To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemi...To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.展开更多
The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environment...The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.展开更多
Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking wa...Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.展开更多
Phosphorus has been closely associated with eutrophication, a growing ecological problem globally. Because bacterial and algae responds to organic and inorganic nutrients differently, developing an accurate analytical...Phosphorus has been closely associated with eutrophication, a growing ecological problem globally. Because bacterial and algae responds to organic and inorganic nutrients differently, developing an accurate analytical method for the determination of dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) is critical for understanding eutrophication. This paper describes analytical variations observed in laboratory experiments for the determination of DIP and DOP. Several experimental parameters including phosphorus reagents’ temperature, water sample matrix, pH, and autoclave methods are investigated. With the optimization of the autoclave procedure, the recoveries of 8 model organic phosphorus compounds (i.e. adenosine-5-triphosphate di-sodium salt (ATP), phytic acid (PTA), sodium tripolyphosphate (STP), methyltriphenylphosphonium bromide (MPT), p-nitrophenyl phosphate magnesium salt (p-NPP), β-D-glucose-6-phosphate monosodium salt (G-6-P) and cocarboxylase (COCA)) are all well above 90% indicating significant analytical method improvement.展开更多
Persistent organochlorine compounds, including hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polychlorinated biphenyls （PCBs） were analyzed in surface water and sediments from Balyan...Persistent organochlorine compounds, including hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polychlorinated biphenyls （PCBs） were analyzed in surface water and sediments from Balyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs （sum of α-HCH, β-HCH, y-HCH and 6-HCH） and DDTs （sum of DDT, DDD and DDE）, the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients （logK∝） for OCPs varied between 3.20 and 5.53, and for PCBs, logK∝ values ranged from 3.19 to 5.57. The observed logK∝ was lower than their equilibrium logK∝ predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.展开更多
To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） an...To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） and Ti-doped ^-Bi203 （NTB）） on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H202 improved the SMX photodegradation. TiO2 nanoparticles had a dual effect on pbotodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways： hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.展开更多
The removal of four dissolved organic matter(DOM) fractions, non-acid hydrophobics,hydrophobic acids, hydrophilics and transphilics, was achieved by coagulation-UV/H_2O_2 oxidation in post-pharmaceutical wastewater(Ph...The removal of four dissolved organic matter(DOM) fractions, non-acid hydrophobics,hydrophobic acids, hydrophilics and transphilics, was achieved by coagulation-UV/H_2O_2 oxidation in post-pharmaceutical wastewater(PhW W). Coagulation with Polyferric chloride(PFC), Polymeric ferric sulfate(PFS) and Polymeric aluminum ferric chloride(PAFC) was studied separately to evaluate the effects of the initial pH and coagulant dosage. The coagulation-UV/H_2O_2 oxidation method resulted in much higher reduction rates for dissolved organic carbon(DOC)(by 75%) and UV_(254)(by 92%) than coagulation or UV/H_2O_2 oxidation alone. The proportion of non-acid hydrophobics, hydrophobic acids, transphilics and hydrophilics removed by coagulation was 54%, 49%, 27% and 12 %, while the combined treatment removed 92%, 87%,70% and 39%, respectively. Parallel factor analysis(PARAFAC) of fluorescence measurements revealed that the humic-like fluorescent component C4 showed the highest removal(by 44%)during the coagulation stage. After coagulation-UV/H_2O_2 treatment, the humic-like fluorescent component C3 had the highest removal(by 72%), whereas xenobiotic organic fluorescent components C1 and C4 remained recalcitrant to decomposition. Significant correlations(R2> 0.8)between C1 and the hydrophobic acids and non-acid hydrophobics suggested the possibility of using fluorescence spectroscopy as an effective tool to assess variations in DOM fraction treatment efficacy in coagulation-UV/H_2O_2 systems. After the combined treatment, toxic inhibition of cellular activity by post PhW W decreased from 88% to 47% and biodegradability increased from 0.1 to 0.52.展开更多
Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis （reed） ...Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis （reed） by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m2. This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.展开更多
There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With...There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With changes of socio-economic factors as well as the geophysical conditions, there are dramatic changes on the spatial patterns of forest area. In this sense, it is of great significance to shed light on the dynamics of forest area changes to find the underlining reasons for shaping the changing patterns of forest area in Northeast China. To explore the dynamics of forest area change in Northeast China, an econometric model is developed which is composed of three equations identifying forestry production, conversion from open forest to closed forest and conversion from other land uses to closed forest so as to explore the impacts on the forest area changes from demographic, social, economic, location and geophysical factors. On this basis, we employ the Dynamics of Land System （DLS） model to simulate land-use conversions between forest area and non-forest cover and the land-use conversions within the sub-classes of forest area for the period 2000-2020 under business as usual scenario, environmental protection scenario and economic growth scenario. The simulation results show that forest area will expand continuously and there exist various kinds of changing patterns for the sub-classes of forest area, for example, closed forest will expand continuously and open forest and shrub will decrease a little bit, while area of other forest will keep intact. The research results provide meaningful decision-making information for conserving and exploiting the forest resources and makJng out the planning for forestry production Jn the Northeast China region.展开更多
A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using elect...A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using electrotopological state indices （ESI） and partial least squares （PLS） regression. The cross validated 2 Qcum and the correlation coefficient R for the model were determined to be 0.845 and 0.954, respectively. The satisfactory Q2cum and R values indicated significantly high robustness and good predictive ability for the model. The model was tested and found acceptable for the prediction of logkd （the logarithm of the deputation rate constants） by validation set. According to the model, an increase in the values of Saasc, S5＇, S4, S5 and S4＇, led to increased logkd, and a decrease in the values of Na, S2, and S6 also resulted in increased logkd. Among these descriptors, Ncl, S aasC, S5＇,, S4 and S5 made significant contributions to the value of logkd. These significant descriptors showed that the depuration of PCBs in Elliptio complanata may be mainly attributed to an equilibrium partitioning process among compartments with different lipid contents, while the reactivity of PCBs with enzymes or other molecules may play a subordinate role.展开更多
Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Wat...Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment（SPS） samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.展开更多
Highly efficient regeneration of natural zeolite was developed in conjunction with the removal of high concentrations of ammonia and potassium from the reverse osmosis effluent of anaerobic-digested wastewater by fixe...Highly efficient regeneration of natural zeolite was developed in conjunction with the removal of high concentrations of ammonia and potassium from the reverse osmosis effluent of anaerobic-digested wastewater by fixed-bed ion exchange.The elution and uptake behavior of ammonium and potassium in the fixed bed were studied.Both batch desorption tests and on-column regeneration were conducted to develop an optimum regeneration condition compatible with the wastewater requirements.The effectiveness of ammonium elution increased with increasing alkaline concentration.The increase of salt dose significantly enhanced the ammonium maximum in the elution solution.Complete ammonium elution was achieved in 6 bed volumes（BV） when the alkaline and salt concentrations were respectively 0.1 mol/L and 18.6 g/L at a flow rate of 2.5-3.0 BV/hr.Due to the higher affinity of potassium with natural clinoptilolite,complete potassium elution was not achieved in all cases.展开更多
Urban sediments have rapidly increased in recent years around the world,and their effective management has become an important problem.To remove heavy metals from stormwater runoff and use sediments as a resource,a no...Urban sediments have rapidly increased in recent years around the world,and their effective management has become an important problem.To remove heavy metals from stormwater runoff and use sediments as a resource,a novel ceramsite was developed using sewer pipe sediments(SPS),river bed sediments(RBS),urban water supply treatment sludge(WSTS),and wastewater treatment plant excess sludge(WWTS).The optimal composition was determined based on the Brunauer–Emmett–Teller specific surface area and an orthogonal test design.The adsorption characteristics of the novel ceramsite for dissolved heavy metals(Cu^(2+)and Cd^(2+)) were investigated through adsorption isotherms and kinetic experiments at(25±1)℃.Both Cu^(2+) and Cd^(2+) were effectively removed by the novel ceramsite,and their equilibrium adsorption was 4.96 mg·g^(-1) and 3.84 mg·g^(-1),respectively.Langmuir isotherms and a pseudo-first-order kinetic equation described the adsorption process better than other techniques.Characterization analysis of the ceramsite composition before and after heavy metal adsorption showed that the Cu^(2+) and Cd^(2+) contents in the ceramsite increased after adsorption.The results revealed that adsorption is both a physical and chemical process,and that ceramsite can be used as a bioretention medium to remove heavy metals from stormwater runoff while simultaneously converting problematic urban sediments into a resource.展开更多
Many studies have been conducted on environmental flow(e-flow)assessment and supply,but e-flow shortages remain common in many urban rivers.In addition to known reasons such as ever-increasing competition among water ...Many studies have been conducted on environmental flow(e-flow)assessment and supply,but e-flow shortages remain common in many urban rivers.In addition to known reasons such as ever-increasing competition among water users and inadequate execution of designed e-flow supply plans,we propose that designing weir heights without explicitly considering e-flows is another major cause of this problem.In this paper,we suggest that the measures for satisfying e-flows be extended from the water supply stage to the river channel design stage.We establish a new weir height determination framework that would more effectively satisfy the required e-flows.The new framework differs from previous frameworks,in which flood control and water retention are the major concerns and the flow during floods is set as the inflow.In the new framework,e-flow provision and flow velocity maintenance are added concerns and the actual flows for e-flow supply are set as the inflow.As a case study of the new framework’s effectiveness,we applied it to the Shiwuli River,a typical channelized urban river in Hefei,China.The old framework specified too-high weir height to meet the e-flow requirements,whereas the new framework offered more reasonable heights that improved e-flow provision.展开更多
Abstract:Hydrological regimes influence ecological patterns and processes as well as alter rates of wetland evapotranspiration.This study aimed to investigate the impact of groundwater fluctuation on evapotranspiratio...Abstract:Hydrological regimes influence ecological patterns and processes as well as alter rates of wetland evapotranspiration.This study aimed to investigate the impact of groundwater fluctuation on evapotranspiration of Phragmites australis.Supported by field data obtained from the Baiyangdian Lake in northern China,the variations in groundwater levels were explored,and the changes in soil water and evapotranspiration of reed were analyzed to investigate different groundwater level scenarios using HYDRUS-1D model.The results showed that soil water content,recharged by groundwater,remained stable in the lower soil layer but varied strongly in the upper layer of the soil profile;in comparison to evaporation,Phragmites australis transpiration contributed significantly more to the overall evapotranspiration rate;the high levels of evapotranspiration could be maintained when groundwater levels vary between 1.0 m and 1.8 m,while it was reduced with an increase in groundwater levels as a result of water stress conditions.The results also indicated that the evapotranspiration of Phragmites australis could maintain higher evapotranspiration rates under natural water levels.The evapotranspiration,in other words,might be the main water consumer,but it nevertheless has little effect on water levels during water shortages.The evapotranspiration of Phragmites australis responded to the changes in groundwater levels could help researchers understand water requirements of the wetlands and establish suitable water levels for the wetlands.展开更多
Mining,smelting and tailing deposition activities can cause metal(loid)contamination in surrounding soils,threatening ecosystems and human health.Microbial indicators are sensitive to environmental factors and have a ...Mining,smelting and tailing deposition activities can cause metal(loid)contamination in surrounding soils,threatening ecosystems and human health.Microbial indicators are sensitive to environmental factors and have a crucial role in soil ecological risk assessment.Xikuangshan,the largest active antimony(Sb)mine in the world,was taken as the research area.The soil properties,metal(loid)contents and microbial characteristics were investigated and their internal response relationships were explored by multivariate statistical analysis.The assessment of the single pollution index and Nemerow synthetic pollution index(PN)showed that the soils were mainly polluted by Sb,followed by Cd and As,in which sampling site S1 had a slight metal(loid)pollution and the other sampling sites suffered from severe synthetic metal(loid)pollution.The microbial characteristics were dissimilar among sampling points at different locations from the mining area according to hierarchical cluster analysis.The correlation analysis indicated that fluorescein diacetate hydrolase,acid phosphatase,soil basal respiration andmicrobial biomass carbonwere negatively correlatedwith PN,indicating their sensitivity to combined metal(loid)contamination;that dehydrogenase was positively correlated with pH;and that urease,potential ammonia oxidation and abundance of ammonia-oxidizing bacteria and archaea were correlated with N(nitrogen)contents.However,β-glucosidase activity had no significant correlations with physicochemical properties and metal(loid)contents.Principal components analysis suggested bioavailable Sb and pH were the dominant factors of soil environment in Xikuangshan Sb mining area.Our results can provide a theoretical basis for ecological risk assessment of contaminated soil.展开更多
Integrated urban water management （IUWM） is a useful tool that can be used to alleviate water resource shortages in developing regions like Macao, where 98% of the raw water comes from China's Mainland. In Macao...Integrated urban water management （IUWM） is a useful tool that can be used to alleviate water resource shortages in developing regions like Macao, where 98% of the raw water comes from China's Mainland. In Macao, scarce water resources deteriorate rapidly in emergency situations, such as accidental chemical spills upstream of the supply reservoir or salty tides. During these times, only the water from the two freshwater reservoirs in Macao can be used. In this study, we developed urban water management optimization models that integrated the raw water supply from the two reservoirs with various proposed governmental policies （wastewater reuse, rainwater collection, and water saving）. We then determined how various water resource strategies would influence the urban water supply in Macao in emergency situations. Our results showed that, without imported raw water, the water supply from only the two Macao reservoirs would last for 7.95 days. However, when all the government policies were included in the model, the supply could be extended to 13.79 days. Out of the three non-conventional water resources, wastewater reuse is the most beneficial for increasing the Macao water supply, and rainwater collection also has great potential.展开更多
Assessing environmental flows （e-flows） for urban rivers is important for water resources planning and river protection, Many e-flow assessment methods have been established based on species＇ habitat pro- vision re...Assessing environmental flows （e-flows） for urban rivers is important for water resources planning and river protection, Many e-flow assessment methods have been established based on species＇ habitat pro- vision requirements and pollutant dilution requirements, To avoid flood risk, however, many urban rivers have been transformed into straight, trapezoidal-profiled concrete channels, leading to the disappearance of valuable species, With the construction of water pollution-control projects, pollutant inputs into rivers have been effectively controlled in some urban rivers, For these rivers, the e-flows determined by tradi- tional methods will be very small, and will consequently lead to a low priority being given to river pro- tection in future water resources allocation and management, To more effectively assess the e-flows of channelized urban rivers, we propose three e-flow degrees, according to longitudinal hydrological con- nectivity （high, medium, and low）, in addition to the pollutant dilution water requirement determined by the mass-balance equation, In the high connectivity scenario, the intent is for the e-flows to maintain flow velocity, which can ensure the self-purification of rivers and reduce algal blooms; in the medium connectivity scenario, the intent is for the e-flows to permanently maintain the longitudinal hydrological connectivity of rivers that are isolated into several ponds by means of weirs, in order to ensure the exchange of material, energy, and information in rivers; and in the low connectivity scenario, the intent is for the e-flows to intermittently connect isolated ponds every few days （which is designed to further reduce e-flows）, The proposed methods have been used in Shiwuli River, China, to demonstrate their effectiveness, The new methods can offer more precise and realistic e-flow results and can effectively direct the construction and management of e-flow supply projects,展开更多
Aerobic granules, pre-cultivated at the organic loading rate （OLR） of 3.0 kg COD/（m3 ·day）, were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/（m3 &...Aerobic granules, pre-cultivated at the organic loading rate （OLR） of 3.0 kg COD/（m3 ·day）, were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/（m3 ·day）, respectively. Reactor performance, evolution of granule morphology, structure and microbial community at low OLRs under long-term operation （130 days） were investigated. Results showed that low OLRs did not cause significant damage to granule structure as a dominant granule morphology with size over 540 μm was maintained throughout the operation. Aerobic granules at sizes of about 750 μm were finally obtained at the low OLRs. The granule reactors operated at low OLRs demonstrated effective COD and ammonia removals （above 90%）, smaller granule sizes and less biomass. The contents of extracellular polymeric substances in the granules were decreased while the ratios of exopolysaccharide/exoprotein were increased （above 1.0）. The granules cultivated at the low OLRs showed a smoother surface and more compact structure than the seeded granules. A significant shift in microbial community was observed but the microbial diversity remained relatively stable. Confocal Laser Scanning Microscopy observation showed that the live cells were spread throughout the whole granule, while the dead cells were mainly concentrated in the outer layer of the granule, and the proteins, polysaccharides and lipids were mainly located in the central regime of the granule. In conclusion, granules cultivated at high OLRs show potential for treating low-strength organic wastewater steadily under long-term operation.展开更多
Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by ...Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by the chemical conditions in the receiving water bodies. In this review, we summarized that the aggregation of GO in aquatic environments is mostly dependent on properties of nanoparticles(size,structure, and functional groups) and complex water chemistry(p H, temperature, light, ionic strength,and dissolved organic matter). The knowledge about the aggregation/stability of GO is still insufficient due to the variations in GO properties and complex system of natural waters. Although studies about environmental transformation of graphene-related materials can be accessed but a systematic study taking into consideration the various factors of GO and aquatic systems responsible for aggregation of GO is still lacking. Therefore, we summarized that GO homoaggregation or heteroaggregation with other solid particles can affect the distribution in different depths of rivers and toxicity toward plankton or benthic organisms. More studies are needed to investigate the stability of GO in the long term, the effect of other nanomaterial on GO aggregation, the alteration of water constituents at different regions/time and its effect on GO aggregation, to understand the transportation and impact of GO in the environment.展开更多
基金supported by the National Natural Science Foundation of China(No.41905108)the National Research Program for Key Issues in Air Pollution Control(No.DQ GG0532).
文摘To study the volatile organic compounds(VOCs)emission characteristics of industrial enterprises in China,6 typical chemical industries in Yuncheng City were selected as research objects,including the modern coal chemical industry(MCC),pharmaceutical industry(PM),pesticide industry(PE),coking industry(CO)and organic chemical industry(OC).The chemical composition of 91 VOCs was quantitatively analyzed.The results showed that the emission concentration of VOCs in the chemical industry ranged from 1.16 to 155.59 mg/m^(3).Alkanes were the main emission components of MCC(62.0%),PE(55.1%),and OC(58.5%).Alkenes(46.5%)were important components of PM,followed by alkanes(23.8%)and oxygenated volatile organic compounds(OVOCs)(21.2%).Halocarbons(8.6%-71.1%),OVOCs(9.7%-37.6%)and alkanes(11.2%-27.0%)were characteristic components of CO.The largest contributor to OFP was alkenes(0.6%-81.7%),followed by alkanes(9.3%-45.9%),and the lowest onewas alkyne(0%-0.5%).Aromatics(66.9%-85.4%)were the largest contributing components to SOA generation,followed by alkanes(2.6%-28.5%),and the lowest one was alkenes(0%-4.1%).Ethylene and BTEX were the key active species in various chemical industries.The human health risk assessment showed workers long-term exposed to the air in the chemical industrial zone had a high cancer and non-cancer risk during work,and BTEX and dichloromethane were the largest contributors.
基金supported by the National Natural Science Foundation of China(52100093,52270128,and 52261135627)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011734 and 2021B1515120068)+2 种基金the Municipal Science and Technology Innovation Council of the Shen-zhen Government(KCXFZ20211020163556020 and SGDX20230116092359002)the Research Grants Council(17210219)the Innovation and Technology Fund(ITS/242/20FP)of the Hong Kong SAR Government。
文摘The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.
基金supported by the National Key Research and Development Program of China(No.2019YFD1100203).
文摘Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.
文摘Phosphorus has been closely associated with eutrophication, a growing ecological problem globally. Because bacterial and algae responds to organic and inorganic nutrients differently, developing an accurate analytical method for the determination of dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) is critical for understanding eutrophication. This paper describes analytical variations observed in laboratory experiments for the determination of DIP and DOP. Several experimental parameters including phosphorus reagents’ temperature, water sample matrix, pH, and autoclave methods are investigated. With the optimization of the autoclave procedure, the recoveries of 8 model organic phosphorus compounds (i.e. adenosine-5-triphosphate di-sodium salt (ATP), phytic acid (PTA), sodium tripolyphosphate (STP), methyltriphenylphosphonium bromide (MPT), p-nitrophenyl phosphate magnesium salt (p-NPP), β-D-glucose-6-phosphate monosodium salt (G-6-P) and cocarboxylase (COCA)) are all well above 90% indicating significant analytical method improvement.
基金supported by the Major State Basic Research Development Program (No. 2009CB421605)the National Natural Science Foundation of China (No. 40871218)+1 种基金the Scientific Research Foundation of Beijing Normal University (No. 2009SD-24)the National Water Pollution and Management Technology Project of China (No. 2009ZX07209-008)
文摘Persistent organochlorine compounds, including hexachlorocyclohexanes （HCHs）, dichlorodiphenyltrichloroethanes （DDTs） and polychlorinated biphenyls （PCBs） were analyzed in surface water and sediments from Balyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs （sum of α-HCH, β-HCH, y-HCH and 6-HCH） and DDTs （sum of DDT, DDD and DDE）, the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients （logK∝） for OCPs varied between 3.20 and 5.53, and for PCBs, logK∝ values ranged from 3.19 to 5.57. The observed logK∝ was lower than their equilibrium logK∝ predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.
基金supported by the National Basic Research Program (973) of China (No. 2010CB429003)the National Natural Science Foundation of China (No.21077010)the Fok Ying-Tong Education Foundation,China (No. 121077)
文摘To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） and Ti-doped ^-Bi203 （NTB）） on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H202 improved the SMX photodegradation. TiO2 nanoparticles had a dual effect on pbotodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways： hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.
基金supported by the National Key Scientific and Technological Project for Water Pollution Control and Management (Nos.2012ZX07202-005,2012ZX07202-002,2014 ZX07216001-2)
文摘The removal of four dissolved organic matter(DOM) fractions, non-acid hydrophobics,hydrophobic acids, hydrophilics and transphilics, was achieved by coagulation-UV/H_2O_2 oxidation in post-pharmaceutical wastewater(PhW W). Coagulation with Polyferric chloride(PFC), Polymeric ferric sulfate(PFS) and Polymeric aluminum ferric chloride(PAFC) was studied separately to evaluate the effects of the initial pH and coagulant dosage. The coagulation-UV/H_2O_2 oxidation method resulted in much higher reduction rates for dissolved organic carbon(DOC)(by 75%) and UV_(254)(by 92%) than coagulation or UV/H_2O_2 oxidation alone. The proportion of non-acid hydrophobics, hydrophobic acids, transphilics and hydrophilics removed by coagulation was 54%, 49%, 27% and 12 %, while the combined treatment removed 92%, 87%,70% and 39%, respectively. Parallel factor analysis(PARAFAC) of fluorescence measurements revealed that the humic-like fluorescent component C4 showed the highest removal(by 44%)during the coagulation stage. After coagulation-UV/H_2O_2 treatment, the humic-like fluorescent component C3 had the highest removal(by 72%), whereas xenobiotic organic fluorescent components C1 and C4 remained recalcitrant to decomposition. Significant correlations(R2> 0.8)between C1 and the hydrophobic acids and non-acid hydrophobics suggested the possibility of using fluorescence spectroscopy as an effective tool to assess variations in DOM fraction treatment efficacy in coagulation-UV/H_2O_2 systems. After the combined treatment, toxic inhibition of cellular activity by post PhW W decreased from 88% to 47% and biodegradability increased from 0.1 to 0.52.
基金supported by the Major State Basic Research Development Program (No.2010CB951104)the Program for New Century Excellent Talents in University (No. NCET-09-0233)the National Water Pollution Control and Treatment Project in China (No.2008ZX07209-009)
文摘Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis （reed） by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m2. This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.
文摘There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With changes of socio-economic factors as well as the geophysical conditions, there are dramatic changes on the spatial patterns of forest area. In this sense, it is of great significance to shed light on the dynamics of forest area changes to find the underlining reasons for shaping the changing patterns of forest area in Northeast China. To explore the dynamics of forest area change in Northeast China, an econometric model is developed which is composed of three equations identifying forestry production, conversion from open forest to closed forest and conversion from other land uses to closed forest so as to explore the impacts on the forest area changes from demographic, social, economic, location and geophysical factors. On this basis, we employ the Dynamics of Land System （DLS） model to simulate land-use conversions between forest area and non-forest cover and the land-use conversions within the sub-classes of forest area for the period 2000-2020 under business as usual scenario, environmental protection scenario and economic growth scenario. The simulation results show that forest area will expand continuously and there exist various kinds of changing patterns for the sub-classes of forest area, for example, closed forest will expand continuously and open forest and shrub will decrease a little bit, while area of other forest will keep intact. The research results provide meaningful decision-making information for conserving and exploiting the forest resources and makJng out the planning for forestry production Jn the Northeast China region.
基金supported by the Major State Basic Research Development Program(No. 2009CB421605)the National Natural Science Foundation of China(No.40871218)+1 种基金the Special Fund of State Key Laboratory(No.08ESPCT-Y)the Program for New Century Excellent Talents in Universities
文摘A quantitative structure-activity relationship （QSAR） model on depuration rate constants （ka） of polychlorinated biphenyls （PCBs） in freshwater mussel Elliptio complanata was successfully constructed using electrotopological state indices （ESI） and partial least squares （PLS） regression. The cross validated 2 Qcum and the correlation coefficient R for the model were determined to be 0.845 and 0.954, respectively. The satisfactory Q2cum and R values indicated significantly high robustness and good predictive ability for the model. The model was tested and found acceptable for the prediction of logkd （the logarithm of the deputation rate constants） by validation set. According to the model, an increase in the values of Saasc, S5＇, S4, S5 and S4＇, led to increased logkd, and a decrease in the values of Na, S2, and S6 also resulted in increased logkd. Among these descriptors, Ncl, S aasC, S5＇,, S4 and S5 made significant contributions to the value of logkd. These significant descriptors showed that the depuration of PCBs in Elliptio complanata may be mainly attributed to an equilibrium partitioning process among compartments with different lipid contents, while the reactivity of PCBs with enzymes or other molecules may play a subordinate role.
基金supported by the National Key R&D Program of China(No.2017YFA0605001)the National Natural Science Foundation of China(No.91547207)the Fund for Innovative Research Group of the National Natural Science Foundation of China(No.51721093)
文摘Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment（SPS） samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.
基金supported by the IMUS fund provided by the bio-waste utilization group,Alberta Research Council,Canadathe Fundamental Research Funds for the Central Universities (No. 2009SD-8)
文摘Highly efficient regeneration of natural zeolite was developed in conjunction with the removal of high concentrations of ammonia and potassium from the reverse osmosis effluent of anaerobic-digested wastewater by fixed-bed ion exchange.The elution and uptake behavior of ammonium and potassium in the fixed bed were studied.Both batch desorption tests and on-column regeneration were conducted to develop an optimum regeneration condition compatible with the wastewater requirements.The effectiveness of ammonium elution increased with increasing alkaline concentration.The increase of salt dose significantly enhanced the ammonium maximum in the elution solution.Complete ammonium elution was achieved in 6 bed volumes（BV） when the alkaline and salt concentrations were respectively 0.1 mol/L and 18.6 g/L at a flow rate of 2.5-3.0 BV/hr.Due to the higher affinity of potassium with natural clinoptilolite,complete potassium elution was not achieved in all cases.
基金Supported by the Training Project of Beijing Young Talents(2114751406)the Beijing Social Science Fund(15JGB052)+1 种基金the Beijing Municipal Science and Technology Project(D161100005916004)Beijing outstanding talent project for excellent youth team(2015000026833T0000)
文摘Urban sediments have rapidly increased in recent years around the world,and their effective management has become an important problem.To remove heavy metals from stormwater runoff and use sediments as a resource,a novel ceramsite was developed using sewer pipe sediments(SPS),river bed sediments(RBS),urban water supply treatment sludge(WSTS),and wastewater treatment plant excess sludge(WWTS).The optimal composition was determined based on the Brunauer–Emmett–Teller specific surface area and an orthogonal test design.The adsorption characteristics of the novel ceramsite for dissolved heavy metals(Cu^(2+)and Cd^(2+)) were investigated through adsorption isotherms and kinetic experiments at(25±1)℃.Both Cu^(2+) and Cd^(2+) were effectively removed by the novel ceramsite,and their equilibrium adsorption was 4.96 mg·g^(-1) and 3.84 mg·g^(-1),respectively.Langmuir isotherms and a pseudo-first-order kinetic equation described the adsorption process better than other techniques.Characterization analysis of the ceramsite composition before and after heavy metal adsorption showed that the Cu^(2+) and Cd^(2+) contents in the ceramsite increased after adsorption.The results revealed that adsorption is both a physical and chemical process,and that ceramsite can be used as a bioretention medium to remove heavy metals from stormwater runoff while simultaneously converting problematic urban sediments into a resource.
基金We thank the National Key Research and Development Program of China(2017YFC0404504)the Fund for Innovative Research Group of the National Natural Science Foundation of China(51721093)the National Natural Science Foundation of China(71861137001)for their financial support.
文摘Many studies have been conducted on environmental flow(e-flow)assessment and supply,but e-flow shortages remain common in many urban rivers.In addition to known reasons such as ever-increasing competition among water users and inadequate execution of designed e-flow supply plans,we propose that designing weir heights without explicitly considering e-flows is another major cause of this problem.In this paper,we suggest that the measures for satisfying e-flows be extended from the water supply stage to the river channel design stage.We establish a new weir height determination framework that would more effectively satisfy the required e-flows.The new framework differs from previous frameworks,in which flood control and water retention are the major concerns and the flow during floods is set as the inflow.In the new framework,e-flow provision and flow velocity maintenance are added concerns and the actual flows for e-flow supply are set as the inflow.As a case study of the new framework’s effectiveness,we applied it to the Shiwuli River,a typical channelized urban river in Hefei,China.The old framework specified too-high weir height to meet the e-flow requirements,whereas the new framework offered more reasonable heights that improved e-flow provision.
基金Under the auspices of the Major State Basic Research Development Program of China(973 Program)(2010CB951104)Fundamental Research Funds for the Central Universities(2012LYB12)+1 种基金Beijing Higher Education Young Elite Teacher Project(YETP0259)special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(14L01ESPC)
文摘Abstract:Hydrological regimes influence ecological patterns and processes as well as alter rates of wetland evapotranspiration.This study aimed to investigate the impact of groundwater fluctuation on evapotranspiration of Phragmites australis.Supported by field data obtained from the Baiyangdian Lake in northern China,the variations in groundwater levels were explored,and the changes in soil water and evapotranspiration of reed were analyzed to investigate different groundwater level scenarios using HYDRUS-1D model.The results showed that soil water content,recharged by groundwater,remained stable in the lower soil layer but varied strongly in the upper layer of the soil profile;in comparison to evaporation,Phragmites australis transpiration contributed significantly more to the overall evapotranspiration rate;the high levels of evapotranspiration could be maintained when groundwater levels vary between 1.0 m and 1.8 m,while it was reduced with an increase in groundwater levels as a result of water stress conditions.The results also indicated that the evapotranspiration of Phragmites australis could maintain higher evapotranspiration rates under natural water levels.The evapotranspiration,in other words,might be the main water consumer,but it nevertheless has little effect on water levels during water shortages.The evapotranspiration of Phragmites australis responded to the changes in groundwater levels could help researchers understand water requirements of the wetlands and establish suitable water levels for the wetlands.
基金supported by the National Natural Science Foundation of China(No.42030706).
文摘Mining,smelting and tailing deposition activities can cause metal(loid)contamination in surrounding soils,threatening ecosystems and human health.Microbial indicators are sensitive to environmental factors and have a crucial role in soil ecological risk assessment.Xikuangshan,the largest active antimony(Sb)mine in the world,was taken as the research area.The soil properties,metal(loid)contents and microbial characteristics were investigated and their internal response relationships were explored by multivariate statistical analysis.The assessment of the single pollution index and Nemerow synthetic pollution index(PN)showed that the soils were mainly polluted by Sb,followed by Cd and As,in which sampling site S1 had a slight metal(loid)pollution and the other sampling sites suffered from severe synthetic metal(loid)pollution.The microbial characteristics were dissimilar among sampling points at different locations from the mining area according to hierarchical cluster analysis.The correlation analysis indicated that fluorescein diacetate hydrolase,acid phosphatase,soil basal respiration andmicrobial biomass carbonwere negatively correlatedwith PN,indicating their sensitivity to combined metal(loid)contamination;that dehydrogenase was positively correlated with pH;and that urease,potential ammonia oxidation and abundance of ammonia-oxidizing bacteria and archaea were correlated with N(nitrogen)contents.However,β-glucosidase activity had no significant correlations with physicochemical properties and metal(loid)contents.Principal components analysis suggested bioavailable Sb and pH were the dominant factors of soil environment in Xikuangshan Sb mining area.Our results can provide a theoretical basis for ecological risk assessment of contaminated soil.
基金supported by the Fundo para lo Desenvolvimento das Ciências e da Tecnologia (FDCT), under Grant No. FDCT/069/2014/A2the Research Committee of the University of Macao, under Grant No MYRG072(Y1-L2)-FST13-LIC
文摘Integrated urban water management （IUWM） is a useful tool that can be used to alleviate water resource shortages in developing regions like Macao, where 98% of the raw water comes from China's Mainland. In Macao, scarce water resources deteriorate rapidly in emergency situations, such as accidental chemical spills upstream of the supply reservoir or salty tides. During these times, only the water from the two freshwater reservoirs in Macao can be used. In this study, we developed urban water management optimization models that integrated the raw water supply from the two reservoirs with various proposed governmental policies （wastewater reuse, rainwater collection, and water saving）. We then determined how various water resource strategies would influence the urban water supply in Macao in emergency situations. Our results showed that, without imported raw water, the water supply from only the two Macao reservoirs would last for 7.95 days. However, when all the government policies were included in the model, the supply could be extended to 13.79 days. Out of the three non-conventional water resources, wastewater reuse is the most beneficial for increasing the Macao water supply, and rainwater collection also has great potential.
文摘Assessing environmental flows （e-flows） for urban rivers is important for water resources planning and river protection, Many e-flow assessment methods have been established based on species＇ habitat pro- vision requirements and pollutant dilution requirements, To avoid flood risk, however, many urban rivers have been transformed into straight, trapezoidal-profiled concrete channels, leading to the disappearance of valuable species, With the construction of water pollution-control projects, pollutant inputs into rivers have been effectively controlled in some urban rivers, For these rivers, the e-flows determined by tradi- tional methods will be very small, and will consequently lead to a low priority being given to river pro- tection in future water resources allocation and management, To more effectively assess the e-flows of channelized urban rivers, we propose three e-flow degrees, according to longitudinal hydrological con- nectivity （high, medium, and low）, in addition to the pollutant dilution water requirement determined by the mass-balance equation, In the high connectivity scenario, the intent is for the e-flows to maintain flow velocity, which can ensure the self-purification of rivers and reduce algal blooms; in the medium connectivity scenario, the intent is for the e-flows to permanently maintain the longitudinal hydrological connectivity of rivers that are isolated into several ponds by means of weirs, in order to ensure the exchange of material, energy, and information in rivers; and in the low connectivity scenario, the intent is for the e-flows to intermittently connect isolated ponds every few days （which is designed to further reduce e-flows）, The proposed methods have been used in Shiwuli River, China, to demonstrate their effectiveness, The new methods can offer more precise and realistic e-flow results and can effectively direct the construction and management of e-flow supply projects,
基金supported by the National Natural Science Foundation of China (No. 21077012, 51178049)
文摘Aerobic granules, pre-cultivated at the organic loading rate （OLR） of 3.0 kg COD/（m3 ·day）, were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/（m3 ·day）, respectively. Reactor performance, evolution of granule morphology, structure and microbial community at low OLRs under long-term operation （130 days） were investigated. Results showed that low OLRs did not cause significant damage to granule structure as a dominant granule morphology with size over 540 μm was maintained throughout the operation. Aerobic granules at sizes of about 750 μm were finally obtained at the low OLRs. The granule reactors operated at low OLRs demonstrated effective COD and ammonia removals （above 90%）, smaller granule sizes and less biomass. The contents of extracellular polymeric substances in the granules were decreased while the ratios of exopolysaccharide/exoprotein were increased （above 1.0）. The granules cultivated at the low OLRs showed a smoother surface and more compact structure than the seeded granules. A significant shift in microbial community was observed but the microbial diversity remained relatively stable. Confocal Laser Scanning Microscopy observation showed that the live cells were spread throughout the whole granule, while the dead cells were mainly concentrated in the outer layer of the granule, and the proteins, polysaccharides and lipids were mainly located in the central regime of the granule. In conclusion, granules cultivated at high OLRs show potential for treating low-strength organic wastewater steadily under long-term operation.
基金financially supported by the National Key R&D Program of China (No. 2021YFC3200401)the National Natural Science Foundation of China (Nos. 21677015, 52170024 and 22006031)the Natural Science Foundation of Hebei Province (No. B2019204315)。
文摘Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by the chemical conditions in the receiving water bodies. In this review, we summarized that the aggregation of GO in aquatic environments is mostly dependent on properties of nanoparticles(size,structure, and functional groups) and complex water chemistry(p H, temperature, light, ionic strength,and dissolved organic matter). The knowledge about the aggregation/stability of GO is still insufficient due to the variations in GO properties and complex system of natural waters. Although studies about environmental transformation of graphene-related materials can be accessed but a systematic study taking into consideration the various factors of GO and aquatic systems responsible for aggregation of GO is still lacking. Therefore, we summarized that GO homoaggregation or heteroaggregation with other solid particles can affect the distribution in different depths of rivers and toxicity toward plankton or benthic organisms. More studies are needed to investigate the stability of GO in the long term, the effect of other nanomaterial on GO aggregation, the alteration of water constituents at different regions/time and its effect on GO aggregation, to understand the transportation and impact of GO in the environment.
