The industrial source is one of the major contributors to volatile organic compounds (VOCs) emission, which are the crucial precursors to ozone (O₃) and aerosols. Due to several VOC emission control policies enacted in recent years, the industrial VOC emission structure in the Pearl River Delta region (PRD) might have changed greatly. In this study, a long-term industrial VOC emission inventory in the PRD region during 2010~2017 was developed. Based on a time-dependent speciated profile database, the industrial VOC emission inventory was disaggregated into species by sub-sector. The change of industrial VOC emission structure and its cause were also discussed. VOC emissions from industrial sources in the PRD region increased from 380kt in 2010 to 410kt in 2013 but then decreased to 320kt in 2017 due to the implementation of VOCs emission control measures, such as promoting the use of water-based coatings and the installment of exhaust treatment facilities. As a result, emission contributions of metal surface coating industry, furniture manufacturing industry and rubber and plastic products industry, which were dominated by aromatic hydrocarbons, also declined to some extent. The aromatic species of industrial VOCs emission decreased significantly, partly led to the increase of proportions of alkanes and VOCs. These results were informative to develop robust control measures to further control VOC emission in the PRD region.

The mass distribution characteristics of PM_2.5 particles during different combustion phases of residential coal were studied in this work. PM_2.5 particles during the flaming phase of burning bituminous coal in an over-fire stove were mainly particulate matters (PM) with diameter below 0.2μm (d₅₀=0.15μm) and peaked at 0.2~0.5μm (d₅₀=0.38μm) during the fuel-adding and smoldering phases. Their mass ratio was between 46.6% and 68.97%. On the other hand, PM emitted from the whole process of burning briquettes in an under-fire stove were mainly below 0.2μm, and the mass ratio was 44.64%~56.24%. The scanning electron microscopy (SEM) observation showed that the PM_2.5 particles emitted from coal-burning were cluster-like structure formed by the aggregation of a large number of ultrafine particles. Also, the emission factor (EF) of PM_2.5 calculated by the carbon balance approach of the bituminous and over-fire stove in the fuel-adding phase was 4.72g/kg, which was 12 and 11 times of that in the flaming and smoldering phases respectively. The replacement of bituminous to briquette will result in the reduction of PM_2.5 EFs by 90.9% during the fuel-adding phase, leading to a significant decrease in PM_2.5 emission.

Both HYSPLIT backward trajectory model and Global Data Assimilation System (GDAS) meteorological data from the National Centers for Environmental Prediction (NCEP) were used to analyze the 48h backward trajectories of hourly airflow in the eastern Pamirs from March, 2019 to February, 2020. The clustering analysis was used to classify the airflow backward trajectories in different seasons. The annual mean values of surface PM₁₀ and PM_2.5 concentrations were (29.4±16.4) and (9.3±5.1) μg/m³, respectively, indicating that PM₁₀ was the main particulate matters over the eastern Pamirs. Therefore, the hourly observation data of PM₁₀ concentrations were also used to analyze the spatial characteristics of different transport pathways and its contribution to the surface PM₁₀ concentrations in the eastern Pamirs. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) were applied to identify the potential source regions and contribution of PM₁₀ in different seasons to the eastern Pamirs during the study period. Seasonal variations of PM₁₀ transport pathways in the eastern Pamirs were obvious. The westerly airflows from Central Asia carried high concentrations of PM₁₀ in spring, while the airflows from west Xinjiang brought high concentrations of PM₁₀ in summer, and the both airflows made the equal concentration of PM₁₀ in autumn, while the airflows from South Asia took along higher concentrations of PM₁₀ in winter. Furthermore, the potential source regions of PM₁₀ were mainly located in west Xinjiang, northeast Afghanistan, northeast Pakistan, central and east Tajikistan in spring, in Kashgar and north Hotan in west Xinjiang in summer, in east Turkmenistan, southeast Uzbekistan, north Pakistan, and north Afghanistan bordering south Tajikistan areas in autumn, and in northeast Pakistan, north India and north Afghanistan in winter.

Based on the OMI/Aura satellite data from 2007 to 2016, the temporal and spatial distribution characteristics of ozone (O₃) concentrations (0~3km), sulfate aerosol optical depth (SAOD) (0~2km) and sulfur dioxide (SO₂) (within the boundary layer) column concentrations in Beijing were analyzed. The results showed an upward trend in the past 10years with the minimum ozone concentration in 2007 (33.65μg/m³). The values of SAOD decreased from 2007 to 2011 and increased from 2011 to 2016, with a maximum and minimum annual average in 2017 (0.357) and 2011 (0.252), respectively. The concentrations of SO₂ decreased from 2007 to 2016 and decreased after 2011. The lowest annual average concentration of SO₂ was in 2016, which was 60.42% lower than the highest annual average concentration in 2007. The concentrations of O₃ was highest in summer, followed by spring and autumn, and lowest in winter. The seasonal characteristics of SAOD were the same as O₃. SO₂ occurred most frequently in winter, resulting in the more severe pollution in heating period than in non-heating period.

The concentrations of heavy metals (As, Cr, Cd, Pb and Cu) were investigated in dust of northern suburb of Xuzhou, China, during the third to fourth season, to analyze the contamination level, ecological risk and health risk due to the atmospheric deposition. The deposition flux of Pb (1.49mg/(m²·month)) was the highest and that of Cd (9.23μg/(m²·month)) was the lowest, The concentrations of five heavy metals were all higher than the local soil background values, but lower than the values regulated by corresponding Chinese National Standard. The deposition fluxes of Cu (1.21mg/(m²·month)) and Cr (0.96mg/(m²·month)) in atmospheric deposition were slightly higher than those of other industrial cities, while Cd (9.23μg/(m²·month)) was relatively lower. Cu indicated the strongest spatial variation, which was 110.05%. The geo-accumulated index of five heavy metals followed the order:Cu > Pb > Cd > As > Cr in the third season, while Pb > Cu > Cd > As > Cr in the fourth season. Cu, Cd and Pb were between moderate and very high pollution level, As was between slight and moderate level, and Cr was classified as slightly uncontaminated. Generally, all of heavy metals at 10 sampling sites had minor ecological hazard, and especially As in dust had both non-carcinogenic risk through hand-mouth intake and carcinogenic risk to children.

Monolithic honeycomb molecular sieve carriers were used to prepare copper, manganese and cerium supported catalysts. The catalytic performance and stability of the catalyst were investigated by microwave-assisted catalytic combustion of VOCs (toluene, acetone, ethyl acetate). And affecting factors of catalytic activity were analyzed and temperature distribution of the bed was tested simultaneously. The removal efficiency of VOCs with an initial concentration of 200~2000mg/m³ was between 80% and 92% under conditions of microwave power 1.3kW, catalyst bed volume 300'm×300mm×300mm, reaction temperature of the fixed bed higher than 300℃, and air volume 5m³/h. Temperature was a prerequisite for the oxidative degradation of VOCs, and the effect of temperature rising on the degradation of VOCs was no longer obvious after the bed temperature exceeded 300℃. Monometallic oxides of copper, manganese and cerium and their composite oxides were main active components with spinel structure. VOCs were oxidized on the surface of the active components that followed by pseudo-first order reaction. Cu-Mn-Ce/Molecular sieve honeycomb catalyst had both high catalytic activity and good stability after six-time repetitive tests although high temperature made some changes for the structure.

Aldehydes and ketones compounds before and after electrostatic fume purifiers were sampled using 2,4-dinitrophenylhydrazine (DNPH) silica tube at nine restaurants, and then high performance liquid chromatography (HPLC) was used for quantitative measurement. Total concentrations of aldehydes and ketones compounds in the exhaust from nine restaurants ranged from 419.5 to 3372μg/m³ before the purifiers, while they varied from 415.8 to 2934μg/m³ after the purifiers. the concentrations of reference volume condition corresponded to 783.4~3761 and 541.7~2997μg/m³, respectively. It suggested that their concentrations were related to different cooking processes, the number of working stoves and the exhaust air volume. The concentration of C1~C3compounds accounted for more than 66% of the total detected carbonyl groups. formaldehyde was the highest detected compound, followed by acetaldehyde. The content of C4~C8compounds was relatively low. The average purification efficiency of electrostatic fume purifier on aldehydes and ketones compounds was 31.82%, with the highest efficiency reached to 69.14%. Formaldehyde has the highest purification efficiency with an average of 35.21% and a maximum of 80.10%. The composite electrostatic fume purifier can achieve a better purification effect than the normal electrostatic fume purifier.

A series of Ag-AgIO₃/BiOI photocatalysts were successfully synthesized by a coprecipitation-photoreduction method and characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and electron spin resonance (ESR). The effects of AgIO₃ content, fluorescent lamp (FSL) irradiation, solution temperature, pH value, SO₂ and NO on Hg⁰ removal were investigated in a photocatalytic reactor. In comparison to BiOI, Ag-AgIO₃ photocatalyst exhibited an enhanced fluorescent-light-driven photocatalytic activity for Hg⁰ removal. When the loading of AgIO₃ was 4wt.%, the removal efficiency of the Ag-AgIO₃/BiOI photocatalyst was as high as 98%. Compared with NO, the inhibitory effect of SO₂ on Hg⁰ removal efficiency became predominant. Due to the high dispersibility of Ag and AgIO₃ on the surface of BiOI, the visible light absorption performance of Ag-AgIO₃(4%)BiOI was significantly improved. The combination of fluorescent lamp irradiation and Ag-AgIO₃/BiOI photocatalyst could produce a large number of active species. The mechanism showed that in the efficient mercury removal system of the Ag-AgIO₃/BiOI photocatalyst, the superoxide radical (·O₂^-) was the most important active material, and the holes (h⁺) and hydroxyl radical (·OH) were the secondary factors.

Two-stage partial nitrification and anammox process was used to treat magnetic coagulation domestic sewage. Through regulating aeration and bioaugmentation, partial nitritation of magnetic coagulation sewage was achieved, and advanced nitrogen removal was proceeded by coupling anammox reaction. The 100days' operational results showed that controlling intermittent aeration and bioaugmentation, nitrite accumulation rate reached 89.93%. Further increasing in DO from 0.6~0.8 to 1.0~1.2mg/L was beneficial to enhance ammonia and TN removal efficiencies. The system removed up to 95.45% of ammonia nitrogen and 86.28% of total nitrogen, and achieved stable and efficient nitrogen removal. During the treatment of magnetic coagulation pretreated sewage in the partial-nitritation reactor, the residual dissolved organic matter was used to provide carbon source for denitrification under intermittent aeration. COD removal efficiencies of the combined process achieved 64.65%~74.42%. The organic components in the effluent of partial- nitritation reactor and the final effluent of the system were similar, mainly refractory organics.

The impact of Ni²⁺ on the aerobic granular sludge (AGS) system was explored by inoculating the return sludge from A²/O process of a municipal wastewater treatment plant in sequencing batch reactor (SBR). The mature AGS cultured at 25℃ for about 50 days had a morphology of sphere or ellipsoid with a small number of filamentous bacteria on the surface, and a particle size of 2~4mm. The AGS system keeps a mixed liquid suspended solids (MLSS) of 6000mg/L and sludge volume index (SVI) at 40~50mL/g. Ni²⁺ in the concentration range of 0~2mg/L will improve the stability of AGS, increase MLSS, and decrease SVI. Meanwhile, the extracellular polymeric substances (EPS) in AGS increased with the addition of Ni²⁺and contained significantly more protein (PN) than polysaccharide (PS). The inhibition of Ni²⁺ on removal of total nitrogen (TN) by AGS was greater than that of chemical oxygen demand (COD). Finally, the removal rate of COD and TN could be maintained above 95% and 70%, respectively.

In order to explore the impacts of extracellular metal elements on anammox granular sludge, anammox granular sludge was divided into three groups based on its sizes (0.5~1.4mm,1.4~2.8mm and>2.8mm). Then, the extracellular polymeric substrances (EPS) of the anxmmox granular sludge were extracted. Results show that proteins (PN) accounted for more than 84.2% of the EPS content, showing that PN were the main components of EPS. The anammox granular sludge EPS mainly contained four metal elements, K, Na, Ca, and Mg. In addition, above four metals were arranged in a descending order based on their concentration. With the increase in particle size, more metals and PN were found in EPS. The ionic forms of K, Ca, and Mg in the EPS accounted for 68.6%, 56.2%, and 94.7%, respectively. When the EPS were treated with cation exchange resin, the Zeta potential of the EPS of the 0.5~1.4mm, 1.4~2.8mm, >2.8mm groups decreased by 4.7mV, 7.2mV, and 9.1mV, respectively. Furthermore, the metal ions in EPS could promote the aggregation of granular sludge by compressing the electric double layer, and the effect of metal ions was more significant on larger-size granular sludge in Zeta potential.

In order to explore the competition relationship between activated sludge and biofilm in hybrid MBBRnitrification system, the influence of conventional factors (sludge concentration, DO, temperature, C/N) on the nitrification effect of hybrid MBBR system was studied through lab-scale experiment. The changing trend of sludge volume load and MBBR (moving bed biofilm reactor) biofilm volume load in the system was analyzed, and the competition relationship of sludge membrane was obtained. The sludge concentration, DO and temperature were positively related to the volume load of hybrid MBBR nitrification system in a certain range. In addition, compared with MBBR biofilm, the activated sludge in the system has an obvious advantage in competing for DO and substrate, while MBBR biofilm had a stronger ability of low temperature resistance. The influent C/N was negatively correlated with the nitrification load of hybrid MBBR system, and the activated sludge had more advantages than MBBR biofilm in response to the high influent C/N, and MBBR "inlay" enhanced the SND effect of the system. The results of microbial analysis showed that Nitrospira was the dominant nitrifying bacteria in hybrid MBBR system, and the enrichment capacity of suspension carrier biofilm was significantly higher than that of activated sludge.

In order to develop a quick start-up method for the anaerobic ammonia oxidation (Anammox) and Hydroxyapatite (HAP) (Anammox-HAP) granular sludge system, an Anammox attached film expanded bed reactor (AAFEB) was used, inoculated a small amount of Anammox sludge. The variation of sludge particle size and extracellular polymers (EPS) in the system were investigated by regulating influent substrate concentration and hydraulic residence time (HRT). Meanwhile, the nitrogen and phosphorus removal performance of the system was analyzed. Under the conditions of low up-flow rate of 0.213~1.066m/h and Ca/P=5.5molar ratio, the Anammox granular sludge system was started up successfully, with increasing influent nitrogen load. The removal efficiencies of total nitrogen and orthophosphate were (78.01±9.84)% and (63.83±9.89)%, respectively, and the total nitrogen volumetric loading reached 2.74kg/(m³·d). The average particle size of micro-granular sludge was 0.4mm in 150days. The morphology and element distribution of the sludge granules showed that they were Anammox-HAP granules. With the increase of granular sludge particle size, the proportion of PS in EPS was basically unchanged, while the proportion of PN increased from 54.43mg/g to 137.40mg/g, and PN/PS increased from 6.63to 7.71. There was a positive correlation between PN proportion in EPS and sludge particle size. It was PN that played a major role during sludge granulation.

The influences of vitamin B₁₂ (VB₁₂), a biocatalyst, on the reductive degradation of 8:2fluorotelomer alcohol (8:2FTOH) in anaerobic activated sludge were investigated. VB₁₂ could change the dynamic characteristic of reductive degradation of 8:2FTOH by anaerobic activated sludge and enhance the final removal rates of 8:2FTOH, but there were the upper and the lower dosage limits for the VB₁₂. The final removal rates of 8:2FTOH in anaerobic activated sludge could not be enhanced while the spiked dosage of VB₁₂ was less than or equal to 1mg/L, but no further improvement was also observed when the VB₁₂ concentration was increased to more than or equal to 5mg/L. The final defluorination rates of 8:2FTOH could be significantly inhenced with spiking all VB₁₂ dosages in the present study. The influences of VB₁₂ dosages on the removal rates and defluorination rates of 8:2FTOH in the anaerobic activated sludge were inconsistent. In addition, when the anaerobic activated sludge was amended with the higher concentrations of VB₁₂, the accumulation of intermediate degradation products (i.e. polyfluorinated compounds) was generally inhibited and the lower total molar recoveries of 8:2FTOH were observed while the molar yields of final degradation products (i.e. perfluorocarboxylates), as well as the mineralization defluorination rates of 8:2FTOH, were enhanced.

Magnetic ordered mesoporous carbon (Fe-OMC) was successfully synthesized via hydrothermal route and applied as adsorbent for the removal of bisphenol A (BPA) in water. Through the characterizations of high resolution transmission electron microscopy, X-ray diffraction, specific surface area analyzer and vibrating sample magnetometer, the adsorbent possessed large specific surface area, unique ordered mesoporous pore structure, rich oxygen-containing functional groups and high super paramagnetism. During the application, Fe-OMC could effectively adsorb and remove BPA from water and the equilibrium adsorption capacity reached 72.62mg/g, and still maintained favorable adsorption ability after separation and recovery. With increasing BPA concentration from 1mg/L to 20mg/L, the equilibrium adsorption capacity increased from 8.33mg/g to 91.78mg/g. As solution pH raised, it presented a trend of first decreasing, then increasing and finally decreasing and the highest adsorption occurred at pH 8 (75.34mg/g). The adsorption process could be well described by pseudo-second-order adsorption kinetic model and Langmuir adsorption isotherm model. The calculated thermodynamic parameters illustrated that the BPA adsorption onto Fe-OMC was a spontaneous and exothermic process.

The reductive degradation of technical perfluorooctanesulfonate (PFOS) were investigated in a biomimetic system consisting of vitamin B₁₂(VB₁₂) as catalyst and nanoscale zero-valent iron (nFe⁰) as reductants. Both branched and linear PFOS could be degraded simultaneously, and the biomimetic degradation of linear PFOS was first reported. The degradation was well described by a pseudo-first-order kinetic model, and increasing the incubation temperature was favorable for the removal of PFOS and for its defluorination. Three types of PFOS degradation products, including 4 perfluoroalkylsulfonates (perfluorocarbon chain length:C4~C7), 9perfluorocarboxylates (perfluorocarbon chain length:C2~C7, C10, C11, and C13), and 5 polyfluorinated acids (i.e. H-perfluorohexanoate, H-perfluoroheptanoate, H-perfluorooctanoate, H₂-perfluorooctanoate, and H-perfluorooctanesulfonate) have been qualitatively determined by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF). For the first time, Perfluoroalkylsulfonates and perfluorocarboxylates were detected among the biomimetic reduction products of PFOS catalyzed by VB₁₂, while some long-chain perfluorocarboxylates, including perfluoroundecanoate (C10), perfluorodocecanoate (C11) and perfluorotetradecanoate (C13), were first reported as the degradation products during decomposition of PFOS. It was unclear whether H-perfluoroalkanes (carbon chain length:C2~C7, C10, C11, and C13) were the biomimetic degradation products of PFOS, and further investigation is warranted.

Thermal activation of persulfate (PS) is an effective method for degradation of organic pollutants, but the high temperature has become restrictive factor. The effects of active carbon (AC) on the thermal activation of persulfate (PS) and the subsequent degradation of p-nitrophenol (PNP) in water was systematically investigated. The effects of critical parameters, including the initial pH, PS concentration and dose of AC were also investigated. AC could significant enhanced thermal activation of PS for high efficient degradation of PNP. The degradation efficiency of PNP reached 100.00% in AC/PS system, whereas only 31.69% in PS system with AC, PS, and PNP concentration of 1.0g/L, 2.0mmol/L, and 10.0mg/L, respectively, initial pH of 3.5, temperature of 50℃ and reaction time of 120min. Free radical quenching experiments demonstrated that the AC/PS/PNP system was radical reaction, and SO₄·^- and ·OH were involved in the AC/PS/PNP system, and the SO₄·^- were the main radical for the PNP degradation. The mechanism analysis revealed that the defective sites on AC were involved for weakening the O-O bond in PS and subsequently cleaving O-O bond by heat to generate sulfate radical. The analysis of degradation intermediates suggested that AC could only accelerate the degradation efficiency of PNP but not alter the reaction pathway in PS systems.

Co₃O₄-biochar composite (Co-OB) was prepared by hydrothermal impregnation, and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and attenuated total reflection-infrared spectroscopy (ATR-IR). Degradation efficiency of atrazine (ATZ) was evaluated by Co-OB activated peroxymonosulfate (PMS). The effects of PMS concentration, humic acid (HA) and Cl^- on ATZ degradation were investigated. When 20μmol/L ATZ was treated by 0.025g/L Co-OB and 200μmol/L PMS in room temperature, a removal rate of ATZ at 86.3% was achieved within 10min. The efficiency of Co-OB/PMS oxidation of ATZ was 2.2times higher than the sum of that in biochar (OB) and Co₃O₄ activation. The ATZ removal rate was significantly increased with increasing PMS concentration. Presence of Cl^- and HA played negative effects on the degradation of ATZ, and the inhibitory effect was more obvious as the concentration of Cl^- and HA increased. The radical scavenging experiments showed that ·OH and SO₄·^- played a dominant role in ATZ degradation. Six transformation intermediates were documented by liquid chromatography-mass spectrometry (LC-MS), and a degradation pathway of ATZ during Co-OB/PMS oxidation was presumed. The stability experiments showed that Co-OB was reusable corresponding with low Co²⁺ dissolution.

This study investigated the degradation of quinoline in the sulfate radical (SO₄^-·)-based advanced oxidation system introducing by Fe²⁺-activated persulfate (K₂S₂O₈, PS). The Fe²⁺/PS system effectively degraded quinoline compared with the sole PS and Fe²⁺ system. Optimal operation parameters were comprehensively evaluated, specifically, when the initial quinoline concentration was 250mg/L, the optimal quinoline/PS molar ratio, Fe²⁺/PS molar ratio, initial pH, reaction temperature and time were 1:10, 3:1, 3, 45℃ and 80min, respectively, the quinoline degradation rate reached to 100%. Increasing the concentrations of PS and Fe²⁺effectively improved the degradation rate of quinoline, but the effect on quinoline removal was not significant till exceeding a certain limit. The degradation rate increased with the increase of reaction temperature, meanwhile, the acidic condition more suitable for its removal. Moreover, the degradation reaction kinetics, introduced by Fe²⁺/PS oxidation, fit the first-order reaction. Free radical quenching experiments confirmed the existence of SO₄^-·, OH·and other reactive oxygen radicals in the system, in which OH·was dominant in the degradation of quinoline. Two intermediates, 8-hydroxyquinoline and 2(1H)-quinolinone, were detected by GC/MS, from which two pathways for quinoline degradation were inferred. Results of E.coli acute toxicity showed that although more toxic intermediate products may be produced during the removal of quinoline by Fe²⁺/PS system, the acidic conditions and higher reaction temperature accelerated the detoxification of the treatment system.

We studied a MnCo layered double hydroxides (LDH) catalyst and loaded it on reduced graphene oxide (rGO) to prepare MnCo-LDH/rGO electrode and investigate its oxygen reduction properties. The MnCo-LDH and MnCo-LDH/rGO exhibited the best outstanding morphology and catalytic performance at the Mn/Co ratio of 1:3. Compared with MnCo-LDH, the MnCo-LDH/rGO illustrated a prominent oxidation-reduction potential (-0.425V) and peak current (0.749mA/cm²). Furthermore, the MnCo-LDH/rGO afforded a Rhodamine dye B(RhB) degradation rate of 98.6% in 120min with a current density of 30mA/cm², while the initial concentration of RhB was 20mg/L, which exhibited superior degradation performance. The results of Rotating Disk Electrode (RDE) and free radical quenching experiment showed that the number of electrons transferred in the reaction was 2 and the main radical was·OH. In brief, the MnCo-LDH/rGO with low cost, facile synthesis and high catalytic activities for ORR has good potential and application prospect in electrochemical catalysis.

Based on the main characteristics of open channel flows, this research built a random walk model for fine particles within the inhomogeneous open channel turbulence, with modifications concerning influences of the vertical inhomogeneity of turbulence intensity and loitering effect. Using the established model, the sedimentation loss of fine particles in the open channels was simulated. Simulation results showed that, when influence of the loitering effect was not considered, particle sedimentation loss rate could be calculated by the ratio of particle settling velocity to the water depth; when influence of the loitering effect was considered, particle sedimentation loss rate would have a 18%~27% reduction compared to quiescent environments. The reduction percentage was basically consistent with the asymptotic value of declining percentage of particle settling velocity (19%~25%) in the homogeneous turbulent fields. The conclusion of this article was mainly based on two premises that the resuspension of particle was not considered, and the loitering effect was the dominant mechanism of turbulence on particle settling. Proposed method and results can be applied to calculate the sedimentation process of particles to the channel bottom more accurately.

Based on the estimation of car ownership in China from 2018 to 2050 with Gompertz model, this research identified the average lifespan of cars in China as 9a by a time-series material flow analysis model. This result was used to estimate the amount of end-of-life vehicles (ELVs) in China to reach 25.35 million by 2025 with extreme uneven geographical distribution. The recycling potential of platinum group metals was calculated accordingly, and compared with various scenarios of demand. The results show that:according to current catalyst consumption level, the demand for platinum group metals in China peaked in 2019, where Pt, Pd and Rh reached 4.57, 65.70 and 7.92t. It is expected to achieve closed-loop supply in automobile industry. If the EU emission standards are applied in China, the demand for platinum group metals will increase significantly, which could lead to serious shortage of supply. The demand for Pt, Pd and Rh will reach 85.01, 109.38, 8.37t in 2020. In conclusion, we suggested to incorporate the recycling of waste catalysts in the extended producer responsibility system for cars.

The effects of sewage sludge (SS), food waste (FW), corn cob (CC) and bagasse (BG) biochar on the anaerobic biological treatment of food waste were investigated. Meanwhile, the key enzyme activity, microbial community distribution and metabolic pathway of anaerobic sludge were analyzed. The average COD removal rate increased by 29.49%, 23.16%, 29.42%, and 40.32% after addition of the four kinds of biochar in the anaerobic reactor, respectively. The activity of acetokinase in the four anaerobic reactors was 0.40, 0.42, 0.96 and 0.98μmol/g, respectively. The high acetokinase activity of the anaerobic sludge in the CC and BG groups demonstrated that the addition of the CC and BG biochar promoted the hydrolysis and acidification of food waste. In addition, the ratio of protein/polysaccharide of extracellular polymeric substances in the anaerobic sludge was 0.415, 0.56, 1.89 and 2.8, respectively. It was demonstrated that adding CC and BG biochar improved the stability of anaerobic sludge. In the four anaerobic reactors, Bacteroidetes, Proteobacteria and Firmicutes were the dominant phylum, and the addition of BG biochar promoted the growth of Proteobacteria and Firmicutes. As for the archaea, Methanobacterium and Methanothrix were the dominant species. Methanobacterium in the SS group had highest abundance (53.48%), while Methanothrix in the BG group had the highest abundance (42.72%). Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analysis showed that archaea and bacteria were mainly metabolized by carbohydrate and amino acids. In addition, the transport level of microbial membrane was improved in presence of BG and SS biochar.

Batch experiments were conducted to investigate the dissolution of excess sludge organic matter (SCOD) to understand the physical and chemical properties and dissolution characteristics of excess sludge under low temperature heat treatment. The dissolution rate of soluble carbohydrate (SC), soluble protein(SP) and the fluorescence properties of the dissolved organic matter (DOM) were also investigated. With the increase of heat treatment temperature, the cracking degree of SCOD achieved its highest level at 80℃, while the dissolution rate reached its peak value at 90℃ and the SC was the highest at 70℃. Along with the treatment the mass concentration maximized at 90℃, that of the SP was on its top at 60℃, while the content of VFAs was the largest at 60℃. The results of the liquid chromatography with online organic carbon (LC-OCD) analysis demonstrated that the biopolymer fraction got its highest proportion in DOM at 80℃. The results of fluorescence analysis showed that the DOM contained C1organics (Ex/Em, 282/324nm), metabolic proteins C2(310/364nm), visible humic acids C3(278,338,358/424nm), and soil fumarates C4 (270,318,354/476,524nm) after heat treatment of excess sludge. For the sludge handled by hot water decomposition pretreatment, its protein-like organics presented maximum fluorescence intensity at 80℃ while corresponding metabolic protein has its maximum fluorescence intensity at 60℃. According to the above results, the optimzed operational condition for the dissolution of organic matter from sludge could be set as treatment duration of 60minutes under 80℃.

This study measured atmospheric bulk and dry sulfur depositions in 2015 and 2016 in a paddy rice region in the hilly region in central China, analyzed the relationship between SO₄^2- and NO₃^- in rainwater, and explored the sources of atmospheric sulfur compounds. The annual average concentrations of SO₂-S in the atmosphere and SO₄^2--S in the rain water in the study region were 8.5μg/m³ and 1.8mg/L, respectively. The annual average of the total sulfur deposition was 26.8kgS(hm²·a), with the annual average of bulk deposition of 18.2kgS(hm²·a), and the annual average of dry deposition of 8.6kgS(hm²·a). There were significant seasonal variations in the sulfur bulk and dry depositions. The sulfur bulk deposition in spring was the highest, while the sulfur dry deposition in winter was the highest among the seasons. The mass ratio of NO₃^-/SO₄^2- in the rainwater was less than 1in most of the months, indicating that the primary source of the atmospheric sulfur compounds was the stationary pollution source (coal burning) in the study region. There was relatively high sulfur deposition in the paddy rice regions in the hilly region in central China in the studied period, but the sulfur deposition had been decreased largely as compared to those measured in early 2000s. Thus, sulfur fertilizers need to be used in the croplands in this region based on the soil sulfur balance status, so as to keep high yields of crops.

The coking plant site could be divided into the coal stockyard, the coking unit, the chemical product unit according to manufacturing processes. 40 soil samples were collected from different areas in order to analysis levels, distribution, polluted ways and composition of PAHs in soil of the coking plant affected by different sources. The site was severely polluted and BaP was the primary pollutant being relevant to health risks. The chemical product unit (1733.87mg/kg) > the coking unit (32.86mg/kg) > the coal stockyard (21.21mg/kg) based on median values of ΣPAHs concentration, leakage or landfill of chemical products, dry/wet deposition from exhaust, leaching of coal-like materials were the main corresponding causes for the different PAHs levels of the three units. It is hard to distinguish source characteristic of PAHs distinctly in soil of different units by just using isomeric ratios. According to the ratio of low molecular weight PAHs between high molecular weight PAHs, the chemical product unit (deep soil, 7.39)>the chemical product unit (surface soil, 1.33)>the coal stockyard (1.06)>the coking unit (0.39). Composition of PAHs in soils mainly depended on characteristic of pollutants from different sources and degradation from external environment together. 4, 5ring PAHs were the primary pollutants of the soils, PAHs in the coal stockyard and the chemical product unit were dominated by Nap and Phe, whereas BbF, Fla, Chry accounted for larger proportion in the coking unit.

The concentrations of 16 priority PAHs in soil of 28 typical substation in the south of Hebei province were detected and analyzed. The total concentrations of PAHs in soil of substation ranged from 223.48 to 1681.17μg/kg, with a mean of 443.94μg/kg. The substation was at a slight pollution level for PAHs. The pollution sources and contribution rates have been analyzed using ratio method and Positive Matrix Factorization (PMF). PAHs was mainly sourced from the oil and its derivatives. The biomass and fossil fuels combustion source contribution rate was 42.1%, and the oil and its derivatives combustion source contribution rate was 57.9%. The results of health risk assessment showed that the carcinogenic risk of PAHs in the substation soil was higher than that of non-cancer. The potential carcinogenic risk sites in the substation under test accounted for 11%, and the main exposure ways of carcinogenic risk were calculated to be oral intake and skin contact. In conclusion, the ecological risk of PAHs in the substation site was at a low level.

One highly efficient tribenuron methyl-degrading strain, named SD-1, was isolated. According to the phenotypic, physiological and biochemical characteristics, combined with 16S rRNA gene sequence analysis, the strain SD-1 was identified as Methylopila sp. SD-1, which was the first reported strain in the genus of Methylopila that could degrade tribenuron methyl. The strain SD-1 completely degraded 50mg/L of tribenuron methyl in 4d. The optimum temperature and pH were 30℃ and 7.0, respectively. The toxicity of the intermediate from the degradation of tribenuron methyl to soybean growth was significantly reduced. Soybean root exudates proved to promote the growth of strain SD-1, the number of strain SD-1increased from 1.0×10⁷CFU/mL to 6.7×10⁷CFU/mL after 5d. Root exudates contained 16 kinds of amino acids, and the strain SD-1 showed chemotaxis response towards Asp, Glu and Phe in root exudates. The suspension of strain SD-1 was inoculated and the soybean was planted in the soil polluted by tribenuron methyl (3mg/kg). After 4days, strain SD-1 colonized on the root of soybean depending on chemotaxis, and the survival rate of SD-1 was increased. Compared with the treatments that didn't plant soybean, the degradation rates of tribenuron methyl by strain SD-1 in the soybean rhizosphere soil were increased by 36.0%.

In order to repair heavy metal contaminated soil and ensure the quality and safety of vegetables, the urease-producing bacteria were screened from the vegetable rhizosphere soil by urease-producing medium. The adsorption and immobilization of Cd and Pb by functional strains were studied. Effects of functional strains on the growth and absorption of Cd and Pb by different vegetables were also studied by hydroponic experiment. Ten urease-producing bacteria were isolated from the rhizosphere soil of lettuce. Two strains, Microbacterium foliorum CH6 and Bacillus thuringiensis N3, showed highly ability to producte urease (62.6 and 59.6 (mS/(cm·min), respectively) and immobilize Cd and Pb (84.6%~91.3%). SEM-EDS, FITR and X-ray showed that CH6and N3reduced the content of Cd and Pb in the solution through cell wall adsorption and induced precipitation. Soil static test showed that strains CH6 and N3 reduced the exchangeable contents of Cd and Pb (46.3%~66.7%) and increased the carbonate bound and residual fraction contents of Cd and Pb (40%~95.4%) in soil. A hydroponic experiment showed that, strains CH6 and N3 significantly reduced the Cd (39.2%~81.4%) and Pb (27.4%~82.4%) contents in the edible parts of lettuce, Chinese cabbage and Ipomoea aquatic. Urease-producing bacteria CH6 and N3 could mineralize CD and Pb in soil, reduce the content of available heavy metals in soil, and inhibit the absorption of Cd and Pb by lettuce, Shanghai green and cabbage.

In order to study the monitoring method of low-concentration microorganisms in clean environment, three kinds of low concentrated Gram-positive and negative bacteria, were prepared to evaluate the enriched and concentrated efficiency of microorganisms. The experiment showed the bacteria concentrated by the modified magnetic beads had a higher enrichment and concentration ratio compared with E. coli and S. aureus. After non-specific enrichment of microorganisms in tap water, drinking water and bottled water, there were significant difference among these three types of water for the 16S rDNA gene copy numbers (P<0.01), and the significant difference was also observed in the total number of colonies between the supernatant and the enriched microbial complex (P<0.001). Significant difference between filtering method and magnetic-bead enrichment (P=0.002) for tap water, but no significant differences for drinking and bottled water (P=0.362). The colony counting and 16S rDNA gene copy number of bacteria enriched by magnetic beads were analyzed. The absolute gene copy numbers and the total number of colonies in the magnetic-bead microbial complex were significantly higher than those in the supernatant after magnetic separation (P=0.0001). This method has some high efficiency enrichment effect on microorganisms.

To better understand impacts of different pollution sources including agricultural, domestic, and landfill sources on the microbial community in the groundwater at municipal solid waste landfill sites in red beds area of Sichuan province, water quality and 16S rRNA sequencing analyses of 11groundwater samples were conducted. Groundwater quality analysis result showed that comparing to the background monitoring well (RDBJ), groundwater quality of the investigated area did not exceed the limitation (GB/T 14848-2017), however, they were affected by pollution sources in the vicinity. The major pollutants in the groundwater of landfill diffusion area (RDPD), agricultural area (RDAS), agricultural-domestic area (RDHP) were NO₃^-(P_bi=7.320) and Cl^-(P_bi=7.136), NO₃^-(P_bi=15.185), NO₃^-(P_bi=25.040)and SO₄^2-(P_bi=8.259), respectively. Microbial community diversity analysis results showed that Proteobacteria (43.6%~84.1%) was the dominant phylum, whereas Bradyrhizobium and an unclassified genus of Comanonadaceae were the dominant genera in RDAS groundwater. In RDHP groundwater, an unclassified genus of Methyococcaceae, an unclassified genus of Comamonadaceae and Sulfuritalea were the dominant genera. There was no dominant genus in RDPD groundwater, but the microbial abundancy was higher compared to the ones of the other 3groundwater types. There was no significant difference in the microbial community structures of RDPD, RDHP and RDAS. Moreover, the microbial community structures of RDPD and RDHP were similar. The impacts of environmental factors on groundwater microbial community were SO₄^2- > Cl^- > NH₄⁺-N > NO₃^--N > ORP > pH. Our results indicate that microbial community was mainly affected by the domestic and landfill pollution sources, followed by the agricultural pollution resource, and the natural factors seem to be minor factors. The results will provide a guidance for the environmental assessment and the natural attenuation remediation of groundwater contamination near the landfill sites.

Microbial fuel cells (MFCs) inoculated pure electricigenic bacteria strain Klebsiella oxytoca d7and Shewanella sp. F1 were constructed respectively, and the mechanisms of electron transfer by the electron transfer mediators (ETMs) during their electricity generation were studied. K. oxytoca d7 could only secrete ETMs during its electricigenic respiration, while the Shewanella sp. F1 could secrete ETMs during either its aerobiotic respiration, anaerobic respiration or electricigenic respiration, which indicated that the generation of ETMs was related to the species of electricigens. The redox potentials of the two species of bacteria were equivalent (-250~210mV), which were between that of the NADH and coenzyme Q in respiratory chain. The electrons intercepted by the ETMs were both denoted from the NADH on the intracellular respiratory chain, indicating that the "escape" site of the electron only depended on the ETMs itself. Under the conditions of sufficient or insufficient carbon sources, in terms of the K. oxytoca d7, the amount of electricity produced by the ETMs accounted for 60% and 41% of the total electricity generated, respectively, while that of the Shewanella sp. F1 was 57% and 50%, respectively. Electricigenic respiration of two electricigens was mainly based on the ETMs mechanism. The conversion of anode substrate and the power generation performance of the MFCs was directly affected by the process of electron transfer mediated by the ETMs.

Phanerochaete chrysosporium, one typical species of white rot fungi, was chosen as the experimental strains to investigate the effect of environmental condition on TPhP biodegradation by P. chrysosporium and the changes of cellular characteristics of P. chrysosporium during TPhP biodegradation. The results showed that the biodegradation efficiency of 5mg/L TPhP by P. chrysosporium was above 60% when inoculum size was 4% (V/V), pH was adjusted to 5~6 and initial glucose concentration was 5g/L. Cytochrome P450 of P. chrysosporium played an important role in TPhP biodegradation, the inhibition of cytochrome P450 could result in the decrease of TPhP biodegradation efficiency. In the earlier stage of TPhP biodegradation, the intracellular protein content and ATPase activity of P. chrysosporium increased remarkably to promote the metabolism and biotransformation of TPhP. Under the stress of TPhP, SOD and CAT activities of P. chrysosporium increased firstly and then decreased. There was a synergistic action between these two antioxidant enzymes in maintaining the intracellular redox balance during TPhP biodegradation.

The sediments of Baiyangdian Lake, Hengshui Lake, Yuqiao Reservoir, Songhua Lake, Dahuofang Reservoir and Xiaoxingkai Lake were selected as research objects. The contents of heavy metal elements including Cu, Zn, Pb, Cr and Ni in the sediments of the six lakes and reservoirs were determined with descriptive statistical analysis combined with multi-factor comparison of heavy metal pollution in other waters at home and abroad. The significant differences between the major sources of heavy metal pollution in the six lakes and reservoirs, the accumulation of heavy metals in the sediments and the similarities and differences with other waters at home and abroad were discussed. Heavy metal pollution in the sediments of Baiyangdian Lake, Hengshui Lake, Yuqiao Reservoir, Songhua Lake, Dahuofang Reservoir and Xiaoxingkai Lake was at a moderate to low level. There were differences in the main pollution sources between the six lakes. The heavy metal content of the sediment did not show a clear upward trend. Sediment heavy metal (Zn, Pb) are enriched in the six lakes, But the Pb content decreased compared with historical data, and the zinc content is generally higher than other regions. Dahuofang Reservoir sediments had the most heavy metal pollution. The average values of Cu, Zn, Pb, Cr and Ni were 56.28mg/kg, 142.3mg/kg, 17.44mg/kg, 97.9mg/kg, 44.44mg/kg respectively. Xiaoxingkai Lake has the lowest heavy metal content. The average values of Cu, Zn, Pb, Cr and Ni are 2.41mg/kg, 63.90mg/kg, 13.37mg/kg, 56.36mg/kg, 26.09mg/kg respectively. Comprehensive risk assessment of the six lakes and reservoirs, Dahuofang Reservoir> Yuqiao Reservoir> Baiyangdian Lake> Hengshui Lake> Songhua Lake> Xiaoxingkai Lake. The overall potential ecological risk index of heavy metals is low.

In order to investigate the spatial distributions and potential origins of heavy metals in the water bodies of Nanchang section of the Fuhe River, 23 surface water samples and 8 groundwater samples were collected in August of 2019. Seven heavy metals, namely:vanadium (V), manganese (Mn), barium (Ba), iron (Fe), strontium (Sr), zinc (Zn), and metalloid arsenic (As) were analyzed. Seven heavy metals generally had similar distribution patterns in water bodies, showing higher concentrations in the midstream and downstream portions of the river as compared to upstream part. The spatial difference of water pollutions was shown to be in middle and higher levels. Average concentrations of V, Fe and Mn in the surface water were higher than their thresholds set for centralized drinking water standard, as specified in the environmental quality standard for surface water (GB3838-2002). Average concentration of As in groundwater exceeded the threshold set for water quality standard class Ⅲ (GBT14848-2017). Multivariate statistical analysis showed that Sr, Ba and Mn probably mainly originated from the human discharges and industrial sewage, while Fe, V and Zn might be derived from the agricultural, fishery and traffic pollutions. Arsenic contaminations mainly be attributed to rocks and debris occurring in river bank and sediments at the bottom of the river.

In order to better understand the changing process of precipitation stable isotope and its influencing factors in arid inland river basins, based on the oxyhydrogen stable isotope data and corresponding meteorological data of 497 precipitation samples from 8 stations in desert area, oasis area and mountain area of Shiyang river basin from July 2013 to July 2014, the spatiotemporal change, environmental effect and water vapor source of precipitation stable isotope of Shiyang river basin were studied. The slope and intercept of the local atmospheric water line in Shiyang river basin showed the trend of low in summer and high in winter. The stable isotope of precipitation showed the trend of high in summer and low in winter, the value of stable isotope decreased with the increase of altitude from desert area, oasis area to mountain area, and the altitude effect was -0.22‰/100m, which was another manifestation of the temperature effect. The stable isotopes of precipitation in the basin showed significant temperature effect with a variation range of 0.43‰/℃, and the precipitation effect was shown under the influence of monsoon water vapor and precipitation washing process on the weather scale. The source of precipitation in the basin was mainly controlled by the west wind water vapor, summer and winter will also be affected respectively by the monsoon water vapor and the polar air mass.

Anthropogenic phosphorus pollutants have become a major driving factor for water eutrophication. In order to investigate the impact of human activities on the phosphorus input into the Xiangxi River Watershed, i.e., the first tributary in the Three Gorges Reservoir Area, statistical data at a township-level were collected from 2001 to 2019, and other related parameters were obtained from relevant literature. The Net Anthropogenic Phosphorus Inputs (NAPI) of the watershed were simulated and their spatio-temporal characteristics were analyzed. The results showed a declining trend for the NAPI of the Xiangxi River Watershed, and a distribution pattern of being higher in the northeast and lower in the southwest. Huangliang, Xiakou, and Zhaojun townships had the highest NAPI inputs into the Xiangxi River Watershed, accounting for 63.8% of the total. The percentage of NAPI removed from the Watershed by the Xiangxi river ranged between 10.7% and 79.5%. A detailed analysis demonstrated that phosphate fertilizer contributed most of the NAPI into the Xiangxi River Watershed, accounting for 46%~68% of the total. The second and third most important input sources were phosphorus pollutants from food waste and from the chemical industry, accounting for 14%~32% and 16%~24%, respectively. Furthermore, there was a significant positive correlation between NAPI and population density as well as between NAPI and the proportion of the total land area that was under cultivation (P<0.001). There was no significant correlation between NAPI and river phosphorus output (P>0.05) suggesting that there was no direct response. These results suggest that, when managing phosphorus in the Xiangxi River Watershed priority should be given to key township areas (Huangliang, Xiakou and Zhaojun), to controlling the application of chemical fertilizer, and to improving the emission standards for pollutants from factories.

In order to understand the interactions between different water level conditions and water quality of Pengxi river, provide scientific supports for rivers ecological management of the Three Gorges Reservoir, we conducted a study to determine the spatial and temporal differentiation of water quality in Hanfeng and Gaoyang Lakes. We arranged 14 sampling sites in these two lakes and measured 10 water quality parameters once amonth from December 2018 to Octorber 2019 at these sites. Single pollution index results suggest that the water quality grade of Hanfeng and Gaoyang lakes were Class Ⅲ of the National Surface Water Standard in most months. As phytoplankton blooms occured, heavy rainfall made runoff increases, the water quality grade reached ClassⅣandⅤin spring and summer.Using the Discriminant Analysis(DA) and Analysis of Variance(ANOVA), water quality showed spatial and temporal differentiation pattern, SD, DO, EC, pH, T, depth, TOC, TN and NH₃-N were the indicative factors describing the significantly spatial-temporal difference in water environment. Using the Principal Component Analysis (PCA), pollution classification factors of water environment are TN, NH₃-N, depth and pH in flow period. Otherwise, TN, TP, EC were pollution classification factors in wet period and depth, EC, TOC, TP, TN, NH₃-N were pollution classification factors in dry period. In temporal terms, the order of pollution was storage period > falling stage > discharge period in Hanfeng Lake and discharge period > falling stage > storage period in Gaoyang Lake; the spatial pollution situation was HF3 < HF1 < HF2 < HF4 < HF5 < HF8 < HF7 < HF6; GY2 < GY3 < GY1 < GY5 < GY6 < GY4.

Kuitun area in Xinjiang is the firstly reported endemic arsenic poisoning area in mainland China. Based on 3D-EEM and parallel factor analysis (PARAFAC) for high arsenic groundwater samples collected from Kuitun Xinjiang, the role of arsenic migration and transformation dissolved organic matter (DOM) characteristics and sources in the area was explored. The results indicated that the arsenic content of groundwater was in the range of 1.30~400.68μg/L, with an average of 61.18μg/L, and high arsenic groundwater accounted for 68.99% among all the samples. Three fluorescence components in the groundwater were identified as DOM including humic-like components C1 (260(325)nm/425nm),the microbial tryptophan C2 (275nm/350nm), and a humic-like (microbial reduced quinones) component C3 (260(375)nm/475nm), accounting for 2.78%, 18.74% and 54.12% respectively. The DOM fluorescence index of the water in Kuitun area was between 1.2~1.52, with a mean of 1.36, the DOM was mainly generated from terrestrial sources. The groundwater is weak alkaline-reduced environment. The release process of arsenic in groundwater is mainly the reduction of iron oxide minerals and desulfurization acid. DOM in water is involved in the reduction reaction process of iron and sulfate. The microbial tryptophan C2 acts as an electron donor during microbial respiration. The microbial reduced quinones C3 acts as an electron shuttle in the process of electron flight, enhancing the arsenic migration properties from aquifer deposits to groundwater.

The effects of nitrate on the spectral characteristics and complexation ability of DOM with Cu²⁺ in the secondary effluent of municipal wastewater were investigated by using three-dimensional fluorescence and UV spectrophotometry. The fluorescence peak representing the protein-like (tryptophan-like) produced by complexation of DOM and Cu²⁺ disappeared with the increase of NO₃^- concentration, and the right side of the UV absorption peak occurred red-shift. The concentration of NO₃^- was significantly positively correlated with the values of HIX, α₃₀₀, α₂₅₀/α₃₆₅, E₃/E₄ and UV₂₅₃/UV₂₀₃ after complexation of DOM with Cu²⁺, while negatively correlated with BIX (r with -0.958~-0.719). It had an exponential increase with S_240-400 (R² with 0.9678~0.9952) and an exponential decrease with S_275-295 (R² with 0.9965~0.9978), but had little effect on the values of FI, α₃₅₀, α₃₅₅ and S_350-400. The conditional stability constant lgK of ultraviolet humus-like, visible humus-like and high excitation wavelength tryptophan-like in the secondary effluent of DOM with Cu²⁺ were 2.08~2.46L/mmol, 1.84~2.51L/mmol and 2.27~2.57L/mmol, respectively; and the proportion of coordination fluorescent functional groups were 19.5%~36.5%, 22.5%~33.3% and 24.4%~29.2%, respectively. In summary, there was not significant difference in the intensity of the complexation reaction between Cu²⁺ and humus-like or protein-like from DOM of the secondary effluent. When the NO₃^- concentration in the samples was different, there were some uncertainties in expressing the content of DOM and molecular properties with partial fluorescence (HIX) and ultraviolet parameters (α₃₀₀, α₂₅₀/α₃₆₅, E₃/E₄, S_240-400 and S_275-295).

Fluorescence properties of the macrophytes-derived dissolved organic matter (DOM) and the interaction between Cu-binding and macrophytes-derived DOM under the influence of microbial degradation were studied by microbial degradation experiments and fluorescence titrimetric method. Three-dimensional fluorescence spectra combined with PARAFAC analysis showed that macrophytes-derived DOM contained three fluorescence components, i.e., humus-like components C1, C3, and protein-like components C2, and it was dominated by protein- and humus-like components before and after microbial degradation, respectively. 2D correlation spectra (2D-COS) showed that the protein-like substances were more sensitive and had faster degradation rate in the process of microbial degradation compared with the humus-like materials. Meanwhile, with the increasing concentration of Cu²⁺, the intensity of all fluorescence components was significantly quenched before and after microbial degradation. Compared with the protein-like components, the logKa values of humus-like components of macrophytes-derived DOM before microbial degradation was significantly larger, indicating that humus-like components had a higher metal-binding capacity than protein-like components. However, the logKa values of humus-like components in DOM were smaller than that of protein-like components after microbial degradation. Microbial degradation has a significant impact on the spectral properties and metal-binding capacity of macrophytes-derived DOM, which is meaningful to the bioavailability and ecological risks of heavy metals in lakes.

Thermal activated coal gangue and lanthanum modified coal gangue were used in the experiments of phosphorus removal and fixation in closed water. 16SrRNA high-throughput sequencing technology was used to analyze the changes of microbial community structure, phosphorus accumulating microorganisms and phosphorus metabolism function genes in sediment. Lanthanum modified coal gangue had the best removal ability of total phosphorus (TP) from the overlying water. The concentration of TP in the overlying water was 0.023~0.028 mg/L in the stable period, which was 83.5% lower than that in the control group. The removal ability of TP from the overlying water by thermal activated coal gangue was poor and its concentration in the overlying water in the stable period was about 0.15mg/L, which was slightly lower than that in the control group. Thermal activated coal gangue and lanthanum modified coal gangue both improved the microbial diversity in the sediment.Proteobacteria and Chloroflexa were the dominant bacteria in the sediment. The phosphorus accumulating organisms in the sediment in different treatment groups were Tetraspeaera and Candidatus_Accumulibacter, and their relative abundance was significantly reduced by lanthanum modified caol gangue.these two modified coal gangue both had little effect on polyphosphate kinase (PPK), but an obvious inhibition on polyphosphate exonuclease (PPX) especially for thermal activated coal gangue.

The efficiency of algae removal of a novel Pt/Ti-Fe@Fe₂O₃/ACF/Ni electrochemical system with an iron-loaded activated carbon fiber (ACF)/nickel foam (Ni) composite cathode formed by loading Fe@Fe₂O₃ nanowires on ACF/Ni with chemical impregnation method and Ti-based platinum (Pt/Ti) anode was investigated without oxygen supply and under different iron loads and initial pH condition and compared with other electrochemical systems. And the corresponding reaction mechanism of Pt/Ti-Fe@Fe₂O₃/ACF/Ni neutral electrochemical system was studied based on the indirect measurement of ·OH, analysis of the concentration of iron ion and H₂O₂, pH value, and measurement of ·O₂^-. The algae removal efficiency of the novel electrochemical system could reach 92.3% under the condition of 0.03g FeCl₃×6H₂O addition at the preparation stage of the cathode, the initial algal concentration of 0.7×10⁹~0.8×10⁹cells/L, the current density of 75mA/cm², and initial pH value of 6.2 after electrolyzed for 60min. In the Pt/Ti-Fe@Fe₂O₃/ACF/Ni electrochemical system, a large number of ·OH and ·O₂^- were produced around the Fe@Fe₂O₃/ACF/Ni cathode through the electrochemical reaction, which could make algal cells to break down and die. The primary mechanism of algae removal in this system could be the heterogeneous Electro-Fenton reaction.

Achievements have been made on the research in the influence of light on the algal growth. While the mechanism of the influence remains unclear in many aspects. The dynamic growth of Scenedesmus quadricauda cells was observed with the parallel plate flow chamber device and the computer vision technology in the study. The effect of different light intensity on the growth of Scenedesmus quadricauda were studied at a single cell scale. The individual growth curve model of Scenedesmus quadricauda has been established, which fitted the measured data well. The results showed that the largest maximum volumic growth rate of algal cells appeared under 8000lux light intensity, which could be regarded as the optimal light intensity for Scenedesmus quadricauda. The appropriate light conditions could increase algal cell's size before division. The algal cell's size before division increased with the increase of light intensity when it was lower than 8000lux. While the size decreased with the increase of light intensity when it was higher than 8000lux. In addition, higher light intensity was advantageous for an algal cell to adapt to the new environment and to reduce the time required for the algae recruitment.

As emerging environmental contaminants, microplastics (MPs) may cause potential hazard to global ecosphere (including water, soil and air) and human health. Here, we summarize the recent advances on the field of airborne MPs, including the methods of sampling and characterization, patterns of distribution and migration, toxic effects and corresponding mechanisms. To date, the quantitative characterization of airborne MPs mainly depends on stereomicroscopy, and the qualitative analysis of them is mainly conducted by Fourier infrared spectroscopy and Raman spectroscopy. Airborne MPs are widespread in global cities, seas, and even remote mountains. HYSPLIT4 and settling calculations back-trajectory modeling preliminary revealed the transport of airborne MPs. Risk assessment shows that human (especially children) body can inhale abundant airborne MPs. Future research should pay attention to exploit more precise, efficient and economical instruments and methods for airborne MPs, facilitate the standardization of quantitative data, and reveal the toxic effects and corresponding mechanisms of MPs and their absorbed pollutants at the cell, tissue, and organ levels.

In order to cope with the challenge of simple methods for Pb²⁺ detection, a novel ultra-sensitive, highly specific surface plasmon resonance (SPR) biosensor was developed. Thiolated GR-5DNAzyme was used for specific recognition of Pb²⁺ and immobilized on the SPR sensor surface. Substrate functionalized gold nanoparticles (S-AuNPs) were used for signal enhancement and hybridized with DNAzyme for the formation of the Pb²⁺ sensing layer. The enhancement of SPR signal was induced by the mass of AuNPs and the coupling effect between their local surface plasmon resonance (LSPR) and the SPR propagated on the chip surface. In the presence of Pb²⁺ ions, the substrate cleavage was catalyzed by DNAzyme, resulting in the removal of AuNPs and the significant weakening of SPR signal. The sensor surface was characterized and analyzed using X-ray photoelectron spectrometer and field emission scanning electron microscope, and the detection mechanism was verified. The biosensor incorporating 1 μmol/L DNAzyme showed the best Pb²⁺ detection performance. Its detection limit was 80pmol/L, and the SPR angle shift demonstrated a linear relationship with the logarithm of Pb²⁺ concentration in the range of 10~100nmol/L. It also showed good specificity against highly concentrated other metal ions. These results of Pb²⁺ detection in tap water and ground water showed good consistency with the ICP-MS measurements. This Pb²⁺ detection method features high sensitivity and specificity, and may have application prospects for onsite detection due to its simplicity.

The effects of sulfonamides (SAs) and silver nanoparticles (AgNPs) on plasmid RP4 conjugative transfer and mutation were investigated using Escherichia coli (E. coli) as model organism. And the combined action modes of the two antibacterial agents were judged. Based on molecular docking and linear regression, the mechanism of the two effects and their relationship with toxicity were discussed. The results showed that the tested 12 SAs and AgNPs could promote conjugative transfer and mutation in the low concentration range whether under single or combined exposure to E. coli. Among the 12 groups of SAs-AgNPs mixtures, the maximum and minimum peak values of conjugative transfer frequency promotion rate were 105.32% and 46.96%, respectively, and the maximum and minimum peak values of mutant promotion rate were 1410.25% and 238.38%, respectively. The joint effects of SAs and AgNPs to plasmid RP4 conjugative transfer and mutation effect were mainly synergistic and antagonistic, respectively. Furthermore, there was a good correlation among conjugative transfer effect, mutation effect and toxicity effect. This paper provides a reference for the study of the emergence and dissemination of bacterial resistance.

Take the advantage of design flexibility of polymer matrix composites 3D printing, the visible light-responsive ZnO/g-C₃N₄ catalyst was incorporated into ABS plastic to form a photocatalytic system with uniform and stable catalyst distribution. The reactor structure was optimized using Computational Fluid Dynamics simulation and the photocatalytic reactor was used to treat virus aerosols in relatively closed indoor areas. Results showed that viruses were more resistant than bacteria, and the addition of spiral baffles can increase the removal rate of virus aerosols, due to the significant improvement in the mass transfer performance of photocatalytic system. The spiral photocatalytic system can efficiently remove high-concentration virus (MS2, PhiX174phage) and bacterial (E. coli) aerosols with the help of commercial LED lights. Furthermore, photocatalytic system can remove virus aerosols and bacterial aerosols at a residence time of 3.75min.

The effects of particulate matters (PM_2.5, PM_C, PM₁₀) on the number of outpatient visits due to acne were studied during dust weather and non-dust weather, as well as to filter out the sensitive population by gender and age stratification. By collecting data on the concentration of particulate matters, i.e., PM_2.5, PM_C, PM₁₀, as well as the corresponding meteorological data and the outpatient data of visits due to acne at 3 first-class grade three hospitals during dust weather and non-dust weather in Lanzhou between 2013 to 2017, the relationship between particulate matters concentration and daily outpatient visits due to acne and its lagging effect were analyzed using distributed lag non-linear model (DLNM) based on Poisson distribution to constrain meteorological factors, seasonal and long-term trends, the day of week effect and other confounding factors. During the dust weather, the average daily outpatient visits due to acne at 3 first-class grade-three hospitals in Lanzhou were 26 person-times, ranging from 3 to 54 person-times; during non-dust weather, the daily outpatient visits due to acne were 37person-times, ranging from 1to 89person-times. According to the results of the single-pollutant model, the effects of PM_2.5, PM_C and PM₁₀ all peaked on lag6; for every 10μg/m³ increase in their concentration, the excess risk (ER) and 95% confidence interval (95%CI) of visits for acne were 1.065 (95%CI:0.260~1.877), 0.355 (95%CI:0.018~0.693), and 0.310 (95%CI:0.054~0.567) respectively, and PM_2.5 presented the most significant effect on the outpatient visits for acne. Analysis of different gender and age indicated that, PM_2.5 has a statistically significant effect on women, and for every 10μg/m³ increase in the concentration, the visits due to acne increased by 1.077 (95%CI:0.124~2.039); the 0-18-year-old group was significantly affected by PM_C and PM₁₀, the 19-24-year-old group was significantly affected by PM_2.5 and PM₁₀, while no statistical significance was found in the effect of particulate matters on the 25-34-year-old group as well as the ³35-year-old group. During non-dust weather, PM_2.5, PM_C and PM₁₀ did not increase the outpatient visits for acne. The double/multi-pollutant model demonstrated that after adjusting other pollutants, PM_2.5, PM_C and PM₁₀ had the similar effects on the outpatient visits for acne as the single-pollutant model, which were still statistically significant. Hence, it can be concluded that, the increments in particulate matters (PM_2.5, PM_C, PM₁₀) are likely to increase the risk of acne during dust weather in Lanzhou and have a significant effect on women and adolescents.

In view of the low concentration of influent water, which affects the emissions reduction potential and economic benefit of sewage treatment plant, taking Kunming as an example, a simulation model of urban drainage system based on system dynamics was set up. According to the targets of the 13th Five-Year Plan of Kunming, this paper designed four emissions reduction scenarios based on 2015 as the base year, and then simulated and predicted the emissions reduction potential and cost and benefit of sewage treatment plants under different scenarios in different periods. The urban drainage network reconstruction and strengthening management was very important to improve the efficiency of sewage treatment plant and fully tap the potential of pollutant treatment. Compared with the benchmark scenario, the reduction of COD in the short-term and long-term increased by 314772t and 389126t, respectively; the reduction of NH₃-N in the short-term and long-term increased by 24223t and 27234t, respectively; the cost-benefit ratio of the sewage treatment plant in the short-term and long-term reduced by 0.2 and 0.17, respectively. Emissions reduction potential was fully tapped and the economic benefit is obviously improved.

The RAM-SFA-RAM three-stage industrial green total factor water efficiency measurement model was constructed, and the efficiency values of different levels were evaluated and compared. Moreover, the driving mechanism of industrial green total factor water efficiency was empirically analyzed based on Tobit model. The efficiency measurement results showed that environmental factors and statistical noise were important factors that should not be ignored in the calculation of efficiency values. In the period of 2000~2017, the efficiency value of the national sample continued to rise, but there was still a big gap between the perfect development status, and its development stage could be specifically divided into "stable increase period", "vibration period" and "speed increase period". In the regional efficiency analysis, the eastern efficiency had a relatively significant leading edge, while the efficiency difference between the central and northeastern regions was smaller, and the variation curve had obvious "interactive" phenomenon, while the overall efficiency was lower in the west. In the inspection of major economic belts, the efficiency of the Beijing-Tianjin-Hebei region was higher than that in the Pan-Pearl River Delta and Pan-Yangtze River Delta regions. Additionally, the driving mechanism analysis showed that water resources endowment, enterprise technology innovation, water consumption structure and environmental regulation based on the national sample dimension had positively promoted the industrial green total factor water efficiency, while the industrial structure and urbanization rate showed a negative inhibition effect. In the regional sample analysis, there were some differences in the effects of the various influencing factors between different regions, but the industrial structure adjustment and urbanization level should be taken seriously, and different regions needed to take targeted improvement measures based on their actual characteristics.

Taking into consideration the problems caused by insufficient representation of water quality monitoring stations in previous research methods, a system of research methods suitable for surface-water background values in Northeast China was established, considering the spatiotemporal characteristics of water background values. Source water reserves in Heilongjiang Province was selected as the study area, water quality monitoring stations set up randomly in the area were divided into control units according to DEM data, and a model to quantitatively determine the background characteristics of these stations was established by extracting the relevant indicators in each unit. Based on the results, a surface-water background value monitoring program was proposed, and a database of the background values was developed. The study area's natural and spatial attributes were selected and spatial overlay technology and cluster analysis method were used to divide its surface-water background values, based on which Heilongjiang Province was eventually divided into six geographical areas. Furthermore, the characteristic range of surface water background values of each geographic area was calculated and it was found that the surface-water background values in the protected area exceeded the standard limit of Class Ⅱ water quality. Finally, a method for assessing the water quality using the background values was proposed and applied to the study area. The results show that the method is feasible and superior to the single-factor assessment method. The research results can provide scientific data support and theoretical basis for regions to develop water environment assessment methods under the influence of background values.