In order to assess the effect of meteorological conditions on air pollution quantitatively and predict the air pollution potential, the Atmospheric Self-cleaning ability Index (ASI) was defined based on the prediction principle of city air pollution prediction system (CAPPS). Both computational methods of ASI using observational data of meteorological stations and the meso-scale modelling result were introduced. The analysis of ASI in China showed that the lowest ASI was located in Sichuan Basin and Talimu Basin in Xinjiang, and the highest ASI was located in Plateau, island and peninsula areas. The decrease of ASI and the increase of the low ASI days of a year were found in regions of Jing-Jin-Ji, Yangtze River Delta and Pearl River Delta from 1961 to 2017. The effect evaluation of air pollution prevention and control during the Beijing APEC conference using ASI showed that the AQI in Beijing decreased by 77% and the mean AQI of 11cities in Jing-Jin-Ji Plain decreased by 37% because of the emission reduction while the worst air pollution meteorological condition happened in 8^th~10^th Nov. 2014. An air pollution potential prediction system on extended and monthly scales, which can predict nationwide daily ASI of 40 days in advance, was set up based on the combination of the production of the extended and monthly dynamical climate model (DERF2.0) and the downscaling of WRF model. The historical simulation experiment showed that the system could forecast the process of heavy air pollution events 15days in advance in most cases, and the forecast accuracy depended on the extended and monthly dynamical climate model (DERF2.0) to a considerable extent.

Based on the air quality monitoring data collected in 40 cities in Yangtze River Delta urban agglomeration in 2016, this study presents the spatial-temporal variation of O₃ concentration in Yangtze River Delta urban agglomeration in 2016 via spatial interpolation, spatial autocorrelation analysis, and hotspot analysis. It shows that:1) with an average O₃ non-attainment rate of 8.8percent, O₃ has become the second major source of pollutants following PM_2.5; 2) the O₃ concentration is decreasing from summer, spring, autumn to winter, the monthly changing of O₃ concentration follows a pattern of "M", with two peaks in May and August respectively, and a valley in June due to the interruption of the plum rain season; 3) the O₃ non-attainment mainly occurs from April to September, which contributes 98.1% to the O₃ non-attainment days during the whole year with an average monthly rate of 17.3%; 4) the O₃ concentration shows an a general decrease trend from the northeast to southwest, and the line connecting Hangzhou and Ma'anshan highlights the difference between the highly polluted area in the eastern side of the line, and the less polluted area in the western side of the line. The cities around the Taihu Lake suffer from severest pollution. In geologically speaking, the spatial distribution of O₃ is approximately in accord with that of the economic development levels of Yangtze River Delta urban agglomeration; 5) the O₃ concentration follows the spatial agglomeration law. Owing to the impact of southeast monsoon, the hotspots of O₃ are primarily distributed in the eastern part of the Lake Cities from April to July, and later, move westward to Nanjing and its adjacent areas from August to September.

We analyzed the spatial distribution and variation trend of PBL SO₂ over China using the satellite retrieved data from the ozone monitoring instrument (OMI) sensor. In the long term scale, the SO₂ presented an obvious decline trend. The regional mean value has reduced 0.041DU (about 13.2%) from 2005 to 2016. The SO₂ showed an obvious periodic variation, the value was higher in winter and lower in summer. The smallest and largest value appeared in July and December with 0.246 and 0.404DU respectively. The wavelet analysis finding showed that the variation of SO₂ have primary period in 10months scale. In the spatial scale, there were 4 higher value regions over Circum-Bohai-Sea region, Sichuan Basin, Yangtze River Delta, and Pearl River Delta. The Largest value was up to 1.1DU over Bohai Rim Economic Zone. The higher value areas of the Circum-Bohai-Sea region in North China has been extended to the Yangtze River Delta region, with the southward extension to the Pearl River Delta. The SO₂ in the Sichuan Basin have higher values due to the influence of topography and weather characteristics. In the Tibetan Plateau and Northwest China, the SO₂ concentration was low, indicated the background value characteristics, the multi-yearly average SO₂ was about 0.05DU. There were obvious differences in the spatial distribution of variation trends of SO₂ over China. The range of variation was between -0.70 and 0.15DU. The gradual decreasing region of SO₂ appeared in high-value areas, such as Circum-Bohai-Sea region, Sichuan Basin, the Yangtze River and the Pearl River Delta. The largest reduction was about 61%, which reduced by about 0.55 and 0.45DU over Sichuan Basin and the Pearl River Delta from 2005 to 2016, respectively. The gradually increasing regions were mainly in the western and northern region, and the southeast coast excluding the Pearl River Delta. The maximum growth was about 0.15DU.

Synoptic analyses associated with the aerosol adjoint module of the atmospheric chemical modeling system GRAPES-CUACE are used to investigate characteristics of the atmospheric circulation, the formation and dissipation of air pollutants during a heavy PM_2.5 pollution episode from February 29 to March 6, 2016 in Beijing. The adjoint module is also applied to track the key source areas and sensitive emission period. Analyses reveal that the PM_2.5 concentration in Beijing exhibits remarkable daily variations and reach its peak at 20:00 BJT on March 4, and the observed PM_2.5 concentration attain 506.4μg/m³ at Haidian station. Beijing is controlled by the low pressure during the episode, with less influence of cold air, weak/calm winds, strong inversion of temperature, stable atmospheric stratification, low planetary boundary layer (PBL), facilitating the accumulation of air pollutants. The occurrence of a short-term PM_2.5 decrease is primarily caused by the 500hPa short-wave trough transit and the southerly jet in the PBL. Model results show that the PM_2.5 concentration at the target time of the pollution process in Beijing is affected jointly by the transport from the northeastern and southern regions of Hebei, Tianjin, and parts of Shanxi and Shandong. The peak PM_2.5 concentration at the target time in Beijing responses most quickly to the local emission source and most slowly to the Shanxi emissions. The cumulative contribution of emissions from Beijing, Tianjin, Hebei, and Shanxi to the PM_2.5 concentration in Beijing at the target time during the first 72hours is 31.1%, 11.7%, 52.6%, and 4.7%, respectively. Within 3 hours before the target time, the local emission dominates the PM_2.5 concentration in Beijing, with a contribution of 49.3%, but emissions from Hebei and Shanxi are dominant within 4h to 50h and within 50h to 80h before the target time, with contributions of 48.6% and over 50%, respectively.

Based on the observational data, upper air and ground surface synoptic field during 2014~2015, and NCEP/NCAR reanalysis data in December 2015, combined with WRF-CMAQ numerical model, the characteristics and the cause of the air pollution process in Dalian were analyzed. The results showed that there were 145 pollution days, accounting for 20%, and 35pollution processes in Dalian from 2014 to 2015. The upper air circulations during air pollutions were mainly northwest air flow field after the trough (accounting for 63%), and the southwest air flow field before the trough (accounting for 21%). The ground surface synoptic field were mainly in two types, which are uniform pressure field with weak wind (accounting for 68%) and intensive isobars with high-speed wind. The atmospheric stratification was stable, with weak average horizontal wind during 5air pollution processes in December 2015 in Dalian, which suppressed the dispersion of pollutant in the vertical and horizontal directions, leading to the deterioration of air quality. Results of the numerical model simulation showed that nitrate, ammonium and sulfate are the main components of aerosols during the pollution process. And the nitrate provided the first contribution and the most obvious increase during the pollution processes, which means the vehicle emission and coal-fired emission already had important impacts on the formation of urban pollution in Dalian.

An serious air pollution episode over Beijing and surrounding area have persisted from November 2 to 8, 2017. In order to monitor and analyze this air pollution, a remote sensing inversion of time series iterative algorithm (TSIA) was used to retrieval the aerosol optical depth (AOD) for the particle pollutants based on COMs1(Communication、Ocean & Meteorological Satellite-1) GOCI (The Korea Geostationary Ocean Color Imager) data. The core idea of TSIA is the surface reflectance variations is minimized by a reasonable assumption of aerosol changing quickly but earth's surface changing slowly over time. The results show that the AOD over Beijing and around area has a fairly good relationship with R² of greater than 0.89 compared with the ground-based measurements from Aerosol Robotic NETwork (AERONET). The high monitoring frequency of GOCI (once per hour in daylight) could capture the air pollution trends better from forming to dissipation, which can be of great assistance in climate change researches and environmental monitoring.

Based on the data of atmospheric extinction coefficient detected by Mie scattering lidar from June 2013 to May 2015 of Chengdu, it was found that there was a S-shaped transitional zone between aerosol extinction and molecular extinction above mixing layer, and sigmoid function was used to simulate this vertical distribution. By obtaining the heights of the upper and lower maximum curvature points of the function, a sigmoid algorithm for calculating the transition zone of particle boundary layer based on Mie scattering lidar was proposed. The results showed that, as to the atmospheric extinction coefficient in the transition zone and its vicinity, simulated profiles and measured ones maintained a significant correlation, and the correlation coefficients of the two in spring, summer, autumn and winter were 0.9971±0.0052, 0.9935±0.0167, 0.9979±0.0038 and 0.99895±0.0021 respectively (Passing the significance test of 0.05). Further researches indicated that there existed a good correspondence between the transition zone of particle boundary layer calculated by sigmoid algorithm and the inversion layer identified by sounding data in Wenjiang station.

Air pollution condition is affected by meteorological elements and emissions from air pollution sources. In order to evaluate the effect of air pollution control measures, we need to separate the contributions from air pollution sources. In this study, the KZ filter was used to decompose the time series of three pollutants including O₃, PM_2.5 and PM₁₀ as well as time series of several meteorological factors into long-term, short-term and seasonal components. Data of air pollutants were collected from six air quality monitoring sites in Tianjin during 2015~2017. The contribution of each component to the total variance of the original air quality data was calculated. Stepwise regression was used to establish the relationship between air pollutants (O₃, PM_2.5 and PM₁₀) and meteorological variables for each time scale. Our results showed that seasonal component contributed most to the total variance, followed by short-term component. Temperature and relative humidity were the major factors affecting seasonal and short-term changes of O₃. Temperature was positively correlated with short-term component. Relative humidity was negatively correlated with the seasonal component of O₃; Wind speed, air pressure and precipitation were negatively correlated with particle concentrations at short-term and seasonal time scales. Relative humidity was positively correlated with them. Temperature was positively correlated with short-term component of particles, and was negatively correlated with seasonal component. Long-term concentration of PM₁₀ showed a downward trend after removing the effects of meteorological factors. The concentration of PM_2.5 increased in early 2017, and for the rest of the study time periods, its concentration showed a downward trend. The long-term concentration of O₃ was increased during the studied years. We can conclude that the effect of particulate pollution control measures was significant. However, the pollution of O₃ was aggravated.

We characterized the temporal variations of visibility (Vis), relative humidity (RH) and liquid water profile (LPR) during low visibility periods based on the visibility, cloud and microwave-radiometer-detected liquid water content data provided by the national basic meteorological station in Guangzhou from November 2013 to April 2014. Results showed that the occurrence frequency of Vis<10km was 66.37%. Vis ≤ 1km happened when RH ≥ 95%, and 1km 90%. Vis>5km did not occur when RH>95% and Vis>15km never happened at RH> 90%. Low visibility events tended to happen more frequently in the morning than in the evening and seldom occurred during noontime. This was consistent with the variations of LPR in the corresponding period, indicating that low visibility events may correlate positively with the high liquid water content in the lower atmosphere. The integral liquid water content of the atmosphere was generally high when Vis < 10km. The high liquid water content exceeding 0.02g/m³ was normally observed in the atmosphere below 3km, with the maximum liquid water approximately appeared at 1550m height. The liquid water content was relatively low in the case of Vis ≥ 10km, which seldom exceeded 0.02g/m³ and the maximum value of which was usually observed at a height of approximately 2km. Less than 50% of the low visibility events in Guangzhou was introduced by the formation process of low cloud (or low cloud reaching the ground to form fog). When Vis ≤ 1km, LPR was observed to be nearly zero as no liquid water content was detected by the microwave radiometer. Simultaneously, it is worth noting that the ground-level aerosol loading was quite high (PM_2.5>88.3μg/m³) when RH > 95% and the atmosphere was approaching saturation condition, suggesting that low visibility events (Vis ≤ 1km) in Guangzhou could be attributed to the combination of fog and haze. This highlights the need for comprehensive analysis of the liquid water content from microwave radiometer measurements, relative humidity, and particle mass concentration in order to further distinguish haze pollution from fog and/or mixed fog and haze phenomena.

A model for estimating air pollutant emissions from cement industry was developed based on emission factors for the greater Beijing-Tianjin-Hebei region. The estimated emissions based on the model were used to analyze of current status and emission characteristics of the major air pollutants, including SO₂, NO_x, and PM from cement industry in 2016. The results showed that the emissions of SO₂, NO_x and nonfugitive PM from cement industry were 3.2×10⁴t、23.9×10⁴t、9.7×10⁴t, 24.1%, 18.2%, 27.2% less than which in 2015, respectively. Fugitive PM contributes to 45.4% of the total PM emissions, and it is necessary to enhance colleting the fugitive PM emissions. Shandong and Henan are the greater contributor of SO₂, NO_x, PM, PM₁₀ and PM_2.5 emissions from cement industry. More phasing out of abundant cement producing capacity in these two provinces should be a key measure to reduce their emissions. The cutting-edge technologies such as high efficiency nitrogen and sulfur removal technology, collaborative disposal technology and high efficiency baghouse filter should be considered reduce the emissions from the New Dry Process clinker production, and the pollution control in the grinding stations also need to be strengthened.

Based on the spatial correlation and spatial heterogeneity, the SLM-STIRPAT model, SEM-STIRPAT model and GWR-STIRPAT model were constructed to measure and analyze the driving factors of vehicle transport carbon emissions in Beijing-Tianjin-Hebei region. The results showed that:There were significant spatial correlation and spatial heterogeneity in vehicle transport carbon emissions in Beijing-Tianjin-Hebei region. The population size and had a positive impact on the vehicle transport carbon emissions. The per capita GDP had a positive impact on the vehicle freight transport and total vehicle transport carbon emissions, had a negative impact on the passenger transport carbon emissions. The urbanization level had a positive impact on the vehicle transport carbon emissions. The added value of the tertiary industry had a positive impact on the vehicle passenger transport and total vehicle transport carbon emissions, had a negative impact on vehicle freight transport carbon emissions. Population size had the most significant impact on vehicle transport carbon emissions in Zhangjiakou. The per capita GDP had the most significant impact on vehicle transport carbon emissions in Qinhuangdao and Cangzhou. The urbanization level had the most significant impact on the vehicle transport carbon emissions in Qinhuangdao. The added value of the tertiary industry had the most significant impact on the vehicle transport carbon emissions in Qinhuangdao.

A complete numerical model was developed for the dust removal process in the two-stage electrostatic precipitator (ESP). Numerical simulation method was used to study velocity distribution, particle charging characteristics, particle moving tracks and other physical processes which were difficult to measure directly. The electric field was analyzed using Poisson equation, current continuity equation and homogeneous electric field equation. Fluid flow was elucidated using N-S equation and the standard k-ε turbulent model. Particle tracks were described using Lagrangian method. The accuracy of the numerical model was verified by comparing the numerical results with the experimental data of the cross-sectional velocity and the particle removal rate. Numerical simulation results showed that the fluid flow distribution in two-stage ESP was sensitive to the inlet wind speed. The proportion of charge with different charging methods was determined by particle diameter. And the particles of different sizes had different dominant charging methods. Moreover, the approach of particles to plates was caused by the interaction of the electric force and the drag force in pre-charger, while the approach in dust collection part was dominated by electric force. It was also found that the inlet velocity influenced the particle tracks by changing particle advance speed and internal flow field.

A new solid amine was prepared as adsorbent of SO₂. For comprison, the adsorption efficiency of several kinds of solid amine adsorbents with different structure and pore size were investigated. In addition, the mechanism of SO₂ adsorption and the properties of the desorbing were discussed. The results show that the solid amines have a high SO₂ adsorption capacity. The residual amount remaining in the solid amine is measured to be low after 20 times of adsorption-desorption cycles. The desorption of SO₂ was significantly affected by the type of molecular sieve structure and pore size of the solid amines. The adsorption efficiency is decreased by reducing the pore size of molecular sieve. However, the residual of SO₂ was decreased with the increase of SiO₂/Al₂O₃ content in solid amine. The effects of CO₂ and NO_x on the solid amine SO₂ adsorption were also studied. The results showed that CO₂ had little effect on the adsorption of SO₂ in the solid amine, but the adsorption of SO₂ was interfered byNO_x. Investigation on the chemical composition of desorption residuals show that the components of desorption residuals of the solid amine adsorbent is similar to that of the liquid amine thermal stabilizers. Because of its high operating temperature, the solid amines could be easily regenerated.

Electrochemical heterogeneous catalytic ozonation (E-catazone) process was studied for treating amantadine wastewater, which was of high COD, high salinity and nonbiodegradable. The amantadine removal efficiency of E-catazone process was compared with catalytic ozonation (Catazone) and electrochemical oxidation (EO) processes, Besides, the effects of current density, pH and ozone concentration on the amahadine treatment efficiency were further investigated to obtain optimized experimental conditions. Electro-catalytic ozonation obtained 62% of the COD removal efficiency and 44% removal of TOC under pH 12.5, current density 15mA/cm², O₃ flow rate 0.4L/min and O₃ concentration 60mg/L, The performance was significantly better than that of Catazone (COD 44%, TOC 29%) and EO (COD 13%, TOC 17%), E-catazone process demonstrated strong oxidizing power and fast oxidation rate, and the pseudo-first order of COD removal rate constant k was 1.81times and 8.22times of Catazone and EO, More importantly, the E-catazone could improve the biochemical properties of wastewater efficiently and rapidly, and increased by about two order of magnitude. The results showed that the E-catazone was a potential advanced oxidation technology, which could realize high efficiency, fast removal of organic pollutants and improve the biodegradability of wastewater.

This paper investigates the factors that influence the preparation of polysilicate aluminum ferric coagulant using solid wastes which containing and their microstructure and morphology. Four factors (basicity, nAl:nFe, polymerization temperature and reaction time) and three levels of response surface experiments were carried out, which regarded the transmittance as the evaluation index. Results showed that the optimum scheme when the basicity was 0.5, the nAl:nFe was 1.38, the polymerization temperature was 39.2℃, and the reaction time was 1.36hours. At the optimum theme, the predicted value of transmittance reaches 90.24%, and the relative error of all the verification experiments was 1.20%, which indicated the RSM optimization model is reliable. X-ray diffraction test indicates the formation of sodium chloride and new amorphous polymers from leachate. The infrared tests illustrates that a large amount of nonionic complex state (such as metal-hydroxyl groups) occurs between polysilicate acid and Al³⁺ and Fe³⁺. The TEM micrograph shows that the product presents a three-dimensional reticular structure, with high level of aggregation and branches. The thermogravimetric analysis shows that a substantial numbers of bound water and hydroxyl group were lost below 400℃, and the main chemical bonds in the products were broken at about 700℃. Strong endothermic peaks were presented correspondingly in the DSC diagram. The indexes test revealed that the coagulant presents good performance.

In this manuscript, the Cu-NWs conductive microfiltration membrane, obtained via phase inversion method, was prepared by dosing moderate Cu-nanowires (Cu-NWs) into conventional polyvinylidene fluoride (PVDF) casting solution. The filtration and conductivity properties of obtained conductive membrane were characterized. Finally, the efficiency of pollutant removal and membrane fouling behaviour were investigated in a membrane bioreactor (MBR) system with the prepared conductive microfiltration membrane for long-term operation. It provided a new route for the stable operation of MBR system with low cost. With dosing a certain amount of Cu-NWs, the membrane flux of prepared conductive microfiltration membrane was 721.9L/(m²·h) and its surface contact angle was 57.9°, which were better than those of commercial PVDF microfiltration membrane. The initial potential, ohmic resistance and activation resistance were 315mV, 2.4Ω and 6.9Ω, respectively. The scanning electron microscope (SEM) observation showed an excellent conductive network in the active layer of membrane. The removal rates of the established MBR system with prepared conductive microfiltration membrane were 91.5% for chemical oxygen demand (COD), 99.3% for NH₄⁺-N, 76.3% for total nitrogen (TN) and 76.2% for total phosphorus (TP), which were higher than those of the control MBR system. Over 146-d operation, the TMP was always lower than 25kPa and the membrane cleaning was not needed. The Fourier transformation infrared spectrometer (FTIR) analysis showed that the main contaminants on the membrane surface were proteins and polysaccharides, and the content of EPS on membrane surface was much lower than that of commercial PVDF membrane. The novel Cu-NWs conductive microfiltration membrane with good stability, durability and antifouling property showed a promising prospect.

To realize the quick and accurate measurement of the dissolved oxygen concentration (DO) in wastewater treatment process, a novel chaos-fireworks algorithm (FWA) based hybrid optimization algorithm was proposed and a neural network on-line soft-sensor model was built based on the improved algorithm. According to the property of the data collected from wastewater treatment process, a new measure of similarity degrees between samples was defined to extract more responsive modeling data. In the novel algorithm, a modified two-level sinusoidal chaotic mapping was defined and the initial members of FWA were well selected by utilizing the ergodicity of chaos. As a result, the quality of the initial population in standard FWA was improved. Next, the search mechanism of FWA was modified by introducing chaos optimization algorithm. The optimization procedure was divided into two phases and the population was divided into two subpopulations according to the predefined criterion. Test results confirmed that the improved FWA had higher convergence speed and convergence accuracy. The novel soft-sensor modeling method and the sample data extraction method was used to build a soft sensor model for real-time measuring DO in wastewater treatment process. Application results indicated the root mean square error and the root mean square error of this model were 0.0175 and 0.0118 respectively, it had good generalization ability.

A self-developed hydrodynamic cavitation device with combinations of circular multi-orifice plates with Venturi tubes from the Hydraulics Laboratory at Zhejiang University of Technology was used to kill pathogenic microorganisms in raw water. Its effect was manifested by detecting the killing rate of E. coli and total colony count. The killing rates of E.coli and total colony count under the different working conditions were detected by plate counting method. The effects of cavitation number, orifice arrangement, orifice number, cavitation time, raw water percentage, throat length on the killing rates of pathogenic microorganism were analyzed. The experimental results showed that increasing orifice velocity and orifice number, prolonging cavitation time, lowering cavitation number, increasing the number of orifices, improving orifices arrangement and choosing appropriate raw water percentage and extending the throat length, could increase the killing rates of E.coli and total colony count. Hydrodynamic cavitation has potential application prospect as a new technology with no disinfection by-products, safe and high efficiency.

Microalgae and bacteria communities related to sewage treatments were cultured with activated sludge from a brewery. And then, they were used to treat sewage from the brewery under two experimental conditions:Treatment 1 (Filtered and sterilized sewage) and Treatment 2 (filtered but unsterilized sewage). Compositions of microalgae and bacteria communities were analyzed during the experiments. After 20 days incubation, microbial community structures notably changed in all treatments. Chlamydomonas rhinella and Chlorella sp. became dominant bacteria communities in Treatment 1and Treatment 2, and the abundances of unidentified OPB35increased significantly. But Lysobacterium decreased significantly in two treatments. The removal rates of chemical oxygen demand (COD) in Treat. 1and Treat. 2were 73.7% and 67.2%, respectively. What is more, microalgae grew well in the two treatments. Results showed that microalgae communities significantly influenced bacteria community compositions in Treat. 1and Treat. 2and there were no significantly differences in the removal efficiencies of COD_Cr in two treatments.

The inactivation effects of multi-drug resistant bacterium E. coli CGMCC 1.1595against tetracycline and ampicillin from secondary effluent by light irradiation and photocatalysis with graphite carbon nitride (g-C₃N₄) were studied. The results showed that the higher irradiation power of the mercury lamp (100/300/500W) with higher irradiation intensity could lead to higher inactivation efficiency. Under the inactivation by 500W mercury lamp irradiation of 60min, the inactivation rate of E. coli CGMCC 1.1595was 0.41log by ultraviolet A (UVA)-visible light (300~579nm) irradiation, and the inactivation rate was up to 1.31log by g-C₃N₄ photocatalysis. The contribution of g-C₃N₄ to the UVA-visible light inactivation was 61%~69% compared to that without g-C₃N₄ catalyst, while the contribution of g-C₃N₄ to the visible light inactivation was 60%~79%. The significance of the reactive oxygen species (ROS) and hole (h⁺) for the g-C₃N₄ photocatalytic inactivation of E. coli CGMCC 1.1595were also investigated, with the activity order as·OH >·O₂^- > H₂O₂ > h⁺ > ¹O₂. Hydroxyl radical (·OH) was a leading contributor to the irradiation, followed by·O₂^- and H₂O₂.

In this paper, molten NaOH-KOH mixture was selected as the medium for the destruction of pesticides, with the 2,4-dichlorophenol as an example. The effect of temperature, hydroxide amount and reaction time were investigated. The equal molal weight showed a best dechlorination rate and the increased temperature as well as hydroxide amount can promoted the dechlorination reaction. When the temperature of 200℃, reaction time of 180min and hydroxide amount of 20g, the dechlorination efficiency acquired 80.1%. The FTIR spectra demonstrated the cleavage of benzene ring and C-Cl bond, leading to the generation of intermediate products. Gases like HCl was restrained by the molten salt medium to form chlorine salt, according to the XRD patterns.

In this study, sewage sludge from a waste water treatment plant in Shenzhen was used for pyrolysis to investigate the characteristics of generated particulate matter (PM) and the change of 8heavy metals. The results showed that the PM production rate peaked twice at 400~600℃ and at the first 30minutes holding at 1000℃, respectively. The thermal volatility of the 8heavy metals was as follows:Cd > Zn > As > Pb > Mn > Ni > Cu > Cr. And the enrichment capacities of the 8heavy metals in the PM followed the order:Pb > As > Mn > Zn > Cd > Ni > Cr > Cu. The volumetric heavy metals concentration generally showed an increase trend with the pyrolysis process. However, Zn and Cd decreased after peaking at the stage of temperature rising (before 1000℃). The research suggests that the heavy metals enriched during sludge pyrolysis and the generated PM exceeds the standard value. Therefore, the exhaust PM removal device is necessary.

Two different sewage sludge composting products (with and without biochar) were applied in field to study short-term impacts of their application on the greenhouse gases (CH₄, CO₂ and N₂O) emission from soil. The results indicated that N₂O emissions mainly occurred in the first three weeks, with the emission amount accounting for 87.9%~95.6% of the total emissions during the observation period. The emission amount of N₂O increased with the application amount of compost (P<0.05), and N₂O emission from bare land was higher than that of crop plants treatment. The application of sludge composting can lead to the reduction of the N₂O emissions from soil, and the N₂O reduction amount increased with the increase of the fertilizing amount (P<0.05). CH₄ emission fluxes showed negative values in the early and late stages of the experiment, indicating that soil could adsorb CH₄. The absorption of CH₄ took place mainly after 18 days, accounting for 52.1%~66.7% of the total absorping amounts. The absorping amount of CH₄ in soil with biochar compost was 35.2% to 62.2% less than that in soil without biochar, and higher absorping amount of CH₄ appeared in bare land when compared with the land with planting crops (P<0.05). CO₂ emissions mainly occurred after 18days, accounting for 50.5%~61.8% of the total emission. The planting crops can promote the CO₂ emission in soil, which was 1.34~1.57 times that of the bare land. Thus, it can be speculated that land application of compost was a weak sink of CH₄ and a source of N₂O and CO₂ emissions during the observation period. The application of sludge composting can lead to the increase of the emissions of N₂O and CO₂ in soil. Sludge compost with biochar in short-term could reduce the N₂O and CO₂ emissions from soil, and the biochar played an important role in reducing the greenhouse gas emissions, as the emission amounts from soil with biochar compost was 20.41% to 62.51% less than that in soil without biochar.

China is the world's largest consumer of rubber, the annual production of more than 400million waste tires. Pyrolysis of waste tyre is a recycling route with high value-added and environmentally friendly. The higher color of dye wastewater has a serious impact on the ecological environment. In this paper, H₂SO₄ and NaOH were used to modify the pyrolytic carbon black of waste tire. The experimental results showed that when the ratio of carbon black to H₂SO₄ was 1g/15mL, the best decolorization rate of acid lake blue solution was obtained over HBC. Also, NBC obtained with the ratio of carbon black to NaOH 1g/10mL was good for treating basic lake blue solution. The stronger the acidity of the solution, the better the decolorization effect of HBC on the acid lake blue solution. On the contrary, the stronger the alkalinity of the solution, the better the NBC on the basic lake blue solution. In addition, the adsorption process of acid lake blue over HBC and alkaline lake blue over NBC was very close. The whole adsorption reaction was very fast. After 20min, the adsorption equilibrium was basically reached. The adsorption process of acid lake blue over HBC and alkaline lake blue over HBC conform to the pseudo second-order kinetic equation. The properties of scanning electron microscope, infrared spectrum and specific surface area of solid materials before and after modification were analyzed.

According to the cradle-to-gate life cycle evaluation method and taking into account the environmental impact distribution of concrete recycling, this research studies on properties and environmental impacts of repeated recycled aggregate concrete, and the optimum number of repeated regeneration of concrete is optimized on efficiency function method. The results concluded that, the slump, strength and electric flux decreased with cycles of repeated regeneration of concrete increasing, the 28d compressive strength 33.3MPa after 3repeated cycles, which arrived the design strength requirements. Compared with ordinary concrete, the slump decreased by 38.9% and electric flux increased by 85.7%, respectively; The ecological efficiency of concrete material increases with the repeated cycles increasing, the values of GWP, CED, and CMR of concrete materials are reduced with the increase of the repeated cycles increasing, The reduction variation from high to low is:CMR > GWP > CED; Taking into account the slump, the compressive strength, the electrical flux, the GWP, the CED, and the CMR in four concrete mix scenarios, the total efficiency coefficient of concrete from high to low is:the first generation recycled concrete > the second generation recycled concrete > the third generation recycled concrete > ordinary concrete.

In the present study, cyanide tailings were used as raw materials for preparing of iron-carbon micro-electrolytic fillers through coal-based direct reduction process. The fillers were used to treat methyl orange solution. The effects of calcination temperature, calcining time and coal dosage on the degradation of methyl orange were studied. The results showed that the fillers presents the best performance for removing methyl orange, which prepared under the conditions of calcination temperature 1250℃, calcination time 60min and coal dosage 30%. Increasing the amount of filler and reducing the initial pH of the solution facilitates the removal of methyl orange. For the treatment of 400mL methyl orange solution with a concentration of 100mg/L, the removal rate of methyl orange was close to 100% with 2.0g filler under acidic conditions when the treatment time was 30min. XRD analysis showed that the main crystalline phase in the filler prepared under optimal conditions was zero-valent iron. SEM analysis showed that the sizes of the zero-valent iron particles in the filler were all below 50μm, and the zero-valent iron and residual carbon constituted the micro-electrolytic filler.

Reduction of dissimilatory Fe(Ⅲ) by humic-reducing microorganisms (HRMs) from different composts was conducted. Results showed that the capacity for reduction of dissimilatory Fe(Ⅲ) by HRMs was ranked in the order protein-rich compost > cellulose-rich compost > lignin-rich compost. The result of correlation showed that Leucobacter、Clostridium sensu stricto and Sporosarcina were significantly associated with the Fe(Ⅲ) reduction. It was indicated that dissolved organic nitrogen was the primary micro-enviromental factors significantly driving the variation of these key HRMs by Redundancy analyses (RDA). Finally, based on the relationship between the mico-enviromental factors and HRMs, this work proposed a regulating method to enhance the growth of the key HRMs during composting. This study not only investigated the influencial factors of HRMs in compost deeply, but also had ecological significant in the study of waste biogeochemical process.

This study was conducted to investigate the effect of Rice hull ash (RHA) and rice hull biochar (RHB) on the bioavailability of rare earth elements (REEs) in the acidic soil. RHA and RHB were mixed into the artificially polluted soil at 0 (W/W), 5% (W/W, and 10% (W/W), respectively. pot experiments were conducted to assess the bioaccumulation of rare earth elements (REEs) by Carrot and chrysanthemum, which sequential extraction was used to analyze the change of REEs' fraction in the soil. The results of pot experiment indicated that the acid extractable of REEs decreased 31.56%, and 19.915% in the soil with 10% RHA and 10% RHB, comparing with the control group. Furthermore, the uptake of REEs by Carrot and chrysanthemum reduced 98.08% and 93.41% in the soil amended by 10% RHA, and decreased 68.61% and 66.75% with 10% RHB. In short, the addition of RHA and RHB can significantly decrease the bioavailability of REEs and restrain the plant's enrichment. Moreover, the amendment effect of RHA was better than the RHB, so the ash of crop straw, as a kind of convenient and effective soil conditioner, need to be valued application on the contaminated soil.

With the social and economic development since China's economic reform back in late 1970s, the generation of municipal solid waste (MSW) in China's urban areas is remarkably increasing along with the rising of living standards of Chinese residents. The proper management of MSW is one of the most important environmental issues faced by all levels of Chinese government. This study collected data of waste generation and treatment between 1979 and 2016 from government statistics and literature, analysed the evolution of temporal and spatial characteristics of MSW discharge and treatment in urban China, and established a national and regional MSW composition inventory. The results showed:(1) the MSW generation in urban China increased significantly to 204 million metric tons in 2016, and the main component was food waste. The national safe treatment rate for urban MSW had reached 96.6% with a transition to use combustion as primary treatment method instead of landfilling. (2) Temporal and spatial differences existed among different regions of China in urban MSW generations, growth rates of generation, MSW composition, safe treatment rates and capacity. Given varied local conditions, governments at different regions need to make effort to raise the levels of MSW reduction and utilization and make up for the safe treatment gap by following the national waste management plan.

Sanitary landfilling method was the main way to deal with municipal solid waste in China. On the basis of the theory and analysis framework of life cycle assessment, the life cycle analysis of municipal solid waste disposal in Nanchang sanitary landfill was conducted with the aid of eFootprint software in order to find out the outstanding environmental impacts and reasons of various treatment processes and propose targeted improvement. The results showed that the main environmental impact types of sanitary landfills were global warming (GWP), primary energy demand (PED), resource depletion-water (WU), acidification (AP), photochemical ozone formation (POFP), Ecotoxicity (ET), and freshwater eutrophication (FEP). The distribution of electricity surplus as a by-product contributed to the reduction of the potential value of various environmental impact indicators, among which, the most prominent was PED, followed by WU. The most prominent type of environmental impact in the collection and transportation process was POFP, followed by ET, PED, and FEP. The use of diesel transporters should be reduced and energy-saving environmentally friendly or clean energy vehicles should be used moderately in this process. The environmental pollution caused by the sanitary landfill process was the largest. The most prominent environmental problem in this process was AP, followed by GWP, PED, FEP and ET. The landfill gas collection efficiency should be increased by improving the process and clean energy should be used to reduce diesel use in this process. The surplus power generated by landfill gas achieved positive environmental benefits after energy recovery. The efficiency of landfill gas collection and combustion electricity production need to be enhanced in this process. The environmental impact of the leachate treatment process was relatively small, mainly represented by WU and FED. It was necessary to optimize the upgrading process while focusing on energy conservation, and to improve the existing drawbacks of the disposal process and remove hidden dangers.

Based on system dynamics through literature analysis, spot investigation and questionnaire results, the study of modeling and simulation of environmental benefit of Building Waste Resource recovery is carried to provide the favorable policy of lifting of environmental benefit to promote the sustainable development of building waste resource recovery. Through the scenario analysis of the environmental benefit modeling, it comes to the conclusion that the environmental benefit is in optimal state with 50yuan/t~60yuan/t of fine for illegal emission unit, about 30yuan/t of landfill charge, 15km~25km of distance of building waste to the center of resource recovery treatment and 25yuan/t of subsidy of resource recovery. At the same time, the government should improve the level of building waste related laws, cultivate the awareness of relevant personnel on-site recycling, and promote relevant research and development, in order to promote the environmental benefits of building waste resource recovery.

A nation-wide e-waste recycling system has been established based on planned capacity for self-sufficiency at the provincial level in China. However, due to the reliance on the informal collection network to collect waste product from consumers to the certified recycling plants, there was a mismatch between the planning intention and the real spatial pattern of e-waste flows. With data published by Ministry of Environment Protection in 2014 and 2015, we used hierarchical cluster analysis to identify the regional market blocks with intensive linkages of e-waste flows among all provinces. The result showed that (1) the collection rate was more stable at the regional level than at the provincial level; and (2) significant regional disparity existed among different regions. In conclusion, the policy implications were proposed to optimize the spatial pattern of e-waste recycling in China by addressing the potential impacts of different governance structure dominated by the producers or the recycling corporations.

Promoting municipal solid waste classified collection and resource utilization helps to facilitate the development of resource-saving and environment-friendly society. This paper reviews the development of China's municipal solid waste classification, collects the endeavours done by national and local authorities in the promotion, and extracts obstacles and bottlenecks during the process and countermeasures. This paper concludes that China's municipal solid waste classification has undergone three stages identified as begining (1990s), pilot exploration (2000~2015) and rapid development (2016 to now). At present, a highly operative waste classification method, propaganda way fused with Internet+, practical regulations and a progressively improved circulation chain (classified collection-classified transportation-classified treatment) are gradually adopted by national and local authorities to promote municipal solid waste classification. Even the classification of municipal solid waste is gradually progressing towards marketization. China will embark on a feasible, reproducible and promotional model of municipal solid waste classification. In the future, it is of great significance to rapidly promote the municipal solid waste classification in China by strengthening public participation and responsibility to recover, introducing more specific and highly operative implementation plans, emphasizing the classification education of school children, and making full use of domestic scavengers.

The study selected the ornamental plant remediation system as the study object, discussed the effects of the elevated CO₂ on the Cd and HHCB accumulation efficiency by Bougainvillea spectabilis, and analysed the ecological function by detecting the rhizosphere bacteria number, enzymatic activity, and organic carbon. Results showed that the combined Cd and HHCB contamination under elevated CO₂ showed no obvious inhibition function to the growth of the plant. Especially the elevated CO₂ treatments (750μL/L) significantly facilitated the plant growth and contaminant accumulation, furthermore, the rhizosphere bacteria number reached the maximum. Urea enzymes activity showed significant difference under the different treatments. The addition of HHCB and the elevated CO₂ facilitated the organic carbon in the rhizospheric soil. In summary, Bougainvillea spectabilis has potential to be used for remediating the combined Cd and HHCB contaminated soil remediation under elevated CO₂.

Understanding the characteristic of source strength of the microbial gene marker is the key for quantitative analyzing the microbial contamination from different sources. In this study, the source strength of human-(qHS601F/qBac725R), porcine-(Bac41F/Bac163R), cattle-(BacB2-590F/Bac708Rm) and poultry-specific(qC160F-HU/qBac265R-HU) bacteroides primers were explored by qPCR method, and then quantitative analysis of the source and level of microbial pollution in Xijiang river in Guangdong province. The results showed that the source strength of different specific bacteroides primers was human(qHB) > porcine(qPB) > cattle(qRB) > poultry(qCB). The concentration of DNA had little effect on source strength of each primers. The selected target area was generally contaminated by human, pig, cattle and poultry feces. The concentration of human, porcine and poultry-specific primers were increased slowly from upstream to downstream in the main stream. In the tributary, the mean concentration of human-, porcine-and poultry-specific primers were increased 1-order magnitude compared to the main stream. qRB had little change in different section of the river. This suggests that the pollution of domestic sewage, porcine source and poultry excrement in the downstream was more serious. The influence of cattle source pollution was not significant. Statistic analysis showed that human-specific premier had a significant correlation with traditional fecal indicator bacteria in the tributary which had high level of fecal pollution(FIB)(P<0.05). It reflected that human source was the major reason for the high concentration of FIB, and human feces was the persistent pollution source.

The spatial distribution of Microcystis and microcystin in Haihe River during water bloom were investigated using quantitative real-time PCR (qPCR) and ELISA techniques. Microcystin synthetase gene (mcyD) and PC-IGS fragments were used as the target the total microcystin population and the potential microcystin-producing subpopulation. The results showed that microcystin existed as a mixed population of potentially toxic and non-toxic genotypes in Haihe River. There was significantly spatial variation in the abundance of microcystin-producing Microcystis. The abundance of microcystin-producing Microcystis subpopulation was ranged from 1.16×10⁴ to 2.48×10⁷ copies/mL and the ratio of its abundance to total microcystin varied from 4.25% to 28.59%. The peak value of microcystin was site point 8, which 1mL water contained 195.51μg microcystin in Microcystis algae cells and 0.97μg/L in water. To sum up, total abundance of Microcystis remained a high level in Haihe Tianjin region. The toxin of Microcystis showed various among different sampling sites. The most significant impact factors for Microcystis' abundance was pH value. However, the content of microcystin is not upon the value of WHO's threshold. But the intercellular toxin in a given volume of water remains a high level, which may cause the potential risk to the ecosystem of down flow estuary.

The characteristics of DOM, the variation of bacteria and fungi in the decomposed process of H. verticillata and P.malaianus were studied under four temperatures (5, 10, 20 and 35℃). The results showed that the remaining biomass of H.verticillata were 59.13%, 43.91%, 32.61% and 29.57%, the remaining biomass of P.malaianus were 69.13%, 51.3%, 30.8% and 29.57%. The concentration of C, N was promoted by rising temperature, and there was no obvious effect on P(P>0.05). Two humic-like components (C1and C2) and one protein-like component C3 were identified in H.verticillata. Three humic-like components (C1, C2 and C3)were identified in P.malaianus. The variation of DO and CDC in the decomposed water were promoted by temperature. During 0~16d, the main bacteria involved in the decomposition of H.verticillata and P.malaianus were Proteobacteria and Bacteroidetes respectively. During 16~68d, the main bacteria involved in the decomposition of H.verticillata and P.malaianus were Phylum Firmicutes and Proteobacte respectively. The temperature had no obvious effect on bacteria community structure, and Ascomycetes was the major fungi during decomposition.

Ebullition is one of the main pathways for CH₄ emission. To quantify CH₄ ebullition flux and its ratio to total CH₄ emission flux over algae zone of Lake Taihu, floating chamber method was utilized in this study in the Meiliang Bay of Lake Taihu during spring and summer time. The results showed that daytime CH₄ ebullition flux was obviously higher than that of nighttime in both spring and summer seasons. The mean CH₄ ebullition flux and its ratio to total CH₄ flux in spring were 1.843nmol/(m²·s) and 31.2% respectively and that in summer were 104.497nmol/(m²·s) and 68.6%. The results indicated that the dominant CH₄ emission pathway was diffusion in spring and different from spring, ebullition played important role in summer. Temperature (air temperature, surface water temperature, and sediment temperature) and air pressure were significantly correlated to CH₄ ebullition emission at hourly and daily scale. The CH₄ ebullition emission increased exponentially with increasing temperature and increased linearly as air pressure decreased. This study can provide important basic data for accurately estimating total CH₄ emission in Lake Taihu basin and clarifying the contribution of CH₄ emission from lakes in China to the global carbon cycle.

Hydrogen-oxygen isotope and nutrients including nitrogen and phosphorus in the sediments and overlying water were monitored in the bay of the XiangXi River (XXB), the first tributary of the Three Gorges Reservoir(TGR), during the impoundment period. The measured data were used to analyze the distribution characteristics of hydrogen-oxygen isotopes and the nutrients during the impoundment period. A binary mixed linear model was utilized to determine the contribution ratio of the main stream of the Yangtze River (CJ River) to GuFuYuanTou (GFYT), the upstream of the river. The study results showed that the sediments simutaneously functioned as source releasing NH₄⁺-N (ammonia nitrogen), DTP (total dissolved phosphorus), and PO₄^3--P (phosphates), and as absorbent collecting NO₃^--N (nitrate nitrogen) during the entire impoundment period. The computed results of the contribution ratios indicated that most nitrogen in the sediment (especially for DTN (total dissolved nitrogen) and NO₃^--N) came from the main stream before the impoundment. After the impoundment, the contribution rate of GFYT increased significantly, with sampling points No. 3 and 4 as the most obvious. Among all the nutrients, most DTP were from GFYT before and after the impoundment and the main stream was the main source of PO₄^3--P before the impoundment. Therefore, while the water in the bay of the reservoir was largely dominated by the influx of the main stream during the impoundment period, the impact of GFYT is more significant than that of the main stream on the sediment-overlying water system.

In this research, the Xiangjiang River areas from the Shifeng bridge to the Majiahe bridge were selected as study areas to assess the ecological risk and release amount of heavy metals in the surface sediments of the Xiangjiang River, Hunan Province, China. A sum of five surface sediment samples were collected, then the total contents and the specific chemical forms of Cu、Pb、Zn、Cd、Cr、Mn、As and Hg in these samples were measured by the inductively coupled plasma mass spectrometry (ICP-MS) and atom absorption spectrophotometer (AAS). Results showed that the average contents of Cd and As in sediments were higher than the standard of class Ⅲ of National Soil Environmental Quality Standard (GB15618-1995). Moreover, the Hakanson ecological risk index was adopted to assess the potential ecological risk of heavy metals in the surface sediments. The results showed that the comprehensive indexes of potential ecological risks (RI) for four sediment samples were higher then 600, suggesting that the Xiangjiang River has been suffered high ecological hazards. Finally, continuous experiments were carried out to study the effect of flow rate and initial pH values on the heavy metals release from sediments. The results showed that the increased flow rate and the decreased initial pH could promote the release of heavy metals in sediments, while the release amount of four heavy metals were too small and the largest release amount of Mn was 7.50μg/(g·d). It suggested that the release of heavy metals in the sediments into the water environment was a slow and long-term process.

Rapid urbanization development has caused high accumulation of heavy metals (Cd, Hg, Cu, Pb, and Zn) in urban lake surface sediments from city parks in Shanghai. Compared to their soil background values, the maximum levels of five metals in lake sediments were higher 3.8~5.8times. The pollution hotspots existed in the urban areas with larger population density and traffic volume, old industrial areas in the west side of Huangpu River, and emerging industrial areas in the suburb. Land use regression (LUR) models were successfully developed to evaluate spatial variations of heavy metal accumulations in urban lake sediments based on four predictor variables such as land use types, traffic variables, population density, and industrial sources. LUR models deduced that the major control factors for Cd and Pb levels in lake sediments were roadway density and commercial land area, respectively, commercial land area and number of industrial point sources for Hg and Cu, residential land area and number of industrial point sources for Zn.

Spartina alterniflora, an invasive alien species, spreads rapidly in the coastal zones of China. It has become the most important invasive plant in coastal wetlands of China and has significant impacts on ecological structure and function of the key zone to the earth. CH₄ is an important greenhouse gas and second only to CO₂. In order to investigate effects of Spartina alterniflora invasion on CH₄ emission and reveal the potential underlying mechanisms of these effects in coastal wetlands of China, each transect was set up in the high and low marshes of wetlands in the Yangtze River estuary, respectively. A pair-wise experimental design between S. alterniflora (invasive plant) and Phragmites australis (native plant) stands in the high marsh, and S. alterniflora and Scirpus mariqueter (native plant) stands in the low marsh, was used at each site of the two transects to minimize the potential effects of background heterogeneities. Compared with native plant stands, S. alterniflora invasion significantly increased plant biomass. Invasion-increase in plant biomass was significantly higher in the high marsh than that in the low marsh, which is beneficial to carbon accumulation in the early succession of coastal ecosystem. S. alterniflora invasion also significantly increased soil moisture, soil organic carbon content, soil nitrogen content, soil microbial biomass carbon and nitrogen contents of coastal wetlands of China. CH₄ emission rates were significantly higher under S. alterniflora than P. australis stands in the high marsh, with mean values of (0.68 ±0.08) mg/(m²·h) and (0.21 ±0.01) mg/(m²·h), respectively. In the low marsh, mean CH₄ emission rate under S. alterniflora stands was (8.31 ±0.50) mg/(m²·h) during the study period, which was significantly higher than that under S. mariqueter stands ((8.31 ±0.50) mg/(m²·h)). The difference in mean CH₄ emission between S. alterniflora and P. australis stands in the high marsh ((0.47 ±0.08) mg/(m²·h)) was significantly lower than that between S. alterniflora and S. mariqueter stands in the low marsh ((4.37 ±0.48) mg/(m²·h)). Our results indicated that the S. alterniflora invasion significantly enhanced CH₄emissions from coastal wetlands of China, probably mainly through improving the quality and quantity of substrates required for CH₄ production, increasing soil microbial biomass and moisture. The invasion-related CH₄ emissions were highly spatially variable; this variability may have been driven by the soil's anaerobic environments, induced by hydrological dynamics. These results can be applied to more reliably estimate and predict invasion-induced changes in CH₄ emissions from wetlands in the context of global climate change. These results also can provide theoretical basis and scientific support for scientific management and rational utilization of coastal zone resources as well as coping with global climate change.

Pesticide pollution in Sihe watershed, China can have a negatively effect on Nansihu lake and aquatic environment of South-North Water Diversion Project. To understand the process of herbicides transport and best management practices in the watershed, transport simulation of herbicide including atrazine and its transformed products in Sihe watershed performed by SWAT model and field investigation. The results demonstrated that there was a high correlation between the output of herbicides and runoff. The time of herbicides output was mainly concentrated in July and August, which accounted for more than 69% of output in the whole year. The spatial distribution of herbicides load in the watershed was affected by the length of the river and distribution of agricultural land. The output of atrazine distributed primarily in eastern and central region of upstream areas, and catchment outlet of herbicide output was in the middle. However, the spatial distribution of the output of atrazine transformed products including DEA and DIA were similar to their parent compound, which mainly located in the catchment outlet of the downstream areas and the central region in Sihe watershed. The study can provide theoretical support for the management of herbicide migration in the basin.

Gaseous carbon dioxide can provide an essential carbon source during microalgal photosynthesis. Mixing, dissolution and transportation characteristics of carbon dioxide have significant impacts on the growth of microalgae. In a photobioreactor, the behaviors of carbon dioxide bubbles during growth, detachment, coalescence and rising are significantly affected by the gas distributor. In this study, the effects of orifice diameter and spacing of the gas distributor on 15% CO₂ bubble behaviors, dissolution and mixing characteristics of carbon dioxide as well as performances of microalgal growth and carbon dioxide fixation have been investigated. The rising velocity of bubble was reduced with decreasing orifice diameter and spacing, thereby increasing the retention time of carbon dioxide in microalgal suspension. As the parameters of gas distributor were optimized, the gas-liquid mass transfer coefficient was improved by 143%, the mixing time was reduced by 24%, the concentration of microalgae was increased by 18.8%, and the carbon dioxide fixation rate was enhanced by 23.2%.

Understanding the fate and transport of pathogenic microorganisms in porous media is of great significance to protect water resources. On the basis of the previous research at home and abroad, the migration behaviour of microorganisms in porous media has been summarized. Several studies have shown that, pathogenic microorganisms as a kind of biocolloid, its transport will be controlled by a series of complex mechanism. In addition to the common hydrodynamic and hydrochemical conditions, microorganisms are also affected by itself characteristics, medium particles and environmental factors during the migration process. On this basis, the migration behaviours of microorganisms in saturated porous media and unsaturated porous media have been discussed, and the research focus in recent years have also been briefly summarized. At present, a great number of related researches about this topic have been published. However, due to the complexity of underground environment and the variability of microorganisms, it is necessary to further discuss the remediation of microorganism pollution in groundwater system.

This paper used the contaminant fate and transport multimedia model (EPACMTP model) to assess the risk classification method for a national soil quality survey program. Regional sensitivity analysis, global sensitivity analysis and empirical verification were conducted. The work focused on the completeness of indicators, credibility of classification and robustness of weighting and scoring. The result showed that almost all (13in total) sensitive parameters were covered by the risk classification method, except for leachate concentration. Parameters with high sensitivity and importance were usually given relatively high weights. The scores for site area and distance to receptor were shown to be reasonable. The classification for low-risk sites were generally accurate. This study recommended that more attention should be paid to contaminant transport process. Suggestions were given on indicator weighting and scoring. We also suggested focusing on medium-and high-risk sites, as well as arsenic contaminated sites.

While making economic benefits, taking into account sustainable development has become a necessity for promoting the new normal development of the industry. This paper firstly adopted the multi-regional input-output model of Ghosh, and calculated the total carbon emission coefficient and the induction coefficient of the income side of various industries in China in 2009 from the aspect of industry. Then, according to the size of the two coefficients, 34industrial sectors are divided into four categories. The empirical results showed that the first category of industries has better economic driving capacity and has a negative impact on the environment. Class Ⅱ industries need to be promoted integration within the industry to improve energy efficiency. Class Ⅲ industries are welfare industries and should be protected and supported. Class IV industries with a high coefficient of induction and a low full-return-side carbon emission coefficient, both industry-friendly and economical benefit, satisfy the inherent requirements of the current supply-side of internal need of structural reform and need encouragement and development.