In order to investigate the air pollution condition in Beijing-Tianjin-Hebei area during the Spring Festival in 2018, the pollution process was comprehensively analyzed by using near-surface pollutant concentration data and lidar observation data combined with WRF meteorological elements, particulate matter transport flux and HYSPLIT air mass trajectory. The results showed that there were three pollution processes during the Spring Festival. The concentration of PM_2.5 in each station did not exceed 200μg/m³ during the first pollution process before the Spring Festival. On New Year's Eve, the peak concentration of PM_2.5 at Langfang Station reached 504μg/m³, 26 times that of clean weather. From the second to the fifth day of the Lunar New Year, the PM_2.5 at each station was always higher than 120μg/m³, and the pollution was mainly concentrated below the height of 500 meters. There was high-altitude transportation in Beijing area, and the maximum transportation flux at 800 meters reaches 939μg/(m²·s). This heavy pollution process was a typical regional accumulation and transportation process. This study revealed that the Beijing-Tianjin-Hebei region is under strict control, and the peak concentration of PM_2.5 when fireworks are set off can reach 3.2 times of that when no fireworks are set off. In order to prevent the occurrence of heavy pollution during the Spring Festival, preventive measures need to be taken for setting off fireworks and firecrackers in stable weather.

The activity data for ten types of anthropogenic ammonia emission sources were collected in Hubei Province. The ammonia emission amounts of Hubei province during 1996~2016 were calculated by multiplying corresponding emission factors and activity data, and then were spatially relocated into 1km×1km grid cell with a GIS software. The diversities in ammonia emission structures and per unit emission for four types of geographic regions (the western mountainous cities, the central plain cities, the eastern megacity and other eastern small and medium-sized cities) were analyzed. The total ammonia emission in Hubei province increased from 375.0kt in 1996 to 475.4kt in 2016, with a yearly increasing rate of 1.2%. The ammonia increasing rate for the western mountainous cities was the highest of 3.5%, higher than the average increasing rate of the whole province. Agriculture sources were the major contributors for ammonia emission in Hubei Province, with the livestock and application of nitrogen fertilizers contributing 71.6% and 15.8% of total ammonia emission, respectively. Except for livestock and application of nitrogen fertilizers, the eastern megacity and the central plain cities held higher emission contributions of waste disposal (76.1%) and biomass burning (41.5%) among the four different geographic units, respectively. It was worth noting that the ammonia emissions from industrial production, human excrement, vehicle exhaust and fossil fuel combustion in the eastern megacity were all higher than those for other three geographic units, which should be paid more attention.

Based on the online monitoring data of atmospheric O₃ at University Town that located in the western Shenzhen in the past 5years, combined with the comprehensive observation of atmospheric pollutants, the evolution trend of atmospheric O₃ was obtained. In addition, the variations of meteorological conditions and the precursor's composition of O₃ during the exceeding standard periods were deeply explored in order to grasp the causes. The resultsshow that the increase rate of the maximum 8-hour average mixing ratio of atmospheric O₃ was 1.1×10^-9/a, and the exceed-standard rate was over 6%. High temperature and low humidity meteorological conditions were more likely to promote atmospheric O₃ formation. The increase of VOCs in the O₃ exceeding standard periods (70%~95%) was significantly higher than that of NO_x (28%), and the O₃ high concentration was distributed in the high VOCs and low NO_x region, indicating that the O₃ formation was mainly controlled by VOCs in University Town of Shenzhen. The toluene to benzene ratio (T/B) over 10at night during the O₃ exceeding standard periods suggesting that there may be a large amount of industrial emissions, while the consumption of OVOCs doubled at noon, indicating that OVOCs emitted by industrial activities may contribute significantly to daytime O₃ production.

The optical depth of black carbon (AOD_BC) was calculated by Mie scatteringtheory and vertical observation data of black carbon aerosol (BC) in Nanjing in June 2018 and October 2017, which was taken as the input parameters of Tropospheric Ultraviolet and Visible radiation model (TUV) to studyeffect of BC on the diurnal and vertical variations of photolysis frequencies (J[O¹D] and J[NO₂]). At 12:00 noon, the diurnal variation of photolysis frequencies had one peaking on the ground, but the attenuation of photolysis frequencies by black carbon(BC) were minimal.Then the maximum attenuation of J[O¹D] and J[NO₂] were-13.7% and -19.0% at 6:00 and 18:00. The relationshipbetween AOD_BC and photolysis frequencies was nonlinear, and the attenuation ability of BC to photolysis frequencies decreasedwith the increase of AOD_BC. When the value of solar zenith angle was 0°, photolysis frequencies were most sensitive to AOD_BC. In the boundary layer (0~1km), photolysis frequencies had a positive linear relationship with height, which was closely related to vertical variation of ultraviolet radiation, and the correlation coefficient (R)between it and photolysis frequencies was as high as 0.99. The attenuation degree of BC on photolysis frequencies increased with the decrease of height, but the vertical variation of it was very small and the maximum value of anomaly was only 0.1%.

Variations in aerosol optical andradiative properties, and aerosol potential sources are examined in a case of long-distance transport of biomass burning materialsfrom Southeast Asia to Kunming site in southwest China (April 5~8, 2013),based on the observational data of CE-318sun photometer in 2013, Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing products and HYSPLIT back trajectory analysis. The results showed that biomass burning activities were rare in southwest China during the pollution event, while there were a large number of biomass burning activities in Indo-China Peninsula in Southeast Asia. From April 5^th to April 7^th, the increasesin aerosol optical depth (AOD), extinction angstrom exponent (EAE), and absorption angstrom exponent (AAE) were observed. According to the classification methods withEAE and AAE, it was found that the Kunming sitewas mainly affectedby urban industrial aerosolduring April 5^th~6^th; on the contrary, biomass burning aerosol was the dominated type on April 7^th and 8^th. The peak radius of fine-mode (0.11μm) aerosol onApril 7^th and 8^th was smallerthan that on April 5^th and 6^th (0.15μm), and the peak concentrationof fine-mode aerosolvolume concentration (about 0.16μm³/μm²) on April 7^th was twice as much as that on April 5^th. The daily variation of aerosol direct radiation forcing (ARF) indicated that the most significant day for biomass burning aerosol pollution was April 7^th. On April 7^th, the cooling effect of aerosol on the surface temperature reached the maximum, and the heating effect on the atmosphere was the strongest. The changes of aerosol direct radiation forcing efficiency (ARFE) indicated that the cooling effect of biomass burning aerosol on the top of atmosphere was weakened. MODIS remote sensing data and HYSPLIT back trajectories showed that the biomass burning aerosols at Kunming site were mainly transported from Southeast Asia (mainly north India, northern India-Myanmar and Bhutan).

The Pt-Sn/Al₂O₃ honeycomb catalysts were prepared by incipient wetness sequence impregnation procedure (the content of Pt is only 0.06wt%), which were characterized by XRD, TEM and so on. The performances of catalysts were evaluated by selecting four representative C₆ hydrocarbons (benzene, cyclohexanone, cyclohexane and n-hexane). The optimal Pt/Sn ratio was 3/1 (w/w) in evaluating the catalytic activities, where the T₉₀ of four C₆ hydrocarbons decreased by about 20℃ compared with the Pt catalyst. Sn improved dispersion of Pt by dividing Pt into smaller clusters. The conversion of cyclohexane over Pt/Sn=3/1catalyst displayed no significant change after 720h of continuous run, in that Sn inhibited size growth effectively and Pt₃Sn alloy structure weakened the adsorption of C₆ hydrocarbons to reduce surface coke deposition.

In order to reveal the characteristics of odorous compounds released during the collection and transportation of municipal solid waste, typical compression and uncompressed vehicles for waste collection were monitored for 12months. 75kinds of odorous compounds were detected and classified into 6categories, among which the oxygenated compounds dominated by ethanol accounted for the highest proportion in concentration with the average concentration of higher than 360μg/m³. The corresponding odor pollution was more significant in autumn than that in winter. According to the statistical analysis of all the monitored data, there was no significant difference in type and concentration of odorous compounds between the compressed and uncompressed vehicles for waste collection. Five typical odorous compounds, including ethanol, naphthalene, dichloromethane, dimethyl disulfide and acrolein, were identified by using dilution multiple method. Due to the low olfactory threshold, the sulfur compounds can easily be detected by human even in very low concentrations, and should be paid more attention to during odor pollution control. This study provides important scientific information for the secondary pollution control of solid waste collection, transportation and management.

A rapid and real time detection system combing the laser spectroscopy with IWO-PSO-SVR is proposed for methane concentration. The detection system was designed based on near-infrared differential absorption and the best absorption wavelength at 1650nm and TDLAS and WMS. The power grows linearly from 5.0 to 10.6mW, the wavelength changed linearly from 1650~1651nm during the tuning process, the tuning rate increased from 0.0045 to 0.0115nm/mA. Gas samples were collected from a farm in Zibo, Shandong province in March 2019, 15samples date were randomly selected as the training set, the peak rare and methane concentration were used as the input and output values of the regression model, And the quantitative analysis model of algorithms of IWO-PSO-SVR、SVR、PSO-SVR and PSO-BP were established to predict the content of methane of test set. The experimental results showed that the IWO-PSO-SVR quantitative analysis model was effective:the Relative standard deviation of predicted and true values of four methane contents were 0.115%、0.109%、0.131% and 0.120%,less than 0.0014 respectively. The Determination coefficient were 0.9987、0.9966、0.9899 and 0.9975, high than 0.98 respectively. The elapsed time were 1.35, 1.54, 1.35 and 1.33s. After 1000 times of training, the detection accuracy of the model is 10^-5, compared with the same category detection system, it has high engineering application value.

During November 2018 and March 2019, a high-precision greenhouse gas analyzer and related auxiliary equipment were carried out by Yun-12aircraft to measure the CO₂ and CO concentration over Tangshan City from 200m to 4600m a.s.l to study the spatial and temporal distribution of CO₂ and CO concentrations over the city. During this observation period, six vertical profiles of CO₂ and CO concentration were obtained. The results showed that the CO₂ concentration varied from 406×10^-6 to 453×10^-6, while the CO concentration varied from 27×10^-9 to 1135×10^-9. For night observations when there were stable mixed layer, both CO₂ and CO concentrations reached their maximums at the top of the mixed layer. However, during daytime when there were no obvious mixed layer, both CO₂ and CO concentrations decreased with height. Significant correlations between CO₂ and CO concentrations were found when the averaged wind speeds were less than that of moderate breeze, and the CO₂/CO ratios ranged from 32.2 to 43.9. In the case study on February 2019, both CO₂ and CO concentrations elevated when the air mass passed over Tangshan, which indicated the city might be a carbon source in this situation, CO₂ flux can be further quantified by mass balance approach or inverse modelling.

The emissions of air pollutants from six typical airports in North China in 2017 were estimated using an improved method, which considered the mixing layer height calculated based on aircraft meteorological data relay (AMDAR) and improved the actual operation times of the aircraft under different modes. The total emissions of NO_x, CO, VOC, SO₂ and PM_2.5 of the six airports were 21504.2, 7074.8, 1424.0, 1283.6 and 323.2t, respectively. The emissions of NO_x, CO, VOC and SO₂ from aircraft were much larger than the other emission sources in the airport, while the emission contributions of PM_2.5 were similar. The HC and CO were mainly emitted during the taxi process, accounting for 90.6% and 90.2%, respectively. The NO_x、SO₂ and PM_2.5 were mainly emitted during the climb process, accounting for 58.9%,38.7% and 43.5%, respectively. The emissions of six airports in January were relatively lower than that in other months, and the largest emissions were occurred in August. Based on the detailed emissions inventory of the airports developed in this study, a WRF-CMAQ modeling system was applied to investigate the impact of the Tianjin Binhai International Airport emissions on the PM_2.5 concentration in the surrounding regions. The results indicated that the hourly maximum concentration contribution was 3.24μg/m³ in the airport area, The annual average and hourly maximum concentration contributions to the grids which were 5km away from the airport were 0.08 and 2.84μg/m³, respectively.

In order to study the dynamic behavior of non-spherical particles captured by magnetic fibers in the magnetic field, and based on the two kinds of dust, converter ash and refined ash, discharged from the converter and the refining furnace in the steel-making process in the iron and steel industry. The shape factor is calculated by formula, φ=0.21, 0.78, 0.81 and 1.00, respectively expressing the circular shape (thickness H=diameter of the bottom circle d/40), ellipsoid shape (radius of the equator of the x-axis:equator of the y-axis:z-axis polar radius=a:b:c=1:1:4), square shape and spherical particles. Under the same working conditions, the simulation results show that when the shape factor is close, the capture efficiency and moving track has nothing to do with the specific shape characteristics shown by dust particles. During the traditional single fiber capture process, while the inlet velocity v=0.1m/s and d_p>2.0μm, the larger the difference of shape factor is, the larger the difference of capture efficiency will be. The influence of shape factor on particles captured is positively correlated with the increase or decrease of single fiber capture efficiency. In the magnetic field produced by magnetic fiber, while v=0.1m/s and d_p>0.5μm, the larger the difference of shape factor is, the larger the difference of capture efficiency will be. When φ ≥ 0.4, the capture efficiency tends to be stable with the increase of shape factor, and the influence of shape factor on particles captured is not related to the increase or decrease of single fiber capture efficiency. In the high gradient magnetic field, when v=0.1m/s and d_p=1.0μm, a larger difference of shape factor leads to more obvious of a rule in which the difference between capture efficiency is larger. When v=0.1m/s and 0.5μm ≤ d_p ≤ 2.5μm, the influence of shape factor on particles captured is positively related to the increase or decrease of single fiber capture efficiency.

To obtainthe physical and chemical characteristics of particulate matter emitted from the tire wears of on-road vehicles, 17 kinds of selected tire tread were worn away by use of the tire profile simulation abrasion instrument. Tire wear particle samples were obtained, and 18 kinds of elements and 20 kinds of polycyclic aromatic hydrocarbons (PAHs) were extracted and detected. The results showed that the content of elements and PAHs varied significantly with different brand and speed level. The average content of 18 kinds of elements was (99.04±68.43) mg/g, accounting for 9.90% of the samples according to weight percentage, the average content of Si(88.97±67.85) mg/g, Zn(6.77±1.64) mg/g and Na(1.05±0.75) mg/g exceeded 1mg/g, the average content of Cd was (0.43±0.31)μg/g. The total content of 20kinds of PAHs changed from 12.13 to 433.64μg/g, the average content was (94.13±110.18) μg/g. The most abundant component was PY (30.98±31.27) μg/g, followed by CHR, BaP, FA, PHE and BghiP. Among them, AC contributes the lowest share with (0.58±0.2) μg/g on average. In term of the ring number, 4-ring PAHs were the major contents (accounting for 45.03%~67.93%), followed by 3-ring (15.45% on average) and 5-ring (12.62% on average) PAHs. In general, the contents of elements and PAHs in tires of foreign brands were slightly higher than those of domestic brands, while the numbers of PAHs rings were slightly lower than those of domestic brands.

In this study, a high-resolution steelmaking plants emission inventory for China (HSEC, 2018) was established to quantitatively simulate the environmental impact of various atmospheric pollutants emitted by Chinese iron and steel plants in 2018 and in the future years. The results showed that in 2018, the total emissions of SO₂, NO_x, PM₁₀, PM_2.5, PCDD/Fs, VOCs, CO, BC, OC, EC and fluoride were 290.2kt, 665.7kt, 287.3kt, 116.9kt, 2.24kg, 892.1kt, 40,574.9kt, 4.5kt, 6.1kt, 0.6kt and 8.8kt, respectively. Coking, sintering, pelletizing and blast furnace are the primary emission sources in Chinese iron and steel industry. Furthermore, Chinese iron and steel industry contributed 2.85%, 3.37% and 1.54%, respectively, to the average annual concentrations of SO₂, NO_x and PM_2.5 in each province. In the future situation, the emissions of SO₂, NO_x and PM₁₀ from China's iron and steel plants will be 49.4kt, 75.8kt and 41.1kt respectively, decreasing by 82.98%, 88.61% and 85.69%, respectively. The corresponding contributions of Chinese iron and steel industry to the annual average concentration of SO₂, NO_x and PM_2.5 in each province will be 0.31%, 0.22% and 0.02% in this case, respectively.

The kinetic characteristics of aerobic ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under different influent NH₄⁺-N loading and free ammonia (FA) concentration were studied by biofilm-activated sludge composite process (IFAS). The contributions of different microbial aggregates (suspended sludge and attached biofilm) to the removal of NH₄⁺-N were investigated, and the biological adsorption and biodegradation were analyzed quantitatively. The amount and spatial distribution of total bacteria, AOB, and NOB were observed by fluorescence in situ hybridization (FISH). The experimental results showed that with the increased of influent NH₄⁺-N concentration, the effluent NO₃^--N concentration decreased and the NO₂^--N accumulated a lot. When the influent NH₄⁺-N concentration was 480mg/L, the NH₄⁺-N removal rate and the nitrite accumulation rate (NAR) were stable above 95% and 80%, respectively, while the FA increased from (2.77±0.07) mg/L to (16.35±0.3) mg/L, and the NAR increased from 9.42% to 83.31%, which achieved the inhibition of NOB. In the process of NH₄⁺-N removal, biossorption and microbial degradation accounted for 3.4% and 88.1% of NH₄⁺-N removal, respectively. The ratio of AOB in suspended sludge and biofilm increased from 27.4% and 10.3% to 41.3% and 18.1%, respectively, indicating that suspended sludge was more beneficial to enrichment of AOB than biofilm.

Anovelfixed-bed biofilm process based on partial denitrification/anammox (PD/A) was developed for the simultaneous treatment of low C/N domestic wastewater and secondary effluent. The nitrogen removal performance of the process at different influent C/N (1.3, 1.5, 1.6, 1.8) and different pH (7.5, 8.0, 8.5, 9.0) was studied. Results showed that increasing influent C/N enhanced the complete denitrification of the system, whichincreased the average removal rate of NO₃^--N from 52.3% to 85.7%; The higher influent pH promoted theNO₂^--N accumulation in partial-denitrification process, and then enhanced the autotrophic nitrogen removal by the anammox, which increased the average removal rate of NH₄⁺-N from 82.2% to 89.7%. Under the conditions of C/N=1.6 and pH=9.0, 88.3% of TN removal rate was achieved, and the effluent TN was stable less than 2mg/L. Moreover, the potential of the fixed-bed biofilm process based on PD/Ain the upgrading of traditional AAO process was analyzed.

A sleeve-type mechanically stirred ammonium magnesium phosphate crystallization-inclined plate enhanced precipitation reactor was developed to treat wastewater containing high concentration of nitrogen and phosphorus, and recover ammonium magnesium phosphate crystals. The effects of stirring speed, hydraulic retention time and total number of particle collisions (GT value) on reactor performance were investigated. The computational fluid dynamics software (Fluent 18.1) was used to conduct numerical simulation of the flow pattern in the reactor, and the rationality of reactor structure design was analyzed. This would provide technical reference for the design and operation of the ammonium magnesium phosphate crystallization-precipitation reactor. The results indicated that the average recovery of ammonia nitrogen and phosphorus was above 76.00% and 97.00%, respectively, when the stirring speed was 250r/min, the hydraulic retention time was 0.375h, and the average GT value was from 14,000 to 20,000. Under such operating conditions, the average particle size of crystal reached 20.515μm, and the turbidity of effluent was below 2NTU. The results of scanning electron microscopy and X-ray diffraction showed that the precipitate in the reactor was pure magnesium ammonium phosphate. There was an obvious hydraulic grading in different areas of the reactor, with a turbulent flow pattern in the mixed reaction crystallization zone, a transition flow regime in the buffer zone and the collecting zone of magnesium ammonium phosphate, and a laminar flow pattern in the solid-liquid separation zone. The flow characteristics of the reactor showed that its structural design could meet the hydraulic requirements for crystal formation and growth as well as the solid-liquid separation under suitable operating conditions.

In this study, we developed a facile strategy to modify a forward osmosis thin-film composite (TFC) membrane via surface grafting of silica nanoparticles (SiNPs), which was functionalized with amine moieties (3-Aminopropyl trimethoxysilane, APTMS). The APTMS functionalized SiNPs were grafted on the negatively charged TFC membrane via electrostatic interactions during a dip-coating process, to enhance membrane hydrophilicity and impart fouling resistance. After modification process, dense nanoparticles were found grafted on membrane surface. Compared to the pristine membrane, contact angle of the modified membranes significantly reduced by 54%, while surface zeta potential and roughness presented negligible changes. For dynamic fouling tests using sodium alginate as a model foulant, flux behavior and fouling layer characterizations revealed that the modified membranes exhibited notably fouling resistance than the pristine membrane during later period, with flux decline remarkably reduced by 28% and deposited foulants decreased by 35%. The antifouling property of the membrane was mainly attributed to substantial hydrophilicity enhancement due to APTMS-SiNPs functionalization.

A sequencing batch reactor (SBR) was operated in this study to investigate the effect of pH on the kinetics of NOB activity.For revealing the details the activated sludge abundant with NOB was used as an object and several statistics analyses based on Monod model were also applied. The results showed that the Monod equation fitted the experimental data well, and the greatest NOB activity was achieved as Ks=6.167mg/L, r_max=1.13g/(g·d) under pH=7.0.The analyses of bell-shaped empirical model disclosed that r_max varied in a bell shape as pH value increased. The optimum pH was 6.9±0.1whilethe r_max maintained above a half of the greatest r_max(r_opt) was 3.26±0.4. The real-time PCR analysis results showed that the variation trend of nxrA gene and nxrB gene is consistent with the rule of kinetic parameters, and both nxrA and nxrB genes worked in the degradation process of the system.

In this paper, BiOCl was prepared by microwave-assisted hydrothermal synthesis method using bismuth nitrate pentahydrate, potassium chloride, ethylene glycol and P123 as raw materials. Microwave power, temperature and microwave holding time were changed to determine the conditions of the BiOCl preparation for the best photocatalytic degradation of metronidazole. The optimal synthetic condition of BiOCl was determined to be 600W, 120℃ and 30 min, under which the synthetic product showed the best degradation on metronidazole under simulated sunlight. The prepared materials were characterized by XRD and SEM to investigate crystal structure and surface characteristics of BiOCl. Besides, the effect of reaction conditions such as catalyst dosage, metronidazole initial concentration and pH on the degradation of metronidazole were also investigated. At the condition of catalyst dosage 2.5g/L, metronidazole concentration 5mg/L and pH 3, the degradation efficiency of metronidazole reached to 98.3%. The capture experiment indicated the main active species wereholes (h⁺) and superoxide radical (·O₂^-) in the degradation of metronidazole.

This study sampled and analyzed 6 municipal solid waste (MSW) landfill leachates and 3 raw and treated MSW incineration leachates in southwestern China. The concentrations of 17 target PFAS ranged from 1805 to 43310, 7228 to 16565, and 55 to 185ng/L, respectively. The major PFAS were short-chain and even-chain substances represented by perfluorobutanoic acid (PFBA) and perfluorobutane sulfonic acid (PFBS). Comparison of landfill and incineration leachates in the similar service area revealed that PFAS compositions in both leachates were similar. The PFAS concentrations in raw incineration leachates were higher than that of "old" landfill leachates (operation time:~15a) and similar to "young" landfill leachates (operation time:~2a). These results will provide the PFAS occurrence data important for prevention and control of environmental pollution due to PFAS production and use in southwest China.

To reduce the security risks of traditional ultraviolet (UV) disinfection technology alone, tea polyphenols (TP) was used in conjunction with UV disinfection. The effects of UV-TP combined disinfection and the changes of biofilm and bacterial community structure were investigated using a simulated water supply network composing different pipe materials and hydraulic retention times. The results showed that 75mg/L was a better dosage of tea polyphenols when combined with UV disinfection,which can maintain the disinfection effect for 48hours. The quality of treated water remained better in the testing process of the simulated system, but the pipe material had a greater impact on the disinfection effect of the pipe network. The frequency of bacteria exceeding 100CFU/mL in the ductile iron (DI) and unplasticized polyvinyl chloride (UPVC) pipe network within 30days were 80% and 0%, respectively. UV-TP combined disinfection in the UPVC pipe network has a relatively strong disinfection.Compared with UV disinfection alone, UV-TP combined disinfection resulted in a reduced rate of biofilm build up and is more effective in inactivation of Cyanobacteria and intestinal pathogens, which is beneficial to ensure the required quality of the water supply network.

The methylene blue aqueous solution has been treated by dielectric barrier discharge plasma technique as simulated wastewater. Nickel, iron, molybdenum and stainless steel were used as electrodes. The effects of different electrode materials on the degradation rate and energy efficiency were investigated under parallel magnetic field. It has been found that the difference in electrode materials could affect the degradation of methylene blue. For the nickel electrode, the degradation rate of methylene blue could reach 99% after 8min treatment, which could induce the best effect of degradation. The electrode material could also affect the promotion of parallel magnetic field on the degradation of methylene blue. The energy efficiency of iron and nickel electrodes could increase 20% compared to no magnetic field, while molybdenum and stainless steel only 5%~10%. By applying the mechanism of the dielectric barrier discharge (DBD) plasma and the secondary electron emission theories, it has been found that these differences were caused by the differences in secondary emission coefficient and magnetic permeability of the electrode material. The secondary emission coefficient of nickel is the largest among the four materials, so it has the best degradation effect. Iron and nickel had larger magnetic permeability, and the magnetic induction intensity in the discharge space was higher, which induced the more definite improvement of the parallel magnetic field on the degradation rate and energy efficiency of methylene blue.

Rutheniummycin was used as the degradation target, and the α-FeOOH photocatalyst was prepared by precipitation method, and further loaded on the ceramic membrane by covalent bonding method and characterization of α-FeOOH and photocatalytic ceramic membranes by SEM, XRD, EDS, UV-Vis and FTIR. The results showed that the catalyst α-FeOOH was acicular or spindle-shaped, with a length and width of 500~550nm and 25~50nm, respectively. The porosity of the ceramic membrane modified by α-FeOOH is changed from 14.83% to 8.11%. The degradation efficiency and kinetic behavior of fentanyl ceramic membrane coupling system were studied. The optimal degradation conditions of the photo-Fenton ceramic membrane coupling system were determined as the initial concentration of chlortetracycline 50mg/L, H₂O₂ concentration 10mmol/L, UV intensity 3796.6μW/cm². The degradation mechanism of chlortetracycline in the two systems was further analyzed by UV-Vis spectroscopy. Under the photocatalyst system, the concentration of H₂O₂ remained basically unchanged, while the concentration of H₂O₂ in the photo-Fenton ceramic membrane coupling system first rose and then decreased, and the latter had higher removal rates of TOC and NH₄⁺-N at the same time point, indicating that the photo-Fenton ceramic membrane coupling system has stronger oxidizing ability and more complete degradation of chlortetracycline.

Sludge activated carbon (SAC), TiO₂/SAC and Fe₃O₄/SAC were used as the sensitizers to enhance the decomposition of excess sludge associated with microwave. Based on the analysis of chemical oxygen demand (COD), DNA, nitrogen, phosphorus and organic matters from the filtrate, the optimal conditions were investigated. After loading TiO₂ and Fe₃O₄ on SAC, the dielectric loss and hysteresis loss of electromagnetic wave were enhanced. When the dosage of TiO₂/SAC was 0.25g/gSS, the filtrate COD concentration was 1900mg/L, which increased by factors of 4.52 and 1.86 to the excess sludge and sludge treated by microwave, however, the addition of Fe₃O₄ is more conducive to the decomposition of excess sludge, the filtrate COD content was up to 2540mg/L, which was 6.05 times and 2.45 times higher than that of excess sludge and sludge treated by microwave. In addition, the filtrate total phosphorus (TP), total nitrogen (TN), protein and polysaccharides concentrations increased by factors of 7.7, 16, 7.49 and 71.69, indicating that a large amount of intracellular and extracellular polymeric substances released to filtrate and further greatly increased the soluble content of organic matters. The pretreatment method of microwave + sensitizer is beneficial to resource utilization and recovery of nitrogen, phosphorus and organic matters in excess sludge.

In order to optimize the pretreatment conditions, this work investigated the contribution of different dosages of potassium ferrate (PF)/sodium sulfite (Na₂SO₃) on EPS disintegration and SCFAs production. The results showed that the coupling oxidation of Fe(VI)/S(IV) showed promising lysis performance, especially for the tightly-bound EPS. When the molar ratio of PF/Na₂SO₃ increased from 0/1(sole Na₂SO₃) to 2/3, SCFAs concentration increased from 1169.5mg COD/L to 4796.9mg COD/L(at 4d), which was 4.5 fold and 1.6 fold over that obtained in the sole Na₂SO₃ and PF tests. Meanwhile, under this condition, the release of soluble carbohydrates and proteins reached their peaks of 260.1mg COD/L and 2212.2mg COD/L, respectively. Therefore, the optimal molar ratio of PF/Na₂SO₃ for SCFAs production was 2/3. Based on the results obtained in this study, the mechanism of Fe(VI)/S(IV)/oxidation for accelerating SCFAs production from WAS was elucidated, which provided a theoretical basis for the potential implementation of SO₄^·- based advanced oxidation methods on WAS fermentation.

In order to explore the effects of molding shape and landfill method on the leaching of heavy metals in the solidified fly ash of municipal solid waste incineration, the size of solidified body was set to 10×10×10cm, 10×10×2.5cm and DN=3cm (sphere) respectively, and at the same time set two landfill methods-orderly stacking and scattered stacking-for dynamic leaching test. The results showed that the leachate pH between spherical shape and cuboid shape, orderly stacking and scattered stacking were significantly different before the solidified body cracked; The cumulative leaching amounts of Pb, Zn and Cr per unit mass of solidified body increased with the increase of solid-liquid contact area, scattered degree of landfill and liquid-solid ratio. The leaching of solidified and stabilized fly ash conformed to the shrinking core model and was mainly controlled by the diffusion process. The two kinds of rate constants of Pb, Zn and Cr were positively related to solid-liquid contact area, scattered degree of landfill and liquid-solid ratio. Therefore, it is necessary to reduce the leaching of heavy metals from the raw ash of municipal solid waste incineration plants and improve the security of co-disposal of solidified and stabilized fly ash in the landfill sites. The surface area of solidified body should be minimized. And the solidified body should avoid being buried by using a scattered landfill method.

Seventy floodplain soil samples were collected by the CGB sampling team at 35locations in the karst area of Yunnan, Guizhou, Guangxi to study the distribution, sources, the pollution degree and ecological risk of 8heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) by factor analysis, geo-accumulation index (I_geo), enrichment factor (EF) and the Hakanson's potential ecological risk index (E_rⁱ and RI) methods. Results showed that the concentrations of all elements were almost higher than their soil background values of China. Cd and Hg were significantly enriched in the top soils, while As, Cr, Cu, Ni were similar in top and deep soils. The high values of heavy metals were concentrated in southeast of Yunnan, while the low values were concerted in northwest of Guangxi. The contents of As, Cd, Hg, Pb and Zn in top soil from farmland and vegetable land were significantly higher than those in deep soil, while the Cr, Cu and Ni were comparable to those in deep soil from all land-uses. The Factor analysis results indicated that Cd, Cr, Cu and Ni in the top soils were mainly affected by geological background, As, Pb and Zn were not only related to the natural conditions, but also affected by human activities, Hg were affected by anthropogenic contamination; all heavy metals were inherited the characteristics of regional parent rocks in deep soil, while As, Hg and Pb were also affected by human activities. The results of I_geos and EFs showed that Cd and Hg were seriously polluted in the top soils, As, Cr, Cu, Ni, Pb and Zn were mainly light polluted or non-polluted. The ecological risk calculated by ecological risk indexes (E_rⁱ) were ordered by Hg > Cd > As > Cu > Ni > Pb > Cr > Zn. The sum E_rⁱ of Cd and Hg accounted for 82.43% of the comprehensive indexes of potential ecological risks (RI), indicated that the top soil of floodplain occured high potential ecological risk of Cd and Hg. Moreover, the southeast of Yunnan had the highest RI of heavy metals, and had the severe ecological risk in the study area.

Soil organic matter is one of the most important factors that affects the environmental behavior of polycyclic aromatic hydrocarbons (PAHs), and there are differences in the bioavailability and environmental risks of PAHs among different soil organic matter fractions. The contents and compositions of 15priority PAHs and their distribution patterns in the light (LF) and heavy fractions (HF) of six field-contaminated soils were studied. The toxicity equivalent concentration of benzo[a]pyrene (TEQ_BaP) was adopted to assess the ecological risks of PAHs in the bulk soil, as well as in the LF and HF. The results showed that the contents of the fifteen PAHs in the six soils ranged from 8.31×10² to 2.97×10⁴ μg/kg, and the 4-ring PAHs accounted for the highest proportion, which ranged from 35.7% to 59.6%. In the six soils, the contents of total PAHs were in the ranges of 2.38×10⁴~1.17×10⁵μg/kg for the LF and of 3.7⁵×10²~2.12×10⁴μg/kg for the HF. Although the LF accounted for only 1.0%~9.8% of the total soil mass, it accounted for 5.9%~60.6% of total soil PAHs. TEQ_BaP of the total fifteen PAHs in the LF ranged from 2.99×10² to 1.68×10⁴μg/kg, which was 2.7~33.2 times of those in the bulk soil and 3.6~69.5times of those in the HF, respectively. For the remediation and risk assessment of PAHs in contaminated soils, PAHs in the LF must be emphasized. In contaminated soils where the proportions of PAHs bound with the LF are high, removing the LF from the bulk soil would be an alternative remediation method.

Aquatic life freshwater quality criteria of Sb for protecting aquatic lifewas absent to date in China. In this study, freshwater species and relative toxicity data of Sb were collected and screened. To derive aquatic life ambient freshwater quality criteria of Sb, assessment factor method, toxicity percentile rank method, and species sensitivity distribution(SSD) method were used in this study. Acute quality criteria and chronic quality criteria, which wererecommended as the freshwater quality criteria of Sb, were derived to be 466.62and 88.71μg/Lbased on SSD method. After comparison and analysis with existing relevant water quality standard in China and internationally, water quality standard of Sb in China was suggested to be revised as "water quality standard for the protection of freshwater aquatic organisms" and "water quality standard for the protection of human health" respectively to avoid "over-protection" of water quality standards for aquatic organisms.

The stable isotope compositon of water (δD and δ¹⁸O) were collected in November 2018 and March 2019 along the Lijiang River to estimate their indication of the evaporation. The results showed that:the δD and δ¹⁸O values had different composition characteristics among different sampling sietes in the the Lijiang River, the δD and δ¹⁸O values of groundwater was smaller than those of surface water, the δD and δ¹⁸O values in the wet season were easier to enrich than in the dry season; The variation trend of δ¹⁸O value was more obvious than d-excess under the increasing of water temperature. The elevation gradually decreased from the upstream to the downstream, and the slope and intercept of Lijaing River water line also gradually decreased; Underground river water line and Lijiang River water line were closely to local meteoric water line(LMWL), indicating that there was a close hydraulic connection between underground river, Lijiang River and precipitation in the study area. Due to the influence of temperature and humidity, the evaporation proportion of Lijiang River in wet season and dry season were 0.7%~9.1%,2.6%~9.7%, respectively; The evaporation proportion from upstream to downstream gradually increased in the study area, regardless of in wet season or dry season. The evaluated evaporation value based on isotope mass balance model in the study area was 959.40mm, which was less 43.11mm than the multi-year monitoring data, with the relative error of 4.70%; Using stable isotopes (δD and δ¹⁸O) is an essential method to study the hydrological cycle in a river basin, thus stable isotope still has a wide application space in hydrological cycle in Lijiang River Basin.

Eight sediment samples were collected in Daliao River. The composition and distribution characteristics of microplastics in this study were studied by density flotation method combined with stereo microscope and μ-FTIR. The results showed that the average abundance of microplastics in sediments was (66.67±79.93) items/kg. DL5, located in AnShan Hai Cheng city, had the highest abundance of (193.33±172.43) items/kg; DL6, located in Liuhao, town of Liaoyang country had the lowest abundance of (20±34.64) items/kg. The main colors of microplastics were white, black and yellow (83.75%). The main shapes of microplastics were fiber, film and debris (91.25%). The main particle size of microplastics were 1000~2000μm (33.75%). It can be concluded that the main components of film microplastics were polyamide (PA), polypropylene (PP) and polyethylene (PE), the main component of the debris microplastics were polyethylene (PE) and polypropylene (PP),the main components of foams and particles was polystyrene (PS), and the main components of fibers were Rayon(RY) and Polyethylene terephthalate (PET). On the whole, the abundance of microplastics in sediments of Daliao River is at a moderately low level. The results can provide basic and scientific data for the study on the pollution distribution of microplastics in sediments of freshwater rivers in China.

To study the photodegradation kinetics of bisphenol A (BPA) and the photolysis effect of the main water components in estuarine water, the real water sample was collected in the estuarine waters connecting the Maowei Sea and the Dalan River in Qinzhou city, China. The photodegradation kinetics of BPA in estuarine water sample and the effects of Cl^-, Br^-, dissolved organic matter (DOM), NO₃^-, HCO₃^-, and ionic strength on the photolysis of BPA were studied by simulated sunlight experiment. The results showed that the photolysis rate constant (k) value of BPA in estuarine water was higher than that in pure water, and the k value of BPA in the upstream water sample was 2.5 times as compared to the downstream water sample. Steady-state photolysis experiments showed that DOM and its interaction with halogen ions significantly affect the photolysis of BPA. Although NO₃^- also affected the photodegradation kinetics of BPA, the effect of NO₃^- was not obvious when it was concomitant with DOM. Radical quenching and competitive reaction kinetics experiments found that the triplet-excited state DOM (³DOM*) and halogen radicals (HRS) are the main reactive species that dominate the photodegradation of BPA in estuarine water samples. Moreover, the reactivity of ³DOM* with BPA (second-order reaction rate constant, k_3DOM*,BPA=4.42×10⁸L/(mol·s) was higher than that of HRS with BPA (k_BPA,Cl·=2.11×10⁸L/(mol·s),k_BPA,Cl2·-=8.5×10⁶L/(mol·s). The relatively high concentrations of halide ions (292mmol/L) in downstream water samples can easily quench ³DOM* to generate HRS with relatively low reactivity towards BPA,which can explain the phenomenon that the photolysis rate constant of BPA in the downstream water sample was lower than that of the upstream water sample.

Surface water and undergroundwater were collected from the eastern part of Qilian Mountains (Wushaoling, Gulang, Tianzhu) from May to September, 2016~2017. Water chemical analysis, statistical analysis, Piper three-line diagram, Gibbs diagram and ion ratio were used to explore the main ion composition, source and temporal & spatial variation of surface water and undergroundwater in the area. The result shows that the main cations of theeastern part of the surface water and undergroundwater in Qilian Mountainsare Ca²⁺ and Na⁺. The average concentration of Ca²⁺ is 76.897mg/L, accounting for 73.89%.AndNa⁺ is 16.592mg/L, accounting for 15.94%. The dominant anions are HCO₃^- and SO₄^2-. The concentration of HCO₃^- is 190.117mg/L, accounting for 68.71%. SO₄^2- is 67.565mg/L, accounting for 24.42%. The water hydrochemistry type is HCO₃^--Ca²⁺ concerning Wushaoling River water, Wushaoling undergroundwater, Tianzhu riverand Tianzhuunderground water.In the light of Gulangriver water and its underground water, the type is HCO₃^--Ca²⁺-Mg²⁺. Ions ofdifferent waters are from rock weathering, meanwhile affected by carbonate and silicate weathering and dissolution combined, and human activity is alsocontributed. The time-varying characteristics of the main ions concentration in different water bodies are different.In general, the ions concentration of most water bodies does not change significantly with time, and the overall trend is relatively flat.

Based on the field investigation, dynamic monitoring and data analysis, the present study took the Hunhe River Basin as the research area according to the actual conditions of Hunhe River Basin included hydrological and hydrogeological conditions, and established the coupled model of surface water and groundwater current and water quality respectively. The simulation objects included surface water, aeration zone water and saturated zone water. The present study associated surface water with ground water and solved simultaneously by using HydroGeoSphere (HGS) technology system, and respectively corrected and tested the coupled model of surface water and groundwater current and water quality based on synchronization dynamic monitoring data of surface water and ground water. Further, with the setting circumstances, the present study predicted the future water pollution status of surface and ground water in Hunhe River Basin using the coupled model established before. These results showed that the coupled model of surface water and groundwater current and water quality based on HGS technology system can depict the movement rules of surface water and groundwater respectively, as well as the hydraulic relation and law of mutual transformation between them. If the surface water is polluted (e.g., fertilizing farmland), not only impact itself but also affect the groundwater, and vice versa.

This study aimed to reveal the characteristics of the bacterial community structure in the groundwater fluctuating region and its interaction with the groundwater environment in the First Water Resource in Harbin, Northeast China. Groundwater samples were collected for water chemical analysis and aquifer media samples at different depths in the fluctuating region (0~5m unsaturated zone and 6~50m saturated zone) for bacterial community analysis by 16Sr RNA. Redundancy analysis was used to indicate the correlation between groundwater quality parameters and the bacterial community. The main groundwater pollutants in the study area were Fe, Mn, NH₄⁺ and organic matter. The excess of Fe and Mn was mainly related to the specific geological background of northeast China. The NH₄⁺ and organic matter were mainly derived from human activities. There was a significant difference in the bacterial community structure between the unsaturated and saturated zones, and the abundance and diversity of the bacterial community in unsaturated zone were significantly higher than those of the saturated zone. Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes and Acidobacteria were the dominant bacteria in the study area, for which the accumulative relative abundance in the unsaturated and saturated zones was 82.89% and 98.64%, respectively. Bacteroidetes, Proteobacteria, Actinobacteria and Verrucomicrobia were closely related to groundwater quality evolution at the phylum level in the unsaturated zone, with contribution rates of 15%, 14.8%, 8.9% and 5.2%, respectively. Bacteroidetes, Acidobacteria, Actinobacteria and Firmicutes played a major role in the groundwater quality evolution process in the saturated zone, with contributions of 38.4%, 19.0%, 10.8% and 9.1%, respectively. Both Pseudomonas in the unsaturated zone and Flavobacterium in the saturated zone had a critical influence on the biotransformation of Fe, Mn and NH₄⁺ at the genus level. This study provides a scientific basis for revealing the impact of biogeochemical effects on groundwater environment in groundwater fluctuating regions, and is of great relevance for groundwater pollution restoration.

A coal gangue pile in Fushun City was selected as the study area, and the groundwater numerical simulation model for this area was established based on physical condition. After that, we applied the model in predicting possible spatial and temporal variation of groundwater pollutant in research area. Based on forward modelling, a hypothetical example was designed to explore the application of simulation-optimization method and simultaneously carried out inverse identification of groundwater pollution sources and model parameters. The Kriging method and BP Neural Network method were proposed to establish a surrogate model of the groundwater numerical model so as to reduce the computational load caused by the repeated invocation of the simulation model by the optimization model, and the surrogate model was then integrated to simulation-optimization model where simulated annealing method was used. The study reached the following conclusions:As the surrogate model of the simulation model established by Kriging method, the mean relative error of the output concentration is 0.3%, by contrast with 1.5% with BP Neural Network method. The identification error of the release intensity of pollution source with two methods are both below 0.5%, and the identification error of hydraulic conductivity both partitions is no larger than 5%. Above all, the accuracy of surrogate model established by Kriging method is higher than BP neural network method. It is proved that the inverse identification by using the simulation-optimization method based on two surrogate models is effective and accurate.

In this study, the typical agricultural area of Huaxi river basin in Guiyang city was selected as the research object. The distribution characteristics, the source and forming process of nitrate in surface and ground water were revealed by the isotopes (δ¹⁵N-NO₃^-, δ¹⁸O-NO₃^- and δ¹⁸O-H₂O) and hydrochemical analysis. Meanwhile, according to the SIAR (stable isotope analysis in R) model, the contribution rates of different nitrate sources in surface and groundwater were also identified quantitatively. The results showed that:(1) The HCO₃-Ca type was main hydrochemical types controlled by the weathering of carbonatite, and the spatial distribution characteristics of nitrate in the water were significantly affected by land use type; (2) The nitrification played a leading role in the formation of nitrate in the water, and Nitrate in the water mainly came from fertilizers, ammonia salt in rainfall, soil organic nitrogen, feces and sewage. Compared with surface water, nitrate in groundwater was more affected by feces and sewage; (3) Based on the SIAR model, the contribution rates of precipitation, fertilizer, soil organic nitrogen, and manure/sewage were 3.97%, 26.87%, 36.80% and 32.37% to nitrate in surface water and 2.83%, 13.96%, 21.03% and 62.18% to nitrate in groundwater, respectively.

Based on the 1258 shallow groundwater samples of Dongting Lake region, the spatial distribution of Eh was analyzed by geostatistical method, and the redox zoning of groundwater system in the lake region was carried out by using the concentration spatial data of redox sensitive indexes. The results show that, controlled by geological structure, stratigraphic lithology, swamp wetland and paddy field, spatial distribution of Eh in Dongting Lake region shows a decreasing trend from hilly areas to the hinterland of the lake, which reflects a fact that, groundwater environment gradually changes from relative oxidation to relative reduction. Groundwater system in Dongting Lake area can be divided into three redox zones, which arestable and reductive zone, manganese (IV) reductive zone and iron (III) reductive zone. In general, the three zones reflect the spatial distribution of Eh well, although the zones and Eh are not in synchronizationin some regions for Mn enrichment in aquifer media.

In this study, the iron-manganese (Fe-Mn) co-oxide filter media were adopted from a pilot-scale water treatment plant. This plant has been running for 5years continuously. Both the static and continuous flow column experiments were conducted to explore the performance and mechanism of tetracycline removal by the Fe-Mn co-oxide filter media. The results indicated that the removal process followed the quasi-secondary reaction kinetics model. The better removal efficiency could be obtained with increasing the material quantity and initial concentration. When the concentration of coexisting cations reached 0.01mol/L, the inhibition of tetracycline removal could be observed. Nevertheless, Ca²⁺、K⁺ exhibited little effect on the tetracycline removal. Through the continuous flow column experiment and the toxicity evaluation based on luminescent bacteria, it indicated that the Fe-Mn co-oxide filter media had higher tetracycline removal efficiency than that of the original quartz sand filter media, and the acute toxicity was reduced after treatment by the Fe-Mn co-oxide filter media. In addition, the experimental results of mechanism exploration confirmed that the removal of tetracycline by the Fe-Mn co-oxide filter media was a combined process of adsorption and oxidation.

To explore the influence of artificial forced mixing and oxygenating on the bacterial community structure, we analyzed the bacterial community structure in Xi'an Jinpen reservoir from August 2018 to April 2019. The results showed that Cyanobacteria、Actinobacteria and Proteobacteria were the dominating bacteriaes in the whole water. The abundance of Cyanobacteria decreased from 11.7%~19.2% to 6.3%~8.9% due to the artificial forced mixing and oxygenating. The abundance of Cyanobacteria decreased from 18.3%、11.7%、19.2% to 8.9%、6.3%、7.9% in surface、middle and bottom water. The difference of the bacteria structure and the dispersion between samples were reduced because of the artificial forced mixing effect. Theabundances of Actinobacteria and Proteobacteria gradually change from "middle > bottom > surface" and "surface > bottom > middle" to be consistent in the surface、middle and bottom water. Thecontent of dissolved oxygen and the abundance of aerobic bacteria were increased due to the artificial forced oxygenation effect at the bottom. The abundances of Polynucleobacter、Methylocystis、Methylobacter increased from 0.06%、0.18%、0.02% to 1.06%、2.20%、1.96%. According to the redundancy analysis, the mainfactors that affected bacterial community composition were the thermal stratification stability,water temperature, DO, TP and TN.

Based on the analysis of X-ray fluorescence (XRF) elements and magnetic susceptibility (MS) of Fuxian Lacustrine sediments, the characteristics of soil erosion and human activity had been discussed since 1840AD combined with cluster analysis, principal component analysis and other environmental proxies. The results showed that the characteristics of XRF core-scanning elements by the cluster analysis could be divided into 34~24cm(1715~1813AD), 24~9cm(1813~1947AD) and 9~0cm(1947~2018AD). The principal component analysis of element ratios and MS showed that the variance contribution rates of principal component 1 and 2 were 37.72% and 25.73%, respectively. The factor loading of Rb/Sr, Ti/Sr and Ti/Rb, which indicated the erosion strength of the lake catchment, were exceed 0.6. It indicated that the element ratios of exogenous detrital sediment had the better indicative implications for erosion and human activity intensity of Fuxian lake catchment. Therefore, the erosion and human activity intensity of lake catchment had been reconstructed by using the environmental proxies of lacustrine sediments. Human severe activities enhanced the erosion of Fuxian lake catchment since 1840. From 1990s, erosion intensity exhibited overall weak because of the ecological restoration of lake catchment.

In this paper, we applied a continuous fractionation method to analyze the spatial distribution, occurrence characteristics and release of fluorine in the interstitial water, surface sediments and core sediments of DaiHai Lake, with aiming to reveal the migration and transformation of fluorine in the water-sediment of DaiHai. Investigation results showed that the average of the fluoride ion concentration in the interstitial water was (4.82±0.06)mg/L, which largely exceeded the threshold in National surface water standard criterion Ⅴ(1.5mg/L). Moreover, the relative concentration of fluoride ion between the interstitial water and the overlying water(4.77mg/L) remained stable. The average of the total fluoride in the surface sediments was (934.13±36.79) mg/kg, including (34.39±1.69)mg/kg water-solution fluoride, (7.11±0.93)mg/kg exchangeable fluoride, (3.07±0.50)mg/kg Fe/Mn bound, (11.97±0.79)mg/kg Organic bound and (934.13±36.79)mg/kg residual fluoride. In the core sediments, the fluoride ion concentrations of water-solution, exchangeable, Organic bound reduced with sediment depth increasing, and kept stable under 40cm; however, the fluorine of Fe/Mn bound was low in the surface and became stable under 25cm. Depending on the multiple regression analysis, both the amount of the water-solution fluorine and exchangeable fluorine of the sediment had much positively correlated with the fluorine in the interstitial water, and the fluorine had a strong migration ability. The stability risk assessment indicated that the range of SAC in the surface sediments was between 55.53%~69.52%, with the average being 60.63%, but in a largely unstable state. In addition, the SAC would decrease from the surface down 20cm, which indirectly reflected that the concentration of extractable fluoride had been obvious in recent years, with strong releases risk.

In this paper, determinations of phosphorus forms, methane and sulfate and so on were implemented in the typical pockmark area of north Yellow Sea to explore the controlling mechanism of phosphorus transformation and burial under this unique environment and its effect of phosphorus release from sediment-water system on regional phosphorus cycle. The results showed that Det-P(>50%) was the dominant P form in the sediments, followed by Org-P, Fe-P and Auth-P. Exch-P was the minor phase of Tot-P. The diffusive fluxes of dissolved reactive phosphorus (DRP) at B9 and B11 stations were 2.84μmol/(cm²·a) and 1.03μmol/(cm²·a), and their contributions to surface water P loadings were 19.6% and 3.03%, respectively. Observed burial and transformation of phosphorus in and out the pockmark were different; the leakage of groundwater in the study area was the reason for both the high deposition rate and release flux of phosphorus. The preservation of phosphorus in the sediments of the pockmark area in the north Yellow Sea was also related to the escape of shallow methane, which could possibly enhance the formation of pyrite in cores. The higher DRP flux in the sediment-water interface would yield some ecological environment problems like regional eutrophication, which would have far-reaching ecological influence and should be thus worthy of more attention.

This study investigated the pollution characteristics of heavy metals (Cu, Zn, Pb, Cr, Cd, Hg, As) and polychlorinated biphenyls (PCB) in sediments across 4 typical intertidal zone areas in Zhejiang province and discussed the distribution, the potential ecological risks and their sources. The results showed that the contents of Cd, Hg, As, and PCB in surface sediments reached China's national first-class benchmark of marine sediment quality. The 42% of Cu, 9% of Zn, 3% of Pb, and 12% of Cr samples reached the China's national second-class benchmark. Only 1% of Cu and Zn samples dropped the China's national third-class benchmark. The integrated pollution degrees followed the order Yueqing Bay > Sanmen Bay > Xiangshan Bay > Hangzhou Bay, with a moderate pollution level in Yueqing Bay, and no pollution in other bays. The comprehensive potential ecological risks followed the order Yueqing Bay > Hangzhou Bay > Sanmen Bay > Xiangshan Bay, with a moderate risk level in Yueqing Bay and Hangzhou Bay, and a low risk level in Sanmen Bay and Xiangshan Bay. Cd was the primary potential ecological risk factor, who contributed for the potential ecological risk index (RI) by 63%, 54%, 58%, and 55% in Hangzhou Bay, Xiangshan Bay, Sanmen Bay, and Yueqing Bay, respectively. Domestic wastewater, agriculture, industrial production, and transportation were the main sources of heavy metals and PCB pollutions.

In the current study, we evaluated the effect of extreme low temperature on respiratory diseases in Lanzhou from January 1, 2013 to July 31, 2017 using a distributed lag non-linear model (DLNM) based on the daily data of meteorology and hospital visitsfor respiratory diseases.Age (≤ 15years, 16-45years, 46 -60years, ≥ 60years) and gender (male and female) modification were also performed. Results indicatedthe greatestlag effect of average daily minimum temperature (T_min) on relative risks (RRs)for respiratory diseases. The maximum RR value ranged from 0.89 to 1.41 and the response-effect curvewas V-shaped. At lag of 0~4d, the cold effect represented by extreme low temperature was the most significant. Atlag of 5~19d, a new peak appeared near T_min at 0℃, and the cold effect started to decrease, while the heat effect disappeared completely. At lag of 20~30d, the minimum RR value appeared when T_min was -10℃ and the peak value was near the temperature point of 0℃. Lag effect completely disappearedat 22d. Under extreme low temperatures, respiratory diseases showed long-term hysteresis and higherrisksforthe younger ages, while short-term hysteresis and lowerriskforthe older ages. As to the gender, males showed a longer lag effect than females.

This paper studied the effect of air pollution on the number of hospital visits made by children of different gender and age due to respiratory diseases in Lanzhou, as well as its seasonal variation. By collecting data on the concentration of air pollutants, i.e., PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ 8h, as well as the corresponding meteorological data and the outpatient data of visits made by children due to respiratory diseases at 3first-class grade three hospitals in Lanzhou between 2013 to 2017, the relationship between air pollutant concentration and daily outpatient visits made by children due to respiratory diseases and its lagging effect were analyzed using generalized additive model (GAM) to constrain the day of week effect, meteorological factors, holiday effect, and other confounding factors. During the research period, the average daily outpatient visits made by children due to respiratory diseases at 3first-class grade-three hospitals in Lanzhou was 387 person-times, ranging from 1 to 1413 person-times. According to the results of the single-pollutant model, the effects of PM_2.5, NO₂, SO₂, and CO all peaked on lag01; for every 10μg/m³ (1mg/m³ for CO) increase in their concentration, the excess risk (ER) and 95% confidence interval (95%CI) of visits of children for respiratory diseases were 0.245% (95%CI:0.127%~0.363%), 0.568% (95%CI:0.327%~0.808%), 1.661% (95%CI:1.022%~2.302%), and 2.245% (95%CI:1.610%~2.883%) respectively. The effects of PM₁₀ and O₃ 8h had no statistical significance across the lag phase. Analysis of different gender, age, and season indicated that, PM_2.5 has a slightly stronger effect on girls than on boys, whereas the reverse applied in terms of the effects of NO₂, SO₂, and CO; PM_2.5, NO₂, and CO affected children aged 6~14more significantly than those aged 0~5, and the reverse was true for the effect of SO₂; the effects of PM_2.5, NO₂, SO₂, and CO on outpatient visits were only significant in winter, and the effects of PM₁₀ and O₃ 8h were insignificant in all seasons. According to the results of the two-pollutant model, after adjusting 5 other types of pollutants respectively, PM₁₀ and O₃ 8h had no significant effect on the increase in outpatient visits of children for respiratory diseases; after adjusting PM₁₀ and O₃ 8h, all other pollutants had a significant effect on the increase in outpatient visits for respiratory diseases. Hence, it can be concluded that air pollutants (PM_2.5, NO₂, SO₂, and CO) in Lanzhou share a close relationship with the number of outpatient visits due to respiratory diseases, and that increments in SO₂ and CO concentrations are more likely to increase the risk of respiratory diseases in children. Moreover, gender, age, and season can influence the relationship between air pollutants and the number of outpatient visits due to respiratory diseases.

Concentrations of seven heavy metals were determined in the clams Meretrix meretrix collected from the northern coastal area of Dongying City in October, 2016, to explore the contamination characteristic of these metals. Bioaccumulation and its influence factors of the heavy metals by M. meretrix from sediment environment were discovered. Consumption risk for these clams was also evaluated using the single factor pollution index (P_i) and the target hazard quotients (THQ_s) models. Results demonstrated that the concentrations of Hg, As, Pb, Cd, Cr, Cu, and Zn varied as 0.009~0.019, 0.51~0.80, 0.25~0.76, 0.45~0.76, 0.43~2.46, 1.83~3.78, and 14.33~17.75mg/kg, respectively. Comparing with other coastal areas, the contamination of heavy metals was at medium level in the clams M. meretrix investigated in this study. The contamination of heavy metals was the worst in the clams from the sampling site S5 based on the metal pollution index (MPI) model. The highest bioaccumulation capacity in M. meretrix occurred for Cd, and the average biota-sediment accumulation factor (BSAF) was calculated as 455.13%. Among these heavy metals, only Pb presented a significant positive correlation between its BSAF value and total content in sediment, while the bioaccumulation of Hg and Cu were positively and negatively correlated with the fine grain size (particle size <63μm, FGS) and organic matter (OM) contents in the sediments, respectively. The THQ_s values indicated that a potential health risk will be mainly caused by the heavy metal As through a long-term clam consumption. Therefore, some effective measures should be taken to reduce the accumulation of heavy metals, especially the element As, in clams in order to protect consumer health.

Marine plastic debris pollution is a global environmental issue. Due to the persistence and universality of plastics debris pollution in marine environment, its impact on marine biodiversity has attracted a worldwide attention. In this paper, Relative Risk Model was applied to assess the potential ecological risk of marine plastic debris on Indo-Pacific humpback dolphin (Sousa chinensis) in Xiamen Bay. Four different sizes of plastic debris were defined as risk sources and S.chinensiswas defined as risk receptors.Spatial analysis tools in GIS were used to evaluate and quantify the ingestion risk of plastic debris on S.chinensisandits spatiotemporal distribution. The debris size and impacted area withhigh-risk types, as well as the drivers for high-risk were also identified. The results showed that different sizes of marine plastic debrishad a different potentialecological risk to S.chinensis, with small and medium plastic debris had a higher risk than that of large debris. The spatial and seasonal differences were significantin the ecological risk of debris on S.chinensis. Higher risks were found in summer and winter,this is mainly because of high debris loading due to intensive typhoon and tourism activities in summer, and astronger activity of S.chinensis in Winter. The highest riskswere found in the waters of Dadeng Island and Jiuyu Island in summer, while in winter the highest risks were found in the waters of south of Xiamen Western Seaand Jiuyu in Jiulong River Estuary in winter. The results can provide information to support the decision-making for the managementof S.chinensis conservation in Xiamen Bay.

In this study, the temporal variations of anthropogenic heat (AH) flux in China from 1985 to 2018 were studied by using the province depended non-renewable energy consumption and pullulation data from Chinese Statistical Yearbook. Based on the gridding population data and emission inventory of CO, the spatial distributions of AH fluxes over China were further investigated. According to the data of non-renewable energy consumption from different categories, the AH fluxes emitted from the industry sector, buildings, vehicles and human metabolism were respectively estimated. The results show that the AH flux in China has been increased continually since 1980s. The increase is more obvious in the period after 2000, but slows down during 2012 to 2016. In 2016, the national average AH flux in China is 0.442W/m², with the values for the industry sector, buildings, vehicles and human metabolism being 0.31, 0.072, 0.038, and 0.020W/m², respectively. For the spatial distribution, the AH flux values are obviously higher in eastern China than western China. Higher values usually occur in the Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta urban agglomerations. Some important megacities in other regions of China also have higher values. Moreover, the spatial distributions of AH fluxes from the industry sector are similar to those of economy activities and urbanization. For the AH fluxes emitted from vehicles, more of them are concentrated in the transport hub cities. Compared with other existing inventories of AH fluxes in China, the outputs of this study show higher AH fluxes in big cities, which better illustrates the significant effects of human activities on the emissions of AH.

Based on the MODIS land surface temperature (LST) product, Enhanced Vegetation Index (EVI) product and land cover data, the impacts of urbanization on seasonal variations of vegetation growth (ΔEVI) and surface urban heat island intensity (SUHII) during 2000~2015 for thirteen major cities in the Beijing-Tianjin-Hebei region were analyzed. The results are as follows:urbanization has negative impacts on vegetation growth (ΔEVI<0) in all seasons for the thirteen major cities, and the lowest ΔEVI (-0.131) was found in summer. The highest daytime and nighttime SUHII were also found in summer, and the values was 2.594℃ and 1.859℃, respectively. The average ΔEVI decreased during 2000~2015 with an rate of -0.0038/a, -0.0033/a, -0.0045/a, and -0.0018/a (P<0.01) for the growing season, spring, summer, and autumn, respectively (P<0.01). The daytime SUHII from 2000 to 2015 exhibited significant linear increase with a rate of 0.076, 0.093, and 0.106℃/a for growing season, spring and summer, respectively (P<0.01). The nighttime SUHII from 2000 to 2015 also exhibited significant linear increase with a rate of 0.05, 0.055, 0.049, 0.054, and 0.046℃/a for growing season, spring, summer, autumn and winter, respectively (P<0.01). The ΔEVI had significant negative correlations with all-time SUHII for all the thirteen cities in the Beijing, Tianjin and Hebei region (P<0.01), ranging from -0.959to -0.592. The maximum correlation coefficient between the daytime SUHII and ΔEVI was found in the growing season (-0.959), and the maximum correlation coefficient between nighttime SUHII and ΔEVI was found in the spring (-0.936).

This paper examined the issues of the non-linear relationship, mechanism and spatial heterogeneity between investment in technological innovation and environmental total factor productivity, using a city-level panel data with 280 Chinese cities from 2004 to 2015. It showed the following results:there was an inverted N-shaped relationship between investment in technological innovation and environmental total factor productivity, and two turning points were 7.722 (22.577 million yuan per year) and 9.610 (14913.17 million yuan per year), respectively. The effect of investment in technological innovation on the entry of external capital had negative impact on environmental TFP due to the pollution haven hypothesis, and the effect between the investment and external capital was 0.1363 while the effect between external capital and environmental TFP was -0.0065; investment in technological innovation could improve firms' pollution abatement technologies and increase environmental TFP, the effect between the investment and improvement on abatement technologies was -0.0277 while the effect between improvement on abatement technologies and environmental TFP was -0.0311; investment in technological innovation has also resulted in an increase in the scale effect, which efficiently changed the structure of production and enhanced environmental TFP then, the effect between the investment and changes of production structure was 0.0186 while the effect between changes of production structure and environmental TFP was 0.4346. In spatial heterogeneity, the negative effect of pollution haven due to the entry of external capital and spillover effect was significant in the central China, and insignificant in the west and northeast China, however, the paper found the positive effect of pollution haven in the east China but the effect was insignificant; the positive spillover effect of technology due to the investment in abatement innovation was significant in the east and west China, insignificant in the central and northeast China; the scale effect due to the investment in innovation and market demand was no different across spatial regions and positively significant. The paper suggested using strategies of spatial heterogeneity according to different mechanisms created by the investment in technological innovation.

Based on the input-output model, this paper explored the direct and complete energy consumption coefficient of different industries in Gansu province in 2007, 2010, and 2012, as well as the net input and output characteristics of the virtual energy in inter-provincial trade. The results showed that:From 2007 to 2012, the per capita virtual energy consumption and total energy production in Gansu Province showed an upward trend, with growth rates of 25.5% and 28.2%, 13.9% and 13.6%, respectively, and energy consumption growth rates was much higher than total energy production. From 2007 to 2012, the flow trend of Gansu Province's virtual energy had changed among industries significantly. Among them, the virtual energy in 2007 mainly flowed toindustry and transportation and warehousing, with values were 2957.41 and 23.3635million tons of standard coal, respectively. The trend was consistent with it in 2010, the values were 25.6392 and 30.9543million tons of standard coal. In 2012, the virtual energy mainly streamed to the construction industry and the wholesale and retail and other industries, with values of 36.9504 and 30.601million tons of standard coal, respectively. From 2007 to 2012, the gross of virtual energy in Gansu province increased by 28.9%, and the virtual energy in construction, wholesale and retail and other industries increased by 94.7% and 92.5%, respectively. While, in agriculture, industry, transportation and warehousing it decreased by 24.4%, 42.3% and 91.6%, respectively. From 2007 to 2012, the trade pattern of virtual energy in Gansu Province showed a net input-net output-net input trend, and the virtual energy principally streamed to the developed area with more energy gross, such as Hebei, Inner Mongolia, Shanghai and Shanxi, mainly by industry, transportation and warehousing, among them, industry, transportation and storage industry were the main output industries, while Beijing, Liaoning, Jiangsu, Fujian and Ningxia were the main input sources. Therefore, reducing the province's energy output and increasing the share of provincial trade input will be crucial for the sustainable development and utilization of Gansu's economy and energy.