Based on the O₃-8h data of 13 cities in Beijing-Tianjin-Hebei region from 2014 to 2017, the temporal variation and pollution characteristics of O₃ were analyzed. In addition, the relationship between the O₃ concentration and the meteorological factors was studied by combining with the meteorological data of the same period. O₃-8h in Beijing-Tianjin-Hebei region increased from 2014~2017, with an average annual increase of 4.50μg/m³.O₃ pollution situation in the whole region aggravated, especially in Beijing and Baoding. The monthly O₃ concentration and the over-standard situation mainly presented single-peak variations in 2014~2015, with the maximum in May. However, the irregular double-peak variations were found in 2016~2017,showing one peak value during May to June and the other in September. The correlation between O₃ concentration and meteorological factors indicated that the influence of meteorological factors on O₃ had obvious seasonal differences. In spring, summer and autumn, the temperature was the main factor affecting O₃ concentration, while the relative humidity and wind speed were the main factors in winter. Besides, it is indicted that the thresholds for the formation of high O₃ concentration in Beijing, Tianjin and Shijiazhuang were different in summer.

Based on observing data of aerosol number concentration and meteorological parameters in December 2017 in Nanjing, the diurnal variations and differences of 10~1000nm nanometer aerosol spectra were compared and studied in sunny and fog-haze days. The results showed that there was a significant relationship between the occurrence of unimodal distribution and pollution aggravation, which occurred in the sunny afternoon, haze serious pollution and pollution dissipation stage, and dense fog process, respectively. The peak particle sizes were sunny days (20~100nm), haze days (27~144nm) and foggy days (34~122nm). Under three weather conditions, strong solar radiation and low humidity in sunny days were suitable for the generation of small particles, and the proportion of nuclei mode was the highest in sunny days. The meteorological field in haze days was suitable for the stable existence of a large number of particles, and the proportion of Aitken mode was highest in haze days. A large amount of aerosols had hygroscopic growth in foggy days, resulting the proportion of accumulation mode was highest in foggy days. During the pollutant accumulation phase in haze days, the collision and growth effect of a large number of accumulated particles on nuclei and Aitken particles inhibits the generation of nuclei and Aitken particles. The variation rate of nuclei and Aitken mode particles concentration was -91.0% and -62.5%, while that of the accumulation mode particles was 89.7%. Fog removal was most effective on Aitken particles.

The chemical composition and optical characteristics of single particle aerosols were observed using a single particle aerosol mass spectrometer (SPAMS), nephelometer and aethalometer at the Heshan Atmospheric Supersite in Guangdong from October to November in 2014. Single particles were classified into 9classes by Art-2a classification method including organic carbon-sulfate/nitrate particles (OC-Sulfate/Nitrate), elemental carbon-sulfate/nitrate particles (EC-Sulfate/Nitrate), elemental and organic carbon-sulfate/nitrate particles (ECOC-Sulfate/Nitrate), high molecular organic carbon particles (HOC), sea salt particles (Sea-salt), silicate particles (Si-rich), levoglucosan particles (Lev), potassium-sulfate/nitrate particles (K-Sulfate/Nitrate) and metal particles (Metal). The absorption coefficient, scattering coefficient and single scattering albedo (SSA) of the aerosols significantly increased from clean to haze periods. The aerosol extinction ability enhanced along with the percentage of EC-Sulfate/Nitrate particles decreased from 34.8% to 31%, and OC-Sulfate/Nitrate particles increased from 9.9% to 23.6% as well as K-Sulfate/Nitrate particles increased from 8.5% to 14%. Besides, the OC-Sulfate/Nitrate particles were internally mixing with sulfate, nitrate and ammonium in the haze period, suggesting the aged OC-Sulfate/Nitrate particles and K-Sulfate/Nitrate particles had a large contribution to the increase of aerosol extinction coefficient. The aerosol scattering coefficient and absorption coefficient enhanced as the increase of RH from 50% to above 70%, and the extinction coefficient increased from 326.1Mm^-1 to 362.9Mm^-1, while the SSA decreased. The PM_2.5 mass extinction efficiency increased from 4.98 to 5.99, and the percentage of EC-Sulfate/Nitrate and K-Sulfate/Nitrate particles decreased, while the proportion of OC-Sulfate/Nitrate particles increased from 7.79% to 14.29%, indicating the increase of aged OC-Sulfate/Nitrate particles mixing with sulfate, nitrate and ammonium salts has an important impact on the enhancement of the aerosol extinction coefficient under high RH conditions.

Simultaneous pollution events of PM_2.5 and O₃ (PM_2.5-O₃ compound pollution) in Shanghai from 2013 to 2017 and the relationship between PM_2.5-O₃ compound pollution and meteorological conditions were statistically analyzed. In the past five years, PM_2.5-O₃ compound pollution events accounted for 33.4% of total O₃ pollution events in shanghai, which only appeared between March and October and decreased by year. The peak O₃ concentration and average O₃ concentration during PM_2.5-O₃ compound pollution were higher than those during simplex O₃ pollution. The duration of O₃ pollution during PM_2.5-O₃ compound pollution events was longer than that of simplex O₃ pollution. The main meteorological reasons were ground convergence and low boundary layer height. The weather situation of PM_2.5-O₃ compound pollution was related to weak pressure field, which was categorized into 5weather types, namely bottom of low pressure, front of low pressure, top of high pressure, rear of high pressure and equalized pressure. The equalized pressure mostly appeared, which accounted for 53%. The PM_2.5-O₃ compound pollution required strict meteorological threshold ranges, which were more conductive to PM_2.5 concentration increasing than to O₃ concentration increasing. When the temperature was between 27.9~34℃, the humidity was between 43%~58%, the wind speed was between 2.1~3.3m/s, the height of the mixed layer was between 1122~1599m, and when there was convergence, it was the most conductive to the occurrence of PM_2.5-O₃ compound pollution.

The characteristics of the pollution process occurred in Beijing, Tianjin and Hebe province during 16~21 December 2016, the relationship between the pollution process and meteorological conditions were studied by using the data of routine ground observation, Micropulse Lidar (MINI-MPL), wind profiler radar, and atmospheric composition of the Ministry of Ecology, etc. of China Meteorological Administration. The static state of the atmosphere, the prevailing southerly airflow in the lower atmosphere, the continuous increase of atmospheric humidity, and the special terrain surrounding the mountains on three sides of Beijing which was not conducive to the diffusion of pollutants were the important factors causing the serious air pollution in Beijing. During the period of heavy pollution, the pollutants mainly accumulated below 800 meters. When the pollution was serious, the height of pollutants was only about 400 meters. Wind profiler radar retrieved wind field showed that the low level of PM_2.5 concentration rose rapidly during two periods, accompanied by persistent southerly or easterly winds. During the pollution process, the inversion structure was obvious, and the rapid development of two pollution stages occured in the two periods of the strongest inversion. In this polluted weather process, the depolarization ratio of lidar was less than 0.25, reflecting that the pollution was mainly caused by human activities. In the early stage, primary particulate matter was the main pollutant, and in the later stage, secondary transformed particulate matter was the main. The depolarization ratio showed obvious daily change in the early stage of pollution process, and the depolarization ratio was higher in daytime than at night.

In order to analyze the two heavy pollution processes in Beijing-Tianjin-Hebei area from November 27 to December 1 (process 1) and December 19 to 25(process 2), 2015, the formation mechanism of heavy pollution weather was analyzed from circulation situation, atmospheric stability condition, dynamic condition, water vapor condition and near-surface wind field transportation. These two heavy polluted weather processes belonged to stationary type, and the duration of heavy polluted weather in Beijing, Tianjin and Hebei was more than 50%. In the presence of large-scale static and stable situation, the vertical diffusion condition in the boundary layer during process 1 was weaker than that of process 2. During the first period of the process, the position of the surface convergence line was northward and remains unchanged, while the position of the convergence line was south and slightly north-south oscillation during the second process, which resulted in the difference of heavy pollution area and pollution growth rate between two processes. For Beijing, snowfall melting provided favorable water vapor conditions in the early stage of process 1. Weak southerly wind was beneficial to the transport of pollutants and water vapor. The height of mixing layer remained abnormally low (the average height of mixing layer in Beijing, Tianjin and Hebei was 339m), accompanied by weak subsidence movement (0~2Pa/s) and multi-layer inversion (and thickness) during the process, which caused no obvious diurnal variation. Simultaneously, the surface convergence line maintained in central Beijing. Due to these multiple factors, Beijing was seriously polluted in process 1 with peak concentration of PM_2.5 reached to 593mg/m³. In the early stage of process 2, emission reduction measures were adopted, visibility and PM_2.5 changed greatly, and pollution development was more gentle than that of process 1. In the later stage of process 2, adverse meteorological conditions combined with pollution emissions resulted in the explosive growth of PM_2.5, with the peak concentration of PM_2.5 in Xingtai reaching 700mg/m³ and the growth rate exceeding 7.2mg/(m³·h).

Gaseous elemental mercury (GEM) was monitored continuously at Wuyi Mountain using the high-resolution automatic atmospheric mercury vapor analyzer (Tekran 2537B) from June 2017 to May 2018. The annual mean concentration of GEM was (1.70±0.43)ng/m³, slightly higher than background level in the northern hemisphere, suggesting that the atmosphere of the Wuyi Mountain was polluted to some extent. The GEM varied in different seasons, with the highest concentration observed in winter, followed by fall, spring, and summer. The monsoon and wind speed contributed mostly to the seasonal variation. Different diurnal variation characteristics of GEM were found in four seasons. In spring and autumn, GEM continued to decrease after 8:00am, however, in other seasons, GEM showed "increase-decrease-increase" and peaked at different times in nighttime. The GEM in the daytime were generally higher than those in the nighttime, which may related to the wind speed and long distance transport of mercury. Backward trajectory and concentration-weighted trajectory indicated that polluted air masses to the Wuyi Mountain via Jiangxi province under westerly wind was the main path of atmospheric mercury migration. In addition, Jiangxi province and north-central Fujian province were the potential source areas of GEM at the Wuyi Mountain. The values of △GEM/△CO suggested that mercury pollution at the Wuyi Mountain was mainly affected by anthropogenic mercury emissions, while biomass burning did little contribution.

PM_2.5 emissions from iron and steel and nonferrous industries as object, based on the discrete particle model DPM and UDF custom programming, The effects of inlet velocity, particle diameter, external magnetic field strength, magnetic fiber magnetic flux density and magnetic susceptibility on the capture efficiency were studied and analyzed by combination between the particle motion trajectory and force. The results showed that when 0.5μm£d_p£2.5μm, v=0.1m/s, the efficiency of single fiber to capture PM_2.5 could be improved by using high gradient magnetic field(H=0.1T, B=0.06T)4.23times. It was also found that there were two gravitational zones and two repulsive zones around the magnetic fibers. At the same time, in the high gradient magnetic field, the capture efficiency of the magnetic fiber to PM_2.5 decreased first and then stabilized with the inlet velocity; while the capture efficiency increased first and then decreased with the particle diameter of the dust. When d_p=1.0μm, the increasing of capture efficiency was maximized at this time; whether it was the external magnetic field strength or the magnetic fiber magnetic flux density, the capturing efficiency of magnetic fiber to particles was a linear function of the field intensity, with the efficiency growth rate of K_B>K_H; with the increase of the magnetic susceptibility of the particles, the capturing of particles by magnetic fibers presented a two-stage linear growth law, and the growth rate K₁>K₂. When the particles passed through the high gradient magnetic field, the inlet velocity, dust particle diameter and field strength had a great influence on the motion trajectory, while the magnetic susceptibility had little effect on the motion trajectory.

A single metal Pd/γ-Al₂O₃ catalyst and a bimetallic Pd-Ce/γ-Al₂O₃ catalyst were prepared by equal volume impregnation method to investigate the effect of CeO₂ doping on the catalytic oxidation of toluene. The specific surface area, surface morphology and redox properties of the catalyst were characterized with N₂ desorption, SEM and H₂-TPR. It was found that the doping of CeO₂ reduced the specific surface area of Pd/γ-Al₂O₃ catalyst to a certain extent, but increased the pore density of 10nm, and the catalyst still maintained the mesoporous structure. When 4% CeO₂ was added (mass fraction, the same below), the specific surface area of ??the catalyst was reduced to 165m²/g, and there was a certain degree of clogging in the pores, which hindered the diffusion of pollutants and reaction products, and reduced the catalytic performance of the catalyst. The H₂-TPR results showed that there is a strong synergistic effect between Pd and Ce. CeO₂ adjacent to PdO was more likely to open Ce-O bond, which was 0.3compared with single metal 0.2% Pd/γ-Al₂O₃ catalyst. The catalyst of%CeO₂ had a stronger reduction peak, indicating that the introduction of CeO₂ provided more surface oxygen vacancies for the catalyst and enhances the catalytic oxidation ability of the catalyst. in which the T₁₀ and T₉₀ were reduced by 10℃ and 40℃ respectively.

The feasibility of the stable operation of a sequencing biofilm batch reactor (SBBR) for completely autotrophic nitrogen removal over nitrite (CANON) was investigated using aeration condition adjusting strategy, along with decreasing temperature and influent substrate (anammonia). The SBBR operated steadily for 223 days at 35℃ and high substrate[(446.47±43.77) mg NH₄⁺-N/L] with the aeration regime of aeration/non-aeration=60min/60min; the total nitrogen removal rate (TNRR) and total nitrogen removal efficiency (TNRE) reached (0.49±0.07) kg N/(m³·d) and (84.3±4.6)%, respectively. After temperaute decreasd to 20~23℃, the intermittent aerobic condition was changed to aeration/non-aeration=40min/80min based on the ratio of NO₂^--N accumulation rate to NO₂^--N removal rate in the single-cycles. The TNRR and TNRE decreased to (0.43±0.04) kg N/(m³·d) and (69.5±5.7)% for 67days of operation, respectively. With gradual decreasing ammonia to (105.6±16.1) mg NH₄⁺-N/L, the aeration/non-aeration time was regulated to 40min/80min, 30min/90min and 8min/32min in sequence. For 67days operation, the TNRR decreased to (0.16±0.02) kg N/(m³·d); nevertheless, the TNRE increased to (71.5±7.5)%. High-throughput sequencing results confirmed that the regulation strategy applied herein ensured the dominance of nitrogen removal functional bacterias in CANON system during decreasing temperature and substrate while the relative abundance of nitrite oxidizing bacteira was always below 0.1%.

The effective inhibition or wash-out of nitrite oxidizing bacteria (NOB) is the key challenge for the application of partial nitritation/anammox (PA/N) process in domestic wastewater treatment. The deteriorated domestic wastewater PN/A system was used to investigate the recovery effect of hydroxylamine (NH₂OH) concentration and dosing mode on it. The nitrate (NO₃^--N) production ratio of the PN/A system was 0.90, which was due to the overgrowth of NOB. The results showed that when the initial NH₂OH concentration was 10mg/L in the sequencing batch reactor (SBR) and NH₂OH was added once a day, the ratio of NO₃^--N_producted/NH₄⁺-N_consumed was decreased from 0.90 to 0.11 after adding NH₂OH for 20d. It indicated that NH₂OH (10mg/L) addition could restore PN/A process in-situ. The ratio of NO₃^--N_producted/NH₄⁺-N_consumed increased to 0.15 again after stopping NH₂OH addition for 59d. When continued to add NH₂OH into reactor for 5d, the PN/A process operated well. Therefore, the intermittent addition of NH₂OH strategy could maintain the stable performance of the PN/A process. The real-time quantitative PCR results showed that the NOB abundance was decreased continuously from (4.52±0.44)×10¹⁰copies/g VSS (Day 6) to (2.30±0.80)×10⁹copies/g VSS (Day 157) after NH₂OH (10mg/L) addition. It indicated that NH₂OH addition was beneficial to inhibit and wash out NOB.

Based on the biological and dissolution effects of electromagnetic wave on sludge, returned sludge in A²O reactor was loaded by electromagnetic wave, and effect on the function of the anaerobic tank was investigated from the perspective of microbial community diversity. Sludge flocs were decomposed, and cell structure in returned sludge was destroyed owing to electromagnetic wave loading. The dissolution ratio of C, N and P was obvious. By contrast, the enrichment effect of TP in the anaerobic tank was significantly enhanced with the enrichment rate increased from 122.9% to 152.2%. The removal rates of TN and COD increased from 7.3% and 58.8% to 32.1% and 65.4%, respectively. MiSeq pyrosequencing showed that the abundance of microbial communities in the anaerobic tank increased, while the microbial diversity decreased. Carbon resource was supplemented due to the interaction of the biological and dissolution effects of electromagnetic wave on returned sludge. Consequently, the metabolic activity of microorganisms and the number of live bacteria in the anaerobic tank increased greatly. Zoogloea, Tolumonas, Dechloromonas and other bacterial genera were enriched in the anaerobic tank.

In order to explore the feasibility of simultaneous CO₂ sequestration and N/P nutrients recovery in sludge anaerobic digestion coupled with mineral carbonation, different ratios of Mg²⁺/Ca²⁺ were added in the anaerobic digestion systems with sludge hydrolysate as substrate, to investigate the performance of simultaneous CO₂ sequestration and nutrients removal. The results showed that the addition of Mg²⁺/Ca²⁺ of (20mmol/L)/(0mmol/L), (10mmol/L)/(10mmol/L) and (0mmol/L)/(20mmol/L) could promote the degradation of organic matters, so that the biogas production increased by 16.97%, 21.56% and 23.99%, and the CO₂ content was reduced from 27.27% to 24.81%, 22.06% and 21.98%, respectively. The phosphate concentration was reduced by 63.46%~66.47% with Mg²⁺/Ca²⁺ addition of different ratios. However, ammonia nitrogen concentration was reduced only in the digesters with Mg²⁺/Ca²⁺ added at (20mmol/L)/(0mmol/L) and (10mmol/L)/(10mmol/L). XRD analysis revealed that struvite and magnesium carbonate, struvite and calcite, calcite and monetite were respectively formed in the digesters with Mg²⁺/Ca²⁺ added at (20mmol/L)/(0mmol/L), (10mmol/L)/(10mmol/L) and (0mmol/L)/(20mmol/L). The combined addition of Mg²⁺/Ca²⁺ in equimolar amount achieved the best simultaneous CO₂ sequestration and N/P nutrients recovery.

An immobilized bacteria pellet by embedding method was prepared to remove ammonia from wastewater. The preparation condition was optimized and the effects of immobilized bacteria pellet dosage, solution pH and reaction time on ammonia removal were investigated. The optimal preparation conditions were:chitosan dosage was 20g/L, sodium alginate dosage was 10g/L, target species embedding amount was 2:5 (V/V). For the treatment of the wastewater, after treated by 15g/L of immobilized bacteria pellet for 4h without adjusted the solution pH, 93.9% of ammonia can be removed from the wastewater, in which 64.3% was due to the adsorption and 29.6% was due to the microbial action. After the treatment, numbers of the bacteria in the external and internal immobilized pellets were significantly increased. Furthermore, ammonium adsorption process by the immobilized bacteria pellets could be well fitted to the pseudo-second-order kinetic model (R²=0.9252) and the Langmuir equilibrium model (R²=0.9578).

Cu₂O@ZnO composite photocatalyst was successfully prepared by improved impregnation-reduction-air oxidation method, and the photocatalytic activity and degradation mechanism of the Cu₂O@ZnO was investigated by the degradation of two different chemical pollutants (p-nitrophenol (PNP) and polyacrylamide (PAM)). Cu₂O@ZnO composite photocatalyst expressed the best photocatalytic degradation performance under the simulated sunlight when the molar ratio of copper to zinc was 0.15, the photocatalytic degradation rates of p-nitrophenol and polyacrylamide arrived at 98.2% and 99.7%, respectively. The results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), ultraviolet-visible (UV-Vis) absorption spectroscopy and so on showed that Cu₂O and ZnO formed type Ⅱ heterojunction, then the recombination of photogenerated electron hole pairs was inhibited effectively. Superoxide radicals and holes were the main active species by free radical trapping experiments, and the photocatalyst still expressed high photocatalytic activity after four cycles of reaction.

To clarify the indirect photodegradation mechanism of IBP, the indirect photodegradation behaviors of IBP were investigated in the presence of four kinds of dissolved organic matter (DOM) and were also assessed in the presence of seawater components and conditions such as salinity, pH, nitrate and bicarbonate. Firstly, the indirect photodegradation of IBP could be accelerated by the four different sources of DOM and followed pseudo-first-order kinetics, the photodegradation rate constants of APAP were found to decrease in the following order:JKHA > SRHA > SRFA > SRNOM. DOM promoted the indirect photodegradation of IBP through the formation of various reactive intermediates,·OH and ¹O₂ were the main contributors. Secondly, in the range of pH 5~11, the photodegradation rate of IBP was firstly decreased and then increased, the highest photodegradation rate of IBP was found at pH 5.0. Lastly, the photodegradation rate constants of IBP increased with increasing salinity, nitrate and bicarbonate.

The degradation efficiency and mechanism of ferrite (Fe(VI))/calcium oxide (CaO₂) combined treatment on dimethyl phthalate (DMP) were studied. Multi-factor experiments were carried out based on the Box-Behnken experimental design in Response Surface Method. Relationships between the removal rate of DMP and Fe(VI)dosage, CaO₂ dosage and reaction time were fitted by quadratic polynomial and stepwise regression method, and the experimental conditions were optimized. DMP could be effectively removed by Fe(VI)/CaO₂ under neutral pH conditions, and the degradation process conformed to the pseudo-second-order kinetic model. The maximum degradation rate of DMP predicted by the model reached 95.57% when the molar ratio of Fe(VI)/CaO₂/DMP was 1.1/4.4/1, which was close to 90.14% obtained by verification experiments, indicating that the model possessed a good simulation and predictive performance. HCO₃^- and Mg(Ⅱ) inhibited the degradation of DMP to a certain extent. The results of free radical scavenging experiments revealed that hydroxyl radical (HO·) and superoxide radical (O₂^-·) made significant contributions to the degradation of DMP, demonstrating that Fe(VI)and CaO₂ could form Fenton-like reagents to synergistically degrade pollutants. The main degradation pathways of DMP included hydrolysis of ester group, oxidation of side chain and hydroxylation of benzene rings. The main degradation products were monomethyl phthalate, 2,5-dihydroxybenzoic acid, isophthalic acid, oxalic acid, etc.

The metal organic framework HKUST-1 was prepared by solvothermal method. The tyrosine (Tyr), phenylalanine (phe) and tryptophan (Tyr) which were detected frequently in water source were selected as the targets, and their adsorption on HKUST-1 was investigated. The adsorbent characteristic of HKUST-1was analyzed by XRD and FTIR techniques. The adsorption mechanism of amino acids on HKUST-1 was investigated by adsorption kinetics, isotherms and thermodynamics. HKUST-1 had high crystallinity and good removal effects on tyrosine, phenylalanine and tryptophan, saturated adsorption capacity was up to 248.65,143.67 and 140.09mg/g; the adsorption process was in accordance with the Langmuir adsorption isotherm model and the Lagergren quasi-secondary kinetic model; adsorption thermodynamics results showed that HKUST-1 removed amino acids as an endothermic reaction; high adsorption capacity was mainly attributed to electrostatic interaction, hydrogen bonding and π-π interaction.

The conventional biochemical treatment effluent of dyeing wastewater (BREDW) still contains a certain concentration of dissolved organic pollutants (DOM) and Aniline strictly controlled by the new standard. Sodium bisulfite-activated potassium bisulfate complex salt (SO₃^2-/HSO₅^-) advanced oxidation system was used to produce sulfate radical (SO₄^-·) for the advanced treatment of BREDW. The effects of initial pH value, reaction temperature, SO₃^2-/HSO₅^-molar ratio and HSO₅^- dosage on the removal of COD and aniline were optimized based on response surface methodology. COD and aniline can be removed by the system remarkably. The contribution order of influencing factors to COD and aniline treatment were as follows:temperature>n(SO₃^2-)/n(HSO₅^-)>n(SO₃^2-)>initial pH value and n(HSO₅^-)>n(SO₃^2-)/n(HSO₅^-)/initial pH value>temperature. The removal rates of COD and aniline were 33% and 90% respectively under the experimental conditions by the experiment optimization:pH of 6.8, temperature of 53℃, concentration molar ratio SO₃^2- to HSO₅^- of 1.6 and HSO₅^- dosage of 37.1mmol/L. Further studies were made on the changes of fluorescence and molecular properties of the main DOMs before and after dyeing effluent treatment. 3DEEMs found that aromatic proteins and soluble microbial metabolites were the main components of DOM in the BREDW. The fluorescent DOM content in the oxidized effluent decreased significantly under different conditions, and the fluorescent area volume was reduced by 42.03%~77.67%. At the same time, the peak value of tryptophan (Ex/Em=230~225nm/340nm~330nm) in the oxidized effluent was observed to blue shift of 5~10nm. Polycyclic aromatic hydrocarbons in BREDW are decomposed into small molecules, the number of conjugated groups and aromatic rings decreases; GPC revealed that the proportion of macromolecules (0.45μm~100kDa) was 41%, that of medium molecules (12~100kDa) was 48.9%, that of peak molecular weight (Mp) was 56.324kDa, and that of Mw/Mn=2.168. After treatment, the effluent Mp mainly distributes in the range of 12.28~17.56kDa, with more small molecular substances, more structures and species. GC-MS synchronously reveals that the alkanes in the oxidized effluent are greatly reduced, and the main by-products are esters, alcohols and fatty acids, which can create conditions for further biochemical treatment.

Modified foam copper (MCF) with micro-electrolytic properties was prepared in this study through an improved reduction method by loading nano-zero-valent iron (nZVI) on porous copper foam (CF). The surface morphology and element distribution of CF before and after nZVI loading were analyzed using SEM, SEMMAPPING and EDX. Besides, The study investigated the effects of removal methods, MCF dosages and initial DC concentrations on the degradation of DC with nZVI loading on MCF. The removal efficiency of DC using nZVI with MCF was much better than that without MCF. When DC concentration was 50mg/L, MCF dosage was 4.0g, and the reaction time was 20min, the removal efficiency of DC could reach as high as 99%. In addition, it was found that DC degradation with MCF fitted the pseudo-first-order reaction kinetics, and the reaction rate constant k became larger with the increase of MCF dosage. When the MCF dosage was 5.0g, the maximum k value was 0.0609min^-1. Finally, the mechanism of DC degradation with MCF was explored based on all the results and it provided a certain theoretical basis for MCF practical application.

A pulsed power supply was used in capacitive deionization instead of DC power supply. A pulsed capacitive deionization cell was constructed. The removal rates of NO₃^--N and NH₃-N by pulsed-CDI and DC-CDI were compared, and within 60 minutes, a higher removal efficiency by pulsed-CDI. The removal rate of NO₃-N was the highest under 50% duty cycle and 10⁴Hz frequency. Results from molecular dynamics simulation showed that the orientation of hydrogen and oxygen atoms in water molecules was more random under pulsed electric field. Compared with DC electric field, the orientation polarization of water molecules' dipole moment was weakened and the mass transfer resistance of ions is reduced.

The uranium removal tests of inactivated and non-inactivated Lactobacillus plantarum were carried out under different pH and biomass concentration conditions, and the mechanism of uranium removal by Lactobacillus plantarum was discussed. Based on SEM-EDS, FTIR, XPS, and XRD, the microscopic mechanism of the interaction between uranium and microbial cell surface and the characteristics of sediments on the cell surface were analyzed. The ability of Lactobacillus plantarum to adsorb uranium was significantly improved after heat inactivation. With the pH 6.0, 37℃ and the 10mg/L U(VI), the removal efficiency of U(VI) by heat-killed cells was up to 94.7% during 120min, while the removal efficiency was only 88.9% by live cells. The inactivated bacteria had higher uranium adsorption capacity. At the biomass concentration of 0.06~0.24mg/L and pH value of 3.0~7.0, the rate(W) of accumulative capacity of U(VI) of inactivated bacteria to that of living bacteria is greater than 1. SEM-EDS、FTIR result illustrated the U(VI) could be adsorbed or coordinated on the surface of the active and inactivated cells through functional groups such as hydroxyl, acyl and carboxyl groups. There were 4 distinct crystal peaks of uranyl phosphate compound at 2θ(18.023, 25.492, 27.343 and 40.813°) in the XRD spectrum of living bacteria, while no crystal peaks in the spectrum of inactivated bacteria. XRD result indicated U(VI) can be precipitated with the form of uranyl phosphate by biological metabolism of live cells. There were the peaks attributed U(IV) at U 4f 7/2 with binding energy of 381.20eV and U 4f 5/2 with 390.95eV in the XPS energy spectrum of living bacteria. While There was no the peaks attributed U(IV) in the spectrum of inactivated bacteria. XPS result indicated that U(VI) can be induced to U(IV) by living bacteria.

Steel slag was firstly employed as a solid activator for a peroxydisulfate activation system, in which the degradation efficiency of BPA was evaluated. About 74% of BPA(50 μg/L) can be effectively removed within 1 hour under the adopted condition ([peroxydisulfate]₀=2g/L,[Steel Slag]=3g/L, T=25℃). The components and surface morphology of unused and recycled steel slag were analyzed by scanning electron microscopy, X-ray diffraction and X-ray fluorescence, demonstrating the gradual decrease of CaO and FeO. Radical scavenger studies confirmed that all of the O₂^·-, SO₄^·- and ·OH contributed to the BPA degradation with the contribution of 68.97%, 9.52% and 21.51%, respectively. The degradation efficiency was enhanced in tap water due to the existence of HCO₃^- and was weakened in municipal wastewater effluent due to the radical scavenge by other organics. A redox mechanism was proposed and claimed that both the base oxides and iron oxides of steel slag were responsible for the peroxydisulfate activation. The degradation products of BPA included quinone and carboxylic acid, which were identified by LC/MS.

In order to analyze the fouling characteristics of soluble microbial products (SMP) on GO/PVDF hybrid membrane, macro-fouling experiments were carried out, and the adsorption of SMP on the self-made coated chip and the structure change of the fouling layer were analyzed from the microscopic levels by the dissipative quartz microcrystalline balance (QCM-D). The results showed that membrane (GO=0.5wt%) had the highest pollution recovery rate (79.95%) with the strongest anti-fouling ability. QCM-D experiments showed that the adsorption capacity of SMP on the surface of membrane (GO=0wt%) coated chip was the largest and the fouling was serious. The stronger the hydrophilicity of membrane led to the smaller the change of adsorption frequency and the stronger the anti-fouling ability of membrane. Otherwise, it was also found that membrane (GO=0.5wt%) coated chips had loose and soft contaminant structures, and the surface of other membranes were hard and dense.

Aiming at the optimization of monitoring schemes in the process of the identification of pollution source and the inversion of aquifer parameters in the heterogeneous underground aquifer, this paper proposes an optimization method for the multi-well monitoring schemes based on Bayesian formula and progressive addition of wells with minimum information entropy. Firstly, the two-dimensional heterogeneous isotropic subsurface groundwater flow and solute transport models under hypothetical case were constructed, and the numerical simulation models were solved by GMS software. The surrogate model of the numerical simulation model was established by the optimal Latin hypercube sampling method and Kriging method. Then Taking the minimum information entropy of the parameter posterior distribution as the objective function, the optimization design of multi-well monitoring schemes was carried out by means of progressive addition of wells. Finally, the differential evolution adaptive Metropolis algorithm was used to inverse the pollution source and aquifer parameters synchronously according to the optimized monitoring scheme. The case study results showed that:The 5combination monitoring scheme (6, 5, 1, 2, 8) under the condition of taking into account the inversion accuracy and monitoring cost and ensuring that there was at least one monitoring well in each parameter section was the optimal monitoring scheme. Compared with the 10combined monitoring scheme (1, 2, 3, 4, 5, 6, 7, 8, 9, 10) with the smallest information entropy, the 11parameters posterior mean deviation rate increased by 1.2%, but the monitoring cost was reduced by 50%.

Kriging, support vector regression (SVR), kernel extreme learning machine (KELM) were applied to building the surrogate models of multi-phase flow simulation model, and set pair analysis (SPA) was applied to building ensemble surrogate models. The applicability of different surrogate models was analyzed via a comparison study. kriging model was with the highest accuracy, followed by KELM model and SVR model. Compared with Kriging model, set pair weighted ensemble surrogate model significantly improved the approximation accuracy. The mean of residuals and the mean of relative errors between ensemble model outputs and simulation model outputs were only 0.4009% and 0.5373%, respectively. Furthermore, it only took 1.5s to run the set pair weighted ensemble surrogate model. Replacing the simulation model with an ensemble surrogate model considerably reduced the computational burden of the simulation-optimization process and maintained high computation accuracy for optimizing the DNAPL-contaminated aquifer remediation strategy.

In order to explore the effect of total ammonium nitrogen (TAN) on mesophilic and thermophilic anaerobic digestion of chicken manure, the performances of anaerobic digestion of chicken manure under mesophilic and thermophilic conditions were compared through 265 days' experiment with the increased TAN when the feed total solid (TS) increased from 5% to 7.5% and 10%. During the operation, the specific methanogenic activity (SMA) test was carried out with sodium acetate. The TAN in the mesophilic and thermophilic reactors increased from 2.1~2.5to 6.1~6.5g/L when TS increased from 5% to 10%. The SMAs of the mesophilic and thermophilic reactors reduced by 44% and 100%, respectively, resulting in a decrease in the ability of the fermentation system to produce methane by acetic acid. In the mesophilic reactor, the methane yield reduced from 253 to 203 mL/gTS, associated with the accumulation of volatile fatty acids (VFAs) from 0.4 to 7.6g/L. The methane yield decreased from 181to 18mL/gTS when the VFA increased from 0.4 to 26.1g/L in the thermophilic reactor. The effect of TAN on reducing methane yield was more obvious under thermophilic condition.

The effects and mechanism of dewatered sludge bio-drying from citric acid production were studied by preheating sludge ranged from 15℃ to 30℃ in winter. Water content of preheating sludge to 20℃ decreased from initial 70% to the final 34.80% after 14d period of bio-drying. The highest temperature reached 57℃ and the period of high temperature remained 5.5d. Compared to the removal rates of bound water between 44.39% and 49.35% in other preheating groups, the group of preheating to 20℃ had much higher rate with 65.58%. It was indicated from the analysis of energy balance that the group of preheating to 25℃ had the maximum bio-energy while 82.62% of total energy was consumed on the water evaporation for the group of preheating to 20℃ with the highest energy utilization efficiency. Through the analysis of protein and polysaccharide in sludge extracellular polymer, the ratios of protein and polysaccharide in LB-EPS and TB-EPS had significant positive correlations with sludge bound water. And the contents of protein in Slime-EPS、LB-EPS、EP-EPS reduced significantly. It suggested that the decomposition of protein should be the main mechanism of heat generating and sludge dewatering for the citric acid dewatered sludge bio-drying.

The mixtures of pine sawdust/PVC plastic/bitumite were used for producing high physical properties briquettes fuel with stable intensity and high durability, which can make fully use of abandoned pine sawdust, refractory PVC plastic and low quality Qujing bituminous coal. The air dried mixtures of pine sawdust/PVC/bituminous coal were slected to make briquettes fuel under 150℃ and different pressure. The effects of material ratio and pressure on briquettes initial density, relaxed density and durability were studied. Two or three ingredients of molding fuels had higher density stability and durability than those of single material. The density stability and durability increased with the increase of pressure, but the increasing trend was slow after 15MPa. Considering that the energy consumption increases with the increase of pressure, 15MPa could be determined as the best molding pressure. 1.408g/cm³ was the most stable density of briquettes fuel at 1:1:3, while the durability reached peak value of 99.99% at 1:1:2, under condition of 15MPa.

Natural chitosan was used as raw material to prepare magnetic chitosan by cross linking with glutaraldehyde and Fe₃O₄for enhancement of the sludge dewatering. The effects of magnetic chitosan dosage, sludge pH and conditioning time on the performance of magnetic chitosan for sludge dewatering were investigated, and the enhancement mechanism was discussed. Subsequently, response surface methodology (RSM) was employed to optimize the process of sludge dewatering by the complex of CPAM and magnetic chitosan. When sludge pH value was 6.8, after conditioned by 20mg/L of magnetic chitosan for 30min, SRF and MC were decreased from 13.8×10¹²m/kg and 98.7% of the original sludge to 4.8×10¹²m/kg and 75.5%, respectively, indicated that the sludge dewatering was significantly enhanced. SRF and MC were settled as the target responses in the experiments designed by RSM, as the determination coefficients (R²) of 0.98and 0.95, the two quadratic models could agree with experimental data well. The optimal conditions for sludge dewatering were magnetic chitosan dosage of 18mg/L, CPAM dosage of 26mg/L, and conditioning time of 27 min, under this optimal condition, SRF and MC appeared as 3.3×10¹²m/kg and 59.5%, respectively, better than the individual using of the magnetic chitosan or CPAM in sludge dewatering.

It is a major bottleneck as efficient energy recovery from waste activated sludge (WAS) often require long treatment time during traditional anaerobic fermentation. In order to further enhance the resource utilization efficiency and shorten the treatment time, bio-eletrolysis, i.e., microbial electrolysis cells (MECs), assisted with free nitrous acid (FNA) was employed for WAS treatment in this study. The performance of current and hydrogen generation during bio-eletrolysis from FNA-treated WAS was compared with that obtained from un-pretreated sludge. FNA significantly boosted the hydrolysis and acidification of WAS in MECs, in detail, the concentrations of soluble carbohydrates, proteins and volatile fatty acids (VFAs) were much higher than that of un-pretreated sludge. The utilization efficiency of VFAs was higher than 97% in the MEC-FNA test with the increase of current (1.9mA) and hydrogen yield (0.86mL/g VSS), which were 3.8 and 5.1 folds higher than that in the control. What's more, pyrosequencing revealed that the abundance of anaerobic fermentation bacteria, electrochemically active bacteria and nitrate-reducing bacteria were notably enhanced.

To explore the impacts of variables on receptor model results in source apportionment for soil pollutants, the sampling data set of soil heavy metals in the middle and upper reaches of Le'an River was used as the input data set for the typical receptor model (PMF model). After obtaining the results of basic scenarios by PMF model, local sensitivity analysis method was introduced to study the sensitivity of variables on PMF diagnosis and source identification. The six-factor scenario was the best result for the simulation of PMF base model, Cu、Mo、Na₂O、As、Mn and Cd in the soil were the sensitive variables and also the main loading elements in each factor profile (i.e. the typical pollutants of each source). There was a significant difference on the sensitivity for these variables:the total sensitivity of Cu and Mo are much higher than that of the other variables, reaching 12.1 and 8.2 respectively. Therefore, it revealed that the sensitive variables should be the specific pollutants when applying the receptor model for source apportionment, and the data quality was an important factors affecting of the reliability of source apportionment.

Concentrations of 10 priority metals were compiled for eight major river basins in China. In addition, toxicology data of metals were collected and validated. The overlapping area and joint probability curve methods were adopted to characterize ecological risk and results were compared to current water quality standards. Copper and zinc were identified as the elements exhibiting the greatest potential to cause adverse effects to aquatic organisms. Current water quality criteria might not be sufficiently protective of aquatic organisms. Conversely, the water quality standards for mercury and nickel were deemed sufficient or even slightly over-protective of aquatic organisms. The ecological risks of selenium, arsenic and antimony were relatively low. Water quality standards were moderately protective for these three elements. It is suggested that current water quality standards should be revised and monitoring should be strengthened in order to provide effective protection for the aquatic ecosystem safety in China.

Thirteen kinds of perfluoroalkyl and polyfluoroalkyl substances (PFASs) were analyzed in water and sediment samples collected from Minjiang River by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). PFASs in water phase were in the range of 1.54~30.2ng/L, with mean value of (11.2±8.0) ng/L, and the greatest value appeared at the down stream of Leshan city (30.2ng/L). In addition, perfluorobutanoic acid (PFBA) was the predominant PFASs in water phase, with the concentrations of 0.16~28.4ng/L and concentration profile of 54.0%~94.1% (except Dujiang yian). PFAS concentrations in sediment displayed the highest level (47.5ng/g dw) at Yibin city, near the confluence of Minjiang River, Jinsha River and Yangtze River, while the lowest one was at Dujiang Yan (0.334ng/g dw). Furthermore, the main PFASs in sediment were perfluorohexanoate (PFHxA) (4.44%~66.9%) and perfluroroocantanoic acid (PFOA) (1.52%~77.5%). Estimated flux of PFASs in Minjiang River was 1.443tons/year, and PFBA displayed the greatest mass loading (1.037tons/year), accounting for 71.9% of total flux.

In order to investigate the effect of cascade reservoir construction on the distribution of nitrogen forms in sediments, the ion exchangeable nitrogen (IEF-N), the weak acid extractable nitrogen (WAEF-N), the strong alkaline extractable nitrogen (SAEF-N) and the strong oxidant extractable nitrogen (SOEF-N) of sediments were obtained by the sequential extraction method, and were compared to study the distribution characteristics of nitrogen forms in the sediments of Lancang River with cascade reservoir construction and Nujiang River with no hydropower station in the main stream. The main influencing factors of convertible nitrogen were analyzed. The results showed that there were differences in the occurrence environment of sediments between the two basins, and the physical and chemical properties of sediments were obviously different, and the content and spatial distribution of converted nitrogen in sediments were also different. The content of transformed nitrogen in the sediments of Lancang River were greater than that of Nujiang River, and the spatial variation of Lancang River were also greater than that of Nujiang River. The contents of IEF-N, WAEF-N, SAEF-N and SOEF-N in Nujiang River were 1.56~2.55mg/kg and 16.91~46.42mg/kg, respectively. The contents of IEF-N, WAEF-N, SAEF-N and SOEF-N in Lancang River were 1.55~14.35mg/kg, 20.77~83.08mg/kg, 1.36~92.15mg/kg and 562.61~1404.82mg/kg, respectively, and the contents of Lanchang River were 1.55~14.35mg/kg, 1.36~92.15mg/kg, 562.61~1404.82mg/kg, 20.77~8.08mg/kg, 1.36~92.15mg/kg and 562.61~1404.82mg/kg, respectively. The order of convertible nitrogen content between the two rivers were the same, which were SOEF-N>WAEF-N>SAEF-N>IEF-N, Nujiang River and the upper reached of Lancang River. The content and spatial distribution of convertible nitrogen were basically the same, but on the cascade reservoir section of Lancang River, The spatial distribution characteristics of four kinds of converted nitrogen have changed obviously. The main reason for this phenomenon was that the construction of reservoir leads to the change of physical and chemical properties of sediments, total organic carbon and particle size. The effect of redox potential on convertible nitrogen were different.

Driven by the MODIS data, DPeRS (Diffuse pollution estimation with remote sensing, DPeRS)model was used to analyses the spatial characteristic of nitrogen and phosphorus diffuse pollution in Haihe River basin on pixel scale in 2016. In Watershed Water Pollution Control Planning of the 13th Five-Year Plan published by MEE, PRC (Ministry Ecology and Environment of People's Republic China), 172 control units were defined. Here the priority control units (PCU) in Haihe River Basin were analyzed. In 2016, the total discharge of total nitrogen (TN) was 2.53×10⁴ ton with the total production being 13.62×10⁴ ton, the total phosphorus (TP) was 1597 ton with the total production being 8152 ton. The nitrogen and phosphorus diffuse pollution was relatively serious in the central and southern areas of Haihe River Basin, and the max amount of production and discharge of pollutants were appeared in Hebei province. Agriculture was the most important source for nitrogen and phosphorus diffuse pollution, followed by urban runoff. The numbers of PCU to TN and TP were 127 and 131 respectively, which covered the areas of Haihe River Basin 84.3% and 87.0% respectively.

Field observations and sediment samples collection were conducted at Lijin Hydrological Station during the Water-Sediment Regulation Scheme (WSRS) period from June 29 to July 20 in 2015 and Xiaolangdi Reservoir. The temporal variations, sources and influence by WSRS of the particulate trace metal lead (Pb) concentrations and its stable isotopic composition in the Yellow River were studied. The results showed that the contents of Pb in the suspended sediments from the Yellow River were ranged from 18.09 to 28.35μg/g, with average of 21.64μg/g, while the value of the stable isotope ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb were ranged 0.8367~0.8481, 2.0839~2.0997, respectively. Both the concentrations of Pb and its stable isotope composition were higher in the early and final stages of WSRS, but lower in the middle of this period. Pb in the studied sediments was mainly natural sources, but the content of Pb in sediments of Xiaolangdi Reservoir were significantly higher, which affected by the pollution of human activities in the middle and upper reaches of the Yellow River basin. The process of WSRS has a significant impact on the variations and source of Pb from the Yellow River into the sea. In the early and final stages of WSRS, with the lower water and sediment flux, the flooding effect on the downstream riverbed was weak, so the Pb content and isotopic composition were higher, which were mainly come from the middle and upper reaches and affected by human activities. In the main period of WSRS, the suspended sediment from Yellow River to the sea was dominated by the source of the flooding to downstream riverbed, so Pb in sediments was dominated by natural sources and was not affected by human activities.

In order to explore the signs and mechanisms of the algal blooms in the river where the backwater of the Xiangxi River are weak. Based on field data during the high-period, such as temperature, conductivity, Chl-a and the flow rate, the Xiangxi River backflow phenomenon basically ended at XX05(XiaKou Town), so the study was conducted at XX06-XX09; the algal blooms happened in July, Chl-a was above 100μg/L, and different kinds of algal blooms on XX05-XX06 and XX07-XX09; in the study area, the water temperature stratification was not obvious. The theory that water temperature stratification was the main cause of blooms was not very suitable for this water area. The study of conductivity showed that there was a significant inflection point in the vertical direction, and the inflection point depth was between the critical layer and the light compensation layer, and had a significant negative correlation with the distribution of chlorophyll a content. The average values of total nitrogen (TN) and total phosphorus (TP) in Xiangxi River were 1.849mg/L and 0.157mg/L, which exceeded the criterion of the eutrophication. The nitrogen and phosphorus content had no significant correlation with Chl-a. Other ions except N and P nutrients played an important role in the algal blooms. After the algal blooms, the conductivity gradually recovered lower from the surface to the bottom vertically, and had obvious response with the bloom and regression of algal blooms.

The functional classification of phytoplankton assemblages in western area of Yangcheng Lake and the influencing factors were explored based upon their community composition structure analysis and by using the redundancy analysis and multiple regression methods. Samples were collected monthly from March 2015 to February 2016 from 12 sites distributed in western area of Yangcheng Lake, and the phytoplankton and environmental variables were investigated. A total of 21 phytoplankton functional groups were identified as A、B、D、E、F、G、H1、J、Lo、M、MP、P、S1、T、TD、W1、W2、X1、X2、X3 and Y. And they were dominated by the 10groups of B、D、E、G、J、Lo、S1、X1、X2 and Y. The western water of Yangcheng Lake was a shallow medium-eutrophic water body with less disturbance and high mixing degree. Meanwhile, the dominant functional groups of phytoplankton in western area of Yangcheng Lake followed the seasonal succession pattern, that was B+X2+Y+X1+J+D in spring, B+X2+Y+X1+J+G+S1+Lo+E in summer, B+X2+Y+Lo+E in autumn and B+X2+Y+X1+D in winter. As well, the distribution of these functional groups in west area of Yangcheng Lake was closely related to the environmental variables. Water temperature, pH, DO, ammonia, and turbidity were the main influencing factors.

The CO₂ and CH₄ emission fluxes in the Zoigê Plateau Marsh were monitored by using the dark static chamber and Fast Greenhouse Gas Analyzer at three typical sampling sites (natural marsh, drainage marshes in the 1990s and 1970s) from May to October in 2014. The results showed that the drainage increased the soil temperature (5, 20 and 45cm depth) and reduced the water level. The ecosystem CO₂ emission fluxes of the drained marshes in 1990s[(680±329) mg CO₂/(m²·h)] and 1970s[(973±234) mg CO₂/(m²·h)] were 200% and 330% higher than that in the natural marsh. While, the ecosystem CH₄ emission fluxes of the drained marshes in 1990s[(0.78±0.52) mg CH₄/(m²·h)] and 1970s[(-0.01±0.02) mg CH₄/(m²·h)] were 90% and 100% lower than that in the natural marsh, respectively. Taking into consideration of both CO₂ and CH₄ emission fluxes, the ecosystem carbon (C) emission fluxes of the drained marshes in 1990s[(186±89) mg C/(m²·h)] and 1970s[(265±64) mg C/(m²·h)] were 180% and 300% higher than that in the natural marsh. Besides, there was a significant positive correlation between the ecosystem CO₂ emission fluxes and the soil temperature of 5cm depth in the three typical sampling sites. Whereas, there was an obvious negative correlation between the ecosystem CO₂ emission flux and the water level in the 1990s drained marsh. In addition, the ecosystem CH₄ emission flux in the natural marsh was notably positively correlated with the soil temperatures at 5, 20 and 45cm depth. However, the ecosystem CH₄ emission flux in the 1970s drained marsh was remarkably negatively correlated with the soil temperatures at 20 and 45cm depth. Meanwhile, we also found that there was a significant positive relation between the ecosystem CH₄ emission flux in the 1990s drained marsh and the water level. This research suggested that the marsh drainage could significantly increase the ecosystem C emission flux from the soil into the atmosphere in the Zoigê Plateau Marsh, subsequently decrease the soil C sink function, and further enhance the regional climate warming.

Recently, a novel multicellular filamentous microbe named as cable bacteria was observed in sediments, which belong to Desulfobulbaceae of proteobacteria. Cable bacteria conducedted complete redox reaction by coupling oxygen reduction on sediment surface with sulfide oxidation in deep anoxic layer through long-distance electron transport. Cable bacteria had three connection modes and surface ridge structure for electronic transport. It existed widely in natural environment rich in sulfate and seasonal periodic variation. This new multicellular cooperation mode had a significant impact on the biogeochemical cycle of sediments, which promoted the dissolution of iron and manganese in sulphide areas of sediments, and inhibited the release of sulfur and phosphorus. Moreover, cable bacteria was involved in the degradation of sulfide and hydrocarbon pollutants, and providing a new research direction in the field of bioremediation of contaminated sediments. Here, the discovery, physiological metabolism, habitat environmental conditions and biogeochemical cycle of cable bacteria were reviewed systematically.

Microplastics, as a novel type of plastic contaminant, widely exist in the global marine environment, and have become a hot environmental issue in the international community. Poorly managed waste is an important source of marine pollution. In this paper, the pollution situation of plastic waste and microplastics in the world and the sources of micro-plastics are briefly analyzed. And the latest progress in the revision of annexes to plastic waste covered by the Basel Convention was discussed. Meanwhile, the size, abundance, distribution and sources of microplastics in coastal, estuary and inland waters of China were summarized and analyzed. It was proposed that the management system of plastics and microplastics in China should be established and improved in the future, research and supervision on the discharge of plastics and microplastics from key industries into the ocean should be strengthened, a risk assessment system for the impact of microplastics on marine ecosystems should be established, publicity and education should be strengthened, and actively participate in the negotiations on the implementation of international environmental conventions to promote global governance.

To explore the intrusion processes of the density current and its influences on water quality in rainfall events, water temperature, dissolved oxygen, turbidity and related contaminants were monitored in June 2015 and October 2017. 11 monitoring sections were set along the upstream to main basin in Jinpen Reservoir (JPR). The underflow plunged into reservoir undergoes three stages when the inflow was 300~400m³/s:whole-section intrusion with greater water velocity, bottom intrusion with high density and mid-intrusion due to sedimentation of slit. The underflow caused the loss of thermal stability of water column, while the dissolved oxygen in the middle and lower water column were supplemented. Quantities of slit with underflow containing organic matters, nutrients and inorganic substances were transformed into reservoir and the concentration of total nitrogen, total phosphorus, turbidity and other index were resultantly increased in water column. For example, in June 2015, TN, TP, COD_Mn and turbidity were increased from 1.60, 0.021, 3.70mg/L and 5NTU to 2.37, 0.100, 5.80mg/L and 93NTU, respectively.

The influences of liquid-solid ratio, leaching time, acid rain pH, PO₄^3-, CO₃^2-, Ca²⁺ and humic acid concentration on the release of different species of uranium from uranium tailings in a uranium tailings repository were investigated by using the orthogonal tests, sequential extraction and principal component analysis. The degree of the influence of these factors on the release of the easily mobile species of uranium was in the order Ca²⁺ > acid rain pH > CO₃^2- > humic acid > leaching time > PO₄^3- > liquid-solid ratio, the first four factors were the main ones, and there was the strongest correlation between CO₃^2- and acid rain pH. The degree of the influence of these factors on the release of the potential migration species of uranium was in the order Ca²⁺ > liquid-solid ratio > leaching time > CO₃^2- > humic acid > acid rain pH>PO₄^3-, the first four factors were the main ones, and there was the strongest correlation between PO₄^3- and acid rain pH; and that the degree of the influence of these factors on the release of the stable species of uranium was in the order PO₄^3- > humic acid>CO₃^2- > acid rain pH > liquid-solid ratio>Ca²⁺ > leaching time, the first four factors were the main ones, and there was the strongest correlation between PO₄^3- and CO₃^2-.

Using the multilocus sequence typing (MLST) based on seven housekeeping loci (ftsZ, glnA, gltX, gyrB, pgi, recA and tpi), twenty Microcystis strain isolated from Lake Poyang, the largest freshwater Lake in China, were examined to study their genetic diversity and phylogenetic relationship. The MLST revealed the 20 unique sequence types (STs) for these 20 Microcystis strains and their higher genetic diversity with H value as 0.986. The phylogenetic analysis based on the seven gene sequences showed that Microcystis strains were divided into five different groups, Phylogenetic tree based on the STs from our research and Japanese lakes revealed that our STs formed the independent branch, indicating that microcysts from different areas is relatively stable. So it can be clearly characterized by MLST.

The secretion of pyocyanin (Pyo) is one of the most significant characteristics of Pseudomonas aeruginosa NY3. Previous experiments have observed that Pyo secretion is often positively correlated with hydrocarbon degradation efficiency, but its role in pollutant degradation has not been concerned, and the mechanism is unclear. Based on the coexistence of glutaric acid as a high-secreting Pyo system and reagent-grade Pyo standard, the effects of Pyo on intracellular redox enzyme activity, specific enzyme activity and extracellular electron transfer rate during hydrocarbon degradation by NY3 bacteria were studied. Glutaric acid could significantly increase the secretion of Pyo, which was 86.6% higher than that of non-glutaric acid system, and with the increase of Pyo secretion, the removal rate of hexadecane by NY3 bacteria increased by 16.29%. Pyo secretion by NY3 bacteria was beneficial to increase the activity of intracellular alkane oxidase. When the bacteria grew to 72h and the dosage of Pyo was 200L and 300L, respectively, compared with that without Pyo system, alkane was removed by NY3 bacteria. The specific activity of hydrocarbon oxidase increased by 121.8% and 346.5% respectively. At the same time, in the presence of Pyo, the extracellular electron transfer rate was increased by nearly 7 times, which increased the degradation rate of hexadecane. Based on this, we propose that Pyo secretion by NY3 bacteria can promote the degradation of hexadecane by increasing the activity of intracellular enzymes and the rate of extracellular electron transfer.

For researching the isolation distance of landfill with virus as isolation target, a modeling method based on system health risk objective was proposed to determine the influence of groundwater gradient, hydraulic conductivity and aeration zone thickness on isolation distance. Based on linear dose-effect model and acceptable infection risk [<10^-4/(person·a)], the concentration limit of enterovirus in drinking water was deduced. An analytical model of pollutant leakage-migration-degradation was constructed by coupling the leakage source strength model with the vertical migration and transformation model of water flow and virus in the aeration zone and the horizontal migration and transformation model in the aquifer. The uncertainty of parameters in the analytical model was characterized by Monte-Carlo simulation, and then a typical domestic waste landfill site was selected for case study. The result indicated that the isolation distance in sand aquifer is 44~564m, in gravel aquifer was 91m~2.39km and in coarse gravel aquifer was 1.74~27.29km. Groundwater gradient changed from 0.001 to 0.05, resulting in the isolation distance at the highest gradient was 10~20 times larger than that at the lowest gradient. When the thickness of aeration zone increases from 1 to 10m, the isolation distance could be shortened to less than 10m. The research indicated that the determination of isolation distance should be based on specific safety requirements and hydrogeological conditions.

The active sampling technique was adopted to investigate the concentration levels, profiles and spatial temporal distribution as well as the source apportionments of atmospheric PAHs in PM_2.5, PM_1.0 and gas phase. The inhalation exposure risk of local population to atmospheric PAHs was evaluated based on atmospheric observation data in Ningdong Base. The ranges of atmospheric concentration levels of ∑₁₆PAHs for PM_2.5, PM_1.0 and gas phase were 17.95~325.12ng/m³, 12.66~311.96ng/m³ and 26.33~97.88ng/m³ respectively, and the average annual concentrations were (99.42±117.48)ng/m³, (78.88±100.58)ng/m³ and (57.89±47.39)ng/m³, respectively. The spatial distributions of atmospheric PAHs levels for PM_2.5, PM_1.0 and gas phase in Baofeng site were significantly higher than that in Yinglite site for both winter and summer. The seasonal pollution characteristics indicated that ∑₁₆PAHs concentration levels were significantly higher in Baofeng site than that in Yinglite site not only in winter but in summer. Comparison of atmospheric PAHs levels in Ningdong Base with that of other cities or regions worldwide, which exhibited higher concentration levels, suggesting atmospheric PAHs pollution was more serious in Ningdong Base. Source apportionment indicated that the main emission sources of PAHs in Ningdong Base were industrial coal combustion and motor vehicle exhaust in summer, while industrial coal combustion and biomass burning in winter. The average excess inhalation cancer risks (ECR) due to human exposure to atmospheric PAHs were about 33~2628 cases per million people in Ningdong Base in winter, while 11~834 cases per million people in summer.

Based on input-output model and input-output table of China, we studied the distribution of embodied resource consumption of China's heavy chemical industry by sectors and final demand types, and the contribution of five socioeconomic drivers to resource consumption of China's heavy chemical industry. Results quantitatively confirmed that more than 75% of resource consumption of China's heavy chemical industry was embodied in the final products of construction industry and other manufacturing industries, more than 55% was embodied in the final products that formed capital in 2012. Resource intensity contributed to the decrease of fossil energy and limestone consumption of China's heavy chemical industry by -108% and -265% from 2002 to 2012, but drove the increase of iron ore consumption by +152%. Production structure contributed to the increase of fossil energy and limestone consumption of China's heavy chemical industry by +39% and +237%. Final demand level per capita contributed to the increase of all the three kinds of resource's consumption of China's heavy chemical industry by +247%, +460% and +291%.

The urban agglomerations of southern Hebei were selected as the study area. Statistical and spatial analysis methods were applied to a variety of datasets including VⅡRS thermal anomaly products from 2012~2016, industrial energy consumption, industrial exhaust emissions and air quality data. The variation law of radiation intensity of thermal anomaly was the main principle examined with the data on industrial energy consumption and pollution emissions. The fire radiative power of thermal anomalies can characterize industrial energy consumption and indirectly reflect industrial production scale and pollution emission levels. The greater the fire radiative power, the larger the scale of industrial production. Radiation intensity was highly correlated with industrial SO₂ emissions and moderately linear with NO_x emissions. The grey correlations between pollutant's concentration and industrial energy consumption, pollutant concentration and thermal anomaly radiation intensity were both higher. Among the pollutants produced by industrial production activities, particulate matter had the highest contribution to atmospheric pollution, followed by SO₂. In the 2012~2016 period, the spatial distribution of industrial production in Handan, Shijiazhuang and Langfang showed a trend toward shrinking year by year. The industrial production of Baoding and Cangzhou showed a trend of migration to the south and west.

The ratio of treated domestic sewage was used to evaluate the sewage treatment level in China. However, due to the current situation of incomplete sewer networks and rain sewage mixed flow in drainage system, clean water from raining or river flowed into wastewater treatment plant together with wastewater, therefore, herein sewage treatment ratio was referred to the amount of how much wastewater was treated, but not the amount of treated pollutant. A new indicator was used to evaluate the domestic sewage treatment status in a southwestern city of China based on pollutant treated. The concentration of concerned pollutants in influent to wastewater treatment plants (WWTP) was generally low and also fluctuated with seasons, which indicating the dilution by rainwater, river water or groundwater during the raining season. Thus, the influent data of WWTP in dry seasons was considered more suitable for the real concentration of regional domestic sewage. The sewage in our study basin was 100% treated if the traditional indicator of sewage treatment was applied. But in fact, the treatment ratios of COD_Cr, NH₃-N and TP in the whole basin were 37.50%, 36.25% and 30.14%, respectively, based on our new evaluation method. It meant more than half of the pollutants were discharged directly into the environment, which was consistent with the water quality characteristics and incomplete sewer network of the basin. In conclusion, pollutant treatment ratio is a better and more effective indicator to evaluate the level of regional sewage collection and treatment in area where the sewer network are not widespread.