groundwater resource destruction and air pollution to explore the temporal variation of stress effect of ecosystem service from 1990 to 2016. Results showed that coal mining had significant threshold effect on ecosystem service in Huaibei City, and the stress thresholds of land destruction, groundwater resource destruction and air pollution were 1803.19 hectares, 332.5323 million tons and 888.81 billion standard cubic meters, respectively. Meanwhile, the stress effect showed stage characteristics, during 1990~2009, ecosystem service was in good condition and none of the above three thresholds were exceeded; after 2010, groundwater resource of the region was affected by coal mining which exceeded the corresponding threshold and caused the degradation of ecosystem services. Fortunately, the worsening trend had slowed down since 2015. Therefore, this region must accelerate the construction of green mining areas, and strengthen the ecological management, and strive to prevent the stress effect of coal mining from exceeding the corresponding threshold to ensure the coordinated and sustainable development of economic growth and ecological environment.