There is an urgent need to investigate the distinct performance and mechanism of traditional constructed wetland(CW),microbial fuel cells-constructed wetland(MFC-CW)and direct-enchanced constructed wetland(EC-CW)for a...There is an urgent need to investigate the distinct performance and mechanism of traditional constructed wetland(CW),microbial fuel cells-constructed wetland(MFC-CW)and direct-enchanced constructed wetland(EC-CW)for antibiotics removal.To address this issues,three kinds of CWs were bulit and distinct performance and mechanism for levofloxacin(LVFX)removal was expored in this study.MFC-CW,EC-CW achieved high LVFX removal efficiencies compared with traditional constructed wetland(96.0%in MFC-CW,95.0%in EC-CW and 91.2%in CW)and the biodegradation was the key contributor(90.7%-95.3%).MFC-CW is better capable to stimulate microbial activity and strengthen the removal effect of LVFX.MFC-CW performed well in reducing the effluent's ecotoxicity(dehydrogenase activity)and antibiotic resistance genes(ARGs).ARGs were mainly distributed in the anode region of MFC-CW while accumulating in the cathode region of EC-CW.Atribacteria,Chlorobi,Synergistetes and Firmicutes significicant effect on the efficiencies of TN,NH_(4)^(+),and LVFX.The core node for microbial community interaction in CW was only Pseudomonas in Proteobacteria(OTU4537).While MFC-CW included Opitutae_vadin HA64(OTU3153)in Verrucomicrobia,Desulfomicrobium(OTU3629)in Proteobacteria,and Actinobacteria Gaiellales(OTU4206),and EC-CW included Mesotoga(OTU1104)in Thermotogae,Syntrophus(OTU3207)in Proteobacteria and Emticicia(OTU3788)in Bacteroidetes.MFC-CW and EC-CW increased the abundance of critical microbial communities,and the microbial communities were more closely related.This study improved the understanding of the molecular mechanisms underlying the enhancement of CW by the two bioelectrochemical methods.展开更多
Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth...Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth operation of the process, as hydrodynamic constraints require a coarse particle size, whereas wastewater treatment recommends a fine particle size. This study investigates the suitability of laterite and shale as substrates of different sizes (1 - 3, 3 - 5 and 5 - 8 mm) in CWs for domestic wastewater treatment. The study was carried out in an experimental pilot plant consisting of 12 parallelepiped beds (C × C = 0.4 × 0.4 m2;H = 0.6 m) filled from bottom to top with 0.1 m of gravel and 0.4 m of shale or laterite of different grain sizes with two replications. During the six months of operation, plant biomass and stem diameter of Pennisetum purpureum used as vegetation in the CWs were determined. Raw and treated water were also sampled and analyzed for pollutants, including chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total Kjedahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS), using International Organization for Standardization (ISO) analytical methods. P. purpureum developed much better in the CW beds lined with shale;plant biomass ranged from 13.8 to 14.7 kg/m2 and from 11.2 to 12.5 kg/m2 in the beds lined with shale and laterite, respectively, as did stump diameter, which ranged from 15.5 to 16.1 cm and from 11.10 to 12.7 cm, respectively. However, the highest values for biomass and stump diameter for each material were obtained in the beds lined with 1 - 3 mm geomaterials. Pollutant removal efficiencies were highest in the CWs lined with laterite and shale of 1 - 3 mm grain size (76.9% - 83% COD, 78% - 84.7% BOD5, 55.5% - 72.2% TKN, 58.4% - 72.4% TP, 78.1% - 80.2% TSS), with the highest values recorded in the shale-lined beds. However, the 3 - 5 mm grain size of both materials provided quality filtrates (140 - 174 mg/L COD, 78.5 - 94.8 mg/L BOD5, 4.6 - 5.7 mg/L TP) in line with local wastewater discharge levels. This size of geomaterials appears to be suitable for optimization purposes, although further work with these materials, such as increasing the depth of the wetland, is required to improve the level of NTK and TSS discharge.展开更多
Constructed wetlands(CWs) are a promising method to treat effluent from wastewater treatment plants(WWTPs),However,low carbon/nitrogen(C/N) ratios of the influent inhibit denitrification in CWs,resulting in poor nitro...Constructed wetlands(CWs) are a promising method to treat effluent from wastewater treatment plants(WWTPs),However,low carbon/nitrogen(C/N) ratios of the influent inhibit denitrification in CWs,resulting in poor nitrogen removal efficiency.Herein,we compared traditional(control),biochar(BC), andβ-cyclodextrin-fu nctionalized biochar(BC@β-CD) CW systems to investigate nitrogen removal from influent with low C/N ratios,and the mechanisms that enhance this process.The highest nitrogen removal rates were observed in the BC@β-CD group,with rates 45.89% and 42.48% higher than those of the control,accompanied by a 70.57% and 85.45% decrease in nitrous oxide release,when the C/N ratio decreased from4 to 2,respectively.Metagenomic and enzymatic analyses indicated that BC@β-CD enhances nitrogen removal by coordinately promoting carbon metabolism and increasing denitrification enzyme activities,without affecting microbial species diversity in CWs.Structural equation modeling confirmed that the foremost advantages of BC@β-CD were effective electron generation and transportation resulting from increased activities of nicotinamide adenine dinucleotide(NADH) dehydrogenase and the electron transfer system(ETS),thereby strategically reallocating more carbon metabolic flow to support denitrification.Our results show that the application of BC@β-CD in CWs to optimize the reallocation of electrons from carbon metabolism is a feasible strategy to enhance denitrification under low C/N conditions.展开更多
Discharge from sewage treatment plants can deteriorate river water quality due to improper management or insufficient levels of treatment.To address these challenges,constructed wetland systems(CWSs)have been widely u...Discharge from sewage treatment plants can deteriorate river water quality due to improper management or insufficient levels of treatment.To address these challenges,constructed wetland systems(CWSs)have been widely used as a sustainable and effective solution for wastewater management.This study provides an overview of the conceptual design for a CWS to treat the discharge from the Papan Regional Sewage Treatment Plant(RSTP).The design influent for the CWS was determined,and the proposed sizing was based on simulation results to achieve the targeted concentrations consistent with Water Quality Index(WQI)Class II.The MUSIC-X software was used in this study to simulate pollutant removal performance,hydraulic behavior,and effluent quality under various flow conditions.The model was set up using site-specific inflow parameters,targeted effluent concentrations,and wetland configuration inputs,including surface area,depth,vegetation zones,and retention times.This study introduces an innovative approach by adopting the paddy field concept as the geometrical design of a multi-cell CWS,covering a total surface area of 1,250,000m^(2)and divided into two sections(Wetland 1 and Wetland 2),with different planting plots separated by a gabion wall.The innovation lies in reimagining abandoned mining ponds as functional wetland zones,while using a paddy field-inspired grid layout to enhance hydraulic control,pollutant removal,and land efficiency.This approach transforms degraded land into an eco-engineered,cost-effective,and scalable wastewater treatment system-a novel model for tropical developing regions.展开更多
Microbial fuel cell(MFC)coupled constructedwetland(CW)is regarded as a promising green technology due to its simultaneous removal performance for the co-occurrence of various contaminants in wastewater.In this study,t...Microbial fuel cell(MFC)coupled constructedwetland(CW)is regarded as a promising green technology due to its simultaneous removal performance for the co-occurrence of various contaminants in wastewater.In this study,the simultaneous removal performance of sulfamethazine(SMZ)and hexavalent chromium Cr(VI)in the CW and MFC-CW systems was investigated.The removal efficiencies of total nitrogen(N),total phosphorus(P),and chemical oxygen demand(COD)were also examined.The results demonstrated that Cr(VI)was effectively eliminated with an excellent removal efficiency of>98.0%,followed by SMZ with a removal efficiency of 70.3%-85.6%.Additionally,during the long-term operation period,the average removal efficiency for N,P,and COD ranged from 74.0%to 96.1%,83.6%to 94.1%,and 91.1%to 95.3%,respectively.The microbial community and antibiotic resistance genes(ARGs)in the anode and cathode were also analyzed separately to evaluate the SMZ and Cr(VI)removal performance of MFC-CW.The abundance of corresponding ARGs was slightly different in the anode and cathode regions.The average abundance of sul4 in the SMZ+Cr(VI)treatment MFC-CW was significantly higher than that of other sul1-3.This study offers valuable insights for the simultaneous removal of SMZ and Cr(VI)from wastewater by MFC-CW.展开更多
Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jar...Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.展开更多
This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside th...This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside three distinct substrate types to improve wastewater treatment efficacy. The study examines the combination of two primary treatments with different substrate types in constructed wetlands (CW1, CW2, and CW3). The primary treatments include the existing wastewater treatment plant (WWTP) in Podgorica, involving coarse material removal through screens, inert material separation in aerated sand traps, and sediment and suspended matter removal in primary sedimentation tanks. The Extreme Separator (ExSep) was employed to evaluate its efficacy as a primary treatment method. The research demonstrates that the efficiency of CW can be significantly enhanced by selecting suitable primary treatment methods and substrates in Podgorica’s conditions. The most promising results were achieved by combining ExSep as a primary treatment with secondary treatment in CW-3. The removal efficiencies after CW3 for COD, BOD, and TSS exceeded 89%, 93%, and 91%, respectively. The outcomes underscore the significance of primary treatment in mitigating pollutant loads before discharge into the constructed wetlands, emphasizing potential areas for further optimization in wastewater treatment practices to enhance environmental sustainability and water quality management.展开更多
The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aer...The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aeration(NSA)in oil-contaminated water is one of the factors that affect the persistence and metabolic functioning of hydrocarbon-degrading microorganisms.In the present investigation,the influence of the addition of NSA on the persistence of the augmented bacteria,copy of(alkane hydroxylase gene)alkB gene,and its expression level in the water,soil,and plants of CWs were evaluated.The CWs mesocosms were developed by the vegetation of Typha latifolia and Cyperus laevigatus and inoculated with the bacterial consortium(Pseudomonas putida TYRI39,Acinetobacter junii TYRH47,Acinetobacter sp.CYRH17,Pseudomonas sp.CYSI27,and Pseudomonas sp.TYRH42).The mesocosms were provided with nutrients(20 mg l−1 N,2.6 mg l−1 P,and 16.4 mg l−1 K)in liquid form,surfactant Tween-20(0.2%,v/v)in liquid form,and aeration(≥7.0±1 mg l−1 DO)using aeration pump.The addition of NSA in CWs enhanced the persistence and metabolic functioning of the inoculated bacteria in the water,rhizospheric soil,and plants.The maximum hydrocarbon removal(97%)was observed in the water treated by CWs having C.laevigatus,bacteria,and NSA,and it is correlated with the copy numbers of alkB and its expression level.The application of NSA in CWs not only improved bacterial persistence and catabolic gene expression but also increased plant development and hydrocarbon removal.展开更多
Antibiotics,their transformation products,and the translocation of antibiotic-resistant genes in the environment pose significant health risks to humans,animals,and ecosystems,aligning with the One Health concept.Cons...Antibiotics,their transformation products,and the translocation of antibiotic-resistant genes in the environment pose significant health risks to humans,animals,and ecosystems,aligning with the One Health concept.Constructed wetlands hold substantial yet underutilized potential for treating wastewater from agricultural,domestic sewage,or contaminated effluents from wastewater treatment plants,with the goal of eliminating antibiotics.However,the comprehensive understanding of the distribution,persistence,and dissipation processes of antibiotics within constructed wetlands remains largely unexplored.In this context,we provide an overview of the current application of stable isotope analysis at natural abundance to antibiotics.We explore the opportunities of an advanced multiple stable isotope approach,where isotope concepts could be effectively applied to examine the fate of antibiotics in wetlands.The development of a conceptual framework to study antibiotics in wetlands using multi-element stable isotopes introduces a new paradigm,offering enhanced insights into the identification and quantification of natural attenuation of antibiotics within wetland systems.This perspective has the potential to inspire the general public,governmental bodies,and the broader research community,fostering an emphasis on the utilization of stable isotope analysis for studying antibiotics and other emerging micropollutants in wetland systems.展开更多
The Faleme River, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m<sup>3</sup>) is affected by severe erosion because of mining activities that takes place throughout ...The Faleme River, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m<sup>3</sup>) is affected by severe erosion because of mining activities that takes place throughout the riverbed. To preserve this important watercourse and ensure the sustainability of its services, selecting and implementing appropriates restorations techniques is vital. In this context, the purpose of this paper was to present an overview of the actions and techniques that can be implemented for the restoration/rehabilitation of the Faleme. The methodological approach includes field investigation, water sampling, literature review with cases studies and SWOT analysis of the four methods presented: river dredging, constructed wetlands, floating treatment wetlands and chemical precipitation (coagulation and flocculation). The study confirmed the pollution of the river by suspended solids (TSS > 1100 mg/L) and heavy metals such as iron, zinc, aluminium, and arsenic. For the restoration methods, it was illustrated through description of their mode of operation and through some case studies presented, that all the four methods have proven their effectiveness in treating rivers but have differences in their costs, their sustainability (detrimental to living organisms or causing a second pollution) and social acceptance. They also have weaknesses and issues that must be addressed to ensure success of rehabilitation. For the case of the Faleme river, after analysis, floating treatment wetlands are highly recommended for their low cost, good removal efficiency if the vulnerability of the raft and buoyancy to strong waves and flow is under control.展开更多
We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)model.Considering the Se...We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)model.Considering the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is unavailable.The S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were obtained.The proposed approach was first verified in simulation with satisfactory results.It was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,USA.According to local observations and forest descriptions,the range of estimated tree heights was overall reasonable.Comparing the heights with the ICESat-2 tree heights at 23 sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is possible.For instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be explored.Also,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season.展开更多
In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed...In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.展开更多
A membrane-less constructed wetland microbial fuel cell （CW-MFC） is constructed and operated under continuous flow with a hydraulic retention time （HRT） of 2 d. Fed with glucose, the CW-MFC generates a stable curr...A membrane-less constructed wetland microbial fuel cell （CW-MFC） is constructed and operated under continuous flow with a hydraulic retention time （HRT） of 2 d. Fed with glucose, the CW-MFC generates a stable current density of over 2 A/m3 with a resistor of 1 kΩ and has a chemical oxygen demand （COD） removal efficiency of more than 90% after the startup of 2 to 3 d. A series of systems with the electrode spacings of 10, 20, 30 and 40 cm are compared. It is found that the container with the electrode spacing of 20 cm gains the highest voltage of 560 mV, the highest power density of 0. 149 W/m 3, and the highest Coulombic efficiency of 0.313%. It also has the highest COD removal efficiency of 94. 9%. In addition, the dissolved oxygen （DO） concentrations are observed as the lowest level in the middle of all the CW-MFC reactors. The results show that the more COD is removed, the greater power is generated, and the relatively higher Coulombic efficiency will be achieved. The present study indicates that the CW-MFC process can be used as a cost-effective and environmentally friendly wastewater treatment with simultaneous power generation.展开更多
Constructed wetlands as a wastewater eco-treatment technology has devel-oped for decades. Combining wastewater-treatment with water recycle in an efficient way, it plays an important role in water body restoration and...Constructed wetlands as a wastewater eco-treatment technology has devel-oped for decades. Combining wastewater-treatment with water recycle in an efficient way, it plays an important role in water body restoration and ecological construction. Constructed wetlands with unique advantages have attracted intensive attention since it developed, and have been widely used in treatment of domestic sewage, industrial wastewater, and mine wastewater. In this paper, we summarized the clas-sification, composition, combination, operation mode and pol utant removal mecha-nism of constructed wetlands, as wel as the research progress on the application of constructed wetland in wastewater treatment at home and abroad. In addition, in view of the problems of using constructed wetlands to treat wastewater in China, corresponding solutions were put forward, including setting up system construction standards for constructed wetlands, developing the regulatory and enhancing tech-niques of nitrogen and phosphorus removal, and taking advantage of the unique features of constructed wetlands to improve and restore ecological environment.展开更多
[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purificati...[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purification principle of pollutants were introduced,and then purification effect was analyzed through controlling nitrogen and phosphorus pollution from rice field drainage by floating plants constructed wetland.[Result] By means of floating plants constructed wetland,the average removal rate of total nitrogen(TN) from double-season early and late rice field drainage reached 52.17% and 62.23%,respectively,while that of total phosphorus(TP) was 45.69% and 74.37%,respectively,with better removal effect.Meanwhile,floating plants have ecological and ornamental value to some extent.[Conclusion] Floating plants constructed wetland could not only control nitrogen and phosphorus pollution in field drainage effectively but also keep farmland ecosystem in healthy state.展开更多
The basic chemistry laboratories of three colleges and universities in Guizhou Province were investigated completely,especially the pollution situations of the basic chemistry projects were counted,and the discharge a...The basic chemistry laboratories of three colleges and universities in Guizhou Province were investigated completely,especially the pollution situations of the basic chemistry projects were counted,and the discharge amounts of the poisonous and harmful pollutants in the waste liquid from laboratories were monitored and analyzed.On the basis of the summing-up and analysis of the current research findings,a simple and feasible treatment scheme through flocculating,precipitating and constructed wetlands was designed to control the three kinds of excessive pollutants.展开更多
In this study, the project of constructed wetland for treatment of tailwater from the wastewater treatment plant in Wudang Mountain was taken as an example, and the technological processes, pollution load, wetland bed...In this study, the project of constructed wetland for treatment of tailwater from the wastewater treatment plant in Wudang Mountain was taken as an example, and the technological processes, pollution load, wetland bed structure, bed filler, selection of plants and hydraulic conditions of the subsurface flow constructed wetland were discussed. A subsurface flow constructed wetland, which covered an area of 7 227 m^2 was finally designed. It could treat 7 000 m^3 of tailwater from the wastewater treatment plant a day. In addition, the system could reduce the emission of COD, BODs, TN, TP and NH3-N by 25.55, 25.55, 12.78, 1.28 and 17.89 t respectively a day. The outlet water was proved to reach the Standard A of the first class in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918-2002）.展开更多
[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used ...[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used as matrix,the biological grid integrated vertical flow constructed wetland system was built to strengthen treatment for black and malodorous river,and the activities of urease and phosphatase of two fillers in different functional areas of constructed wetland were tested to study the film formation property of two fillers in different functional areas.[Result]Both urease and phosphatase activities on biofilm of soft filler were significantly higher than on biofilm of honeycomb stone filler;indicating that choosing soft filler was more advantageous to the growth of biofilm;and urease activity had significant correlation with total nitrogen removal rate,while phosphatase activity had no significant correlation with total phosphorus removal rate.[Conclusion]This study provided evidences for utilizing the activities of urease and phosphatase to evaluate the purification effect of black and malodorous river and choose appropriate filler.展开更多
[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biologi...[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.展开更多
The dynamic of growth and nutrient （N and P） absorption of Coix lacryma-jobi Linn.in constructed wetland （CW）,as well as the effect of constructed wetland harvest on N,P absorption in eutrophic water were studied....The dynamic of growth and nutrient （N and P） absorption of Coix lacryma-jobi Linn.in constructed wetland （CW）,as well as the effect of constructed wetland harvest on N,P absorption in eutrophic water were studied.The results revealed that,in Summer and Autumn,especially in August,C.lacryma-jobi could obtain higher biomass and N,P accumulations,thereby achieving the most efficient purification; from the breeding value point of view,N,P contents could be improved by the appropriate increase of harvest times of C.lacryma-jobi,while too many harvest times was inappropriate to the wastewater purification by C.lacryma-jobi and the nutrients accumulation.So,C.lacryma-jobi should be harvested completely in August during its growth period,and twice-3 times of harvests was appropriate.展开更多
基金supported by the Regional Cooperation Program of Shanxi Province(No.202304041101039)ICC-CAS(No.SCJC-WRW-2023-18)+1 种基金the Fundamental Research Program of Shanxi Province(No.202203021222404)the Open Research Fund of State Environmental Protection Key Laboratory for Lake Pollution Control(No.2022HPYB-09)。
文摘There is an urgent need to investigate the distinct performance and mechanism of traditional constructed wetland(CW),microbial fuel cells-constructed wetland(MFC-CW)and direct-enchanced constructed wetland(EC-CW)for antibiotics removal.To address this issues,three kinds of CWs were bulit and distinct performance and mechanism for levofloxacin(LVFX)removal was expored in this study.MFC-CW,EC-CW achieved high LVFX removal efficiencies compared with traditional constructed wetland(96.0%in MFC-CW,95.0%in EC-CW and 91.2%in CW)and the biodegradation was the key contributor(90.7%-95.3%).MFC-CW is better capable to stimulate microbial activity and strengthen the removal effect of LVFX.MFC-CW performed well in reducing the effluent's ecotoxicity(dehydrogenase activity)and antibiotic resistance genes(ARGs).ARGs were mainly distributed in the anode region of MFC-CW while accumulating in the cathode region of EC-CW.Atribacteria,Chlorobi,Synergistetes and Firmicutes significicant effect on the efficiencies of TN,NH_(4)^(+),and LVFX.The core node for microbial community interaction in CW was only Pseudomonas in Proteobacteria(OTU4537).While MFC-CW included Opitutae_vadin HA64(OTU3153)in Verrucomicrobia,Desulfomicrobium(OTU3629)in Proteobacteria,and Actinobacteria Gaiellales(OTU4206),and EC-CW included Mesotoga(OTU1104)in Thermotogae,Syntrophus(OTU3207)in Proteobacteria and Emticicia(OTU3788)in Bacteroidetes.MFC-CW and EC-CW increased the abundance of critical microbial communities,and the microbial communities were more closely related.This study improved the understanding of the molecular mechanisms underlying the enhancement of CW by the two bioelectrochemical methods.
文摘Constructed Wetlands (CWs) are currently one of the most promising techniques for wastewater treatment, having demonstrated their effectiveness. However, the choice of substrate particle size is critical to the smooth operation of the process, as hydrodynamic constraints require a coarse particle size, whereas wastewater treatment recommends a fine particle size. This study investigates the suitability of laterite and shale as substrates of different sizes (1 - 3, 3 - 5 and 5 - 8 mm) in CWs for domestic wastewater treatment. The study was carried out in an experimental pilot plant consisting of 12 parallelepiped beds (C × C = 0.4 × 0.4 m2;H = 0.6 m) filled from bottom to top with 0.1 m of gravel and 0.4 m of shale or laterite of different grain sizes with two replications. During the six months of operation, plant biomass and stem diameter of Pennisetum purpureum used as vegetation in the CWs were determined. Raw and treated water were also sampled and analyzed for pollutants, including chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total Kjedahl nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS), using International Organization for Standardization (ISO) analytical methods. P. purpureum developed much better in the CW beds lined with shale;plant biomass ranged from 13.8 to 14.7 kg/m2 and from 11.2 to 12.5 kg/m2 in the beds lined with shale and laterite, respectively, as did stump diameter, which ranged from 15.5 to 16.1 cm and from 11.10 to 12.7 cm, respectively. However, the highest values for biomass and stump diameter for each material were obtained in the beds lined with 1 - 3 mm geomaterials. Pollutant removal efficiencies were highest in the CWs lined with laterite and shale of 1 - 3 mm grain size (76.9% - 83% COD, 78% - 84.7% BOD5, 55.5% - 72.2% TKN, 58.4% - 72.4% TP, 78.1% - 80.2% TSS), with the highest values recorded in the shale-lined beds. However, the 3 - 5 mm grain size of both materials provided quality filtrates (140 - 174 mg/L COD, 78.5 - 94.8 mg/L BOD5, 4.6 - 5.7 mg/L TP) in line with local wastewater discharge levels. This size of geomaterials appears to be suitable for optimization purposes, although further work with these materials, such as increasing the depth of the wetland, is required to improve the level of NTK and TSS discharge.
基金supported by the National Natural Science Foundation of China(52321005)the Guangdong Basic and Applied Basic Research Foundation(2023A1515012383 and 2024A1515030138)+1 种基金the State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology,2021TS30)the Shenzhen Science and Technology Program(KQTD20190929172630447 and KCXFZ20211020163404007).
文摘Constructed wetlands(CWs) are a promising method to treat effluent from wastewater treatment plants(WWTPs),However,low carbon/nitrogen(C/N) ratios of the influent inhibit denitrification in CWs,resulting in poor nitrogen removal efficiency.Herein,we compared traditional(control),biochar(BC), andβ-cyclodextrin-fu nctionalized biochar(BC@β-CD) CW systems to investigate nitrogen removal from influent with low C/N ratios,and the mechanisms that enhance this process.The highest nitrogen removal rates were observed in the BC@β-CD group,with rates 45.89% and 42.48% higher than those of the control,accompanied by a 70.57% and 85.45% decrease in nitrous oxide release,when the C/N ratio decreased from4 to 2,respectively.Metagenomic and enzymatic analyses indicated that BC@β-CD enhances nitrogen removal by coordinately promoting carbon metabolism and increasing denitrification enzyme activities,without affecting microbial species diversity in CWs.Structural equation modeling confirmed that the foremost advantages of BC@β-CD were effective electron generation and transportation resulting from increased activities of nicotinamide adenine dinucleotide(NADH) dehydrogenase and the electron transfer system(ETS),thereby strategically reallocating more carbon metabolic flow to support denitrification.Our results show that the application of BC@β-CD in CWs to optimize the reallocation of electrons from carbon metabolism is a feasible strategy to enhance denitrification under low C/N conditions.
基金Higher Institution Centre of Excellence Program(HICoE),Grant/Award Number:A305-LRAKH001-0004403901-0000。
文摘Discharge from sewage treatment plants can deteriorate river water quality due to improper management or insufficient levels of treatment.To address these challenges,constructed wetland systems(CWSs)have been widely used as a sustainable and effective solution for wastewater management.This study provides an overview of the conceptual design for a CWS to treat the discharge from the Papan Regional Sewage Treatment Plant(RSTP).The design influent for the CWS was determined,and the proposed sizing was based on simulation results to achieve the targeted concentrations consistent with Water Quality Index(WQI)Class II.The MUSIC-X software was used in this study to simulate pollutant removal performance,hydraulic behavior,and effluent quality under various flow conditions.The model was set up using site-specific inflow parameters,targeted effluent concentrations,and wetland configuration inputs,including surface area,depth,vegetation zones,and retention times.This study introduces an innovative approach by adopting the paddy field concept as the geometrical design of a multi-cell CWS,covering a total surface area of 1,250,000m^(2)and divided into two sections(Wetland 1 and Wetland 2),with different planting plots separated by a gabion wall.The innovation lies in reimagining abandoned mining ponds as functional wetland zones,while using a paddy field-inspired grid layout to enhance hydraulic control,pollutant removal,and land efficiency.This approach transforms degraded land into an eco-engineered,cost-effective,and scalable wastewater treatment system-a novel model for tropical developing regions.
基金supported by the National Natural Science Foundation of China(Nos.51968072 and 52160023)Xinjiang Science Fund for Distinguished Young Scholars(No.2021D01E15)+1 种基金the Tianshan Yingcai-Youth talent support program of Xinjiang(No.2022TSYCCX0010)the“Youth talent support program”of Xinjiang Normal University(No.XJNUQB2022-24).
文摘Microbial fuel cell(MFC)coupled constructedwetland(CW)is regarded as a promising green technology due to its simultaneous removal performance for the co-occurrence of various contaminants in wastewater.In this study,the simultaneous removal performance of sulfamethazine(SMZ)and hexavalent chromium Cr(VI)in the CW and MFC-CW systems was investigated.The removal efficiencies of total nitrogen(N),total phosphorus(P),and chemical oxygen demand(COD)were also examined.The results demonstrated that Cr(VI)was effectively eliminated with an excellent removal efficiency of>98.0%,followed by SMZ with a removal efficiency of 70.3%-85.6%.Additionally,during the long-term operation period,the average removal efficiency for N,P,and COD ranged from 74.0%to 96.1%,83.6%to 94.1%,and 91.1%to 95.3%,respectively.The microbial community and antibiotic resistance genes(ARGs)in the anode and cathode were also analyzed separately to evaluate the SMZ and Cr(VI)removal performance of MFC-CW.The abundance of corresponding ARGs was slightly different in the anode and cathode regions.The average abundance of sul4 in the SMZ+Cr(VI)treatment MFC-CW was significantly higher than that of other sul1-3.This study offers valuable insights for the simultaneous removal of SMZ and Cr(VI)from wastewater by MFC-CW.
基金support of the Yaque del Norte Water Fund(FAYN),INTEC(Grant No.CBA-330810-2020-P-1)Fondo Dominicano de Ciencia y Tecnologia(FONDOCYT)(Grant No.2022-2B2-161)。
文摘Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.
文摘This research explores strategies to enhance the efficiency of secondary treatment in Vertical Flow Constructed Wetlands (CW) in Montenegro. The focus is on selecting appropriate primary treatment methods alongside three distinct substrate types to improve wastewater treatment efficacy. The study examines the combination of two primary treatments with different substrate types in constructed wetlands (CW1, CW2, and CW3). The primary treatments include the existing wastewater treatment plant (WWTP) in Podgorica, involving coarse material removal through screens, inert material separation in aerated sand traps, and sediment and suspended matter removal in primary sedimentation tanks. The Extreme Separator (ExSep) was employed to evaluate its efficacy as a primary treatment method. The research demonstrates that the efficiency of CW can be significantly enhanced by selecting suitable primary treatment methods and substrates in Podgorica’s conditions. The most promising results were achieved by combining ExSep as a primary treatment with secondary treatment in CW-3. The removal efficiencies after CW3 for COD, BOD, and TSS exceeded 89%, 93%, and 91%, respectively. The outcomes underscore the significance of primary treatment in mitigating pollutant loads before discharge into the constructed wetlands, emphasizing potential areas for further optimization in wastewater treatment practices to enhance environmental sustainability and water quality management.
基金the Researchers Supporting Project number(RSP2024R437)King Saud University,Riyadh,Saudi ArabiaThe authors are thankful to the Higher Education Commission(HEC)for the grant of IRSIP Fellowship to the lead author for research at Aarhus University Denmark and ALP Pakistan Agriculture Research Council(PARC)grant No.NR-086.
文摘The use of constructed wetlands(CWs)is one of the best options to treat wastewater.In CWs,microorganisms play a major role in the degradation of organic pollutants but the concentration of nutrients,surfactant,and aeration(NSA)in oil-contaminated water is one of the factors that affect the persistence and metabolic functioning of hydrocarbon-degrading microorganisms.In the present investigation,the influence of the addition of NSA on the persistence of the augmented bacteria,copy of(alkane hydroxylase gene)alkB gene,and its expression level in the water,soil,and plants of CWs were evaluated.The CWs mesocosms were developed by the vegetation of Typha latifolia and Cyperus laevigatus and inoculated with the bacterial consortium(Pseudomonas putida TYRI39,Acinetobacter junii TYRH47,Acinetobacter sp.CYRH17,Pseudomonas sp.CYSI27,and Pseudomonas sp.TYRH42).The mesocosms were provided with nutrients(20 mg l−1 N,2.6 mg l−1 P,and 16.4 mg l−1 K)in liquid form,surfactant Tween-20(0.2%,v/v)in liquid form,and aeration(≥7.0±1 mg l−1 DO)using aeration pump.The addition of NSA in CWs enhanced the persistence and metabolic functioning of the inoculated bacteria in the water,rhizospheric soil,and plants.The maximum hydrocarbon removal(97%)was observed in the water treated by CWs having C.laevigatus,bacteria,and NSA,and it is correlated with the copy numbers of alkB and its expression level.The application of NSA in CWs not only improved bacterial persistence and catabolic gene expression but also increased plant development and hydrocarbon removal.
文摘Antibiotics,their transformation products,and the translocation of antibiotic-resistant genes in the environment pose significant health risks to humans,animals,and ecosystems,aligning with the One Health concept.Constructed wetlands hold substantial yet underutilized potential for treating wastewater from agricultural,domestic sewage,or contaminated effluents from wastewater treatment plants,with the goal of eliminating antibiotics.However,the comprehensive understanding of the distribution,persistence,and dissipation processes of antibiotics within constructed wetlands remains largely unexplored.In this context,we provide an overview of the current application of stable isotope analysis at natural abundance to antibiotics.We explore the opportunities of an advanced multiple stable isotope approach,where isotope concepts could be effectively applied to examine the fate of antibiotics in wetlands.The development of a conceptual framework to study antibiotics in wetlands using multi-element stable isotopes introduces a new paradigm,offering enhanced insights into the identification and quantification of natural attenuation of antibiotics within wetland systems.This perspective has the potential to inspire the general public,governmental bodies,and the broader research community,fostering an emphasis on the utilization of stable isotope analysis for studying antibiotics and other emerging micropollutants in wetland systems.
文摘The Faleme River, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m<sup>3</sup>) is affected by severe erosion because of mining activities that takes place throughout the riverbed. To preserve this important watercourse and ensure the sustainability of its services, selecting and implementing appropriates restorations techniques is vital. In this context, the purpose of this paper was to present an overview of the actions and techniques that can be implemented for the restoration/rehabilitation of the Faleme. The methodological approach includes field investigation, water sampling, literature review with cases studies and SWOT analysis of the four methods presented: river dredging, constructed wetlands, floating treatment wetlands and chemical precipitation (coagulation and flocculation). The study confirmed the pollution of the river by suspended solids (TSS > 1100 mg/L) and heavy metals such as iron, zinc, aluminium, and arsenic. For the restoration methods, it was illustrated through description of their mode of operation and through some case studies presented, that all the four methods have proven their effectiveness in treating rivers but have differences in their costs, their sustainability (detrimental to living organisms or causing a second pollution) and social acceptance. They also have weaknesses and issues that must be addressed to ensure success of rehabilitation. For the case of the Faleme river, after analysis, floating treatment wetlands are highly recommended for their low cost, good removal efficiency if the vulnerability of the raft and buoyancy to strong waves and flow is under control.
文摘We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)model.Considering the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is unavailable.The S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were obtained.The proposed approach was first verified in simulation with satisfactory results.It was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,USA.According to local observations and forest descriptions,the range of estimated tree heights was overall reasonable.Comparing the heights with the ICESat-2 tree heights at 23 sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is possible.For instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be explored.Also,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season.
文摘In Saint-Louis, Senegal, a constructed wetland with horizontal flow reed beds (FHa and FHb) has demonstrated significant efficacy in treating municipal wastewater. Analyzing various treatment stages, the system showed only a slight temperature variation, from an influent average of 26.3°C to an effluent of 24.7°C. Electrical conductivity decreased from 1331 mS/cm to 974.5 mS/cm post-primary treatment, with suspended solids (SS) dramatically reduced from 718.9 mg/L to 5.7 mg/L in the final effluent. Biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) saw a notable decrease, from initial levels of 655.6 mg/L and 1240 mg/L to 2.3 mg/L and 71.3 mg/L, respectively. Nitrogenous compounds (N-TN) and phosphates () also decreased significantly, indicating the system’s nutrient removal capacity. Microbiological analysis revealed a reduction in fecal coliforms from 7.5 Ulog/100ml to 1.8 Ulog/100ml and a complete elimination of helminth eggs. The presence of Phragmites and Typha was instrumental in enhancing these reductions. The system’s compliance with the Senegalese standards for disposal into natural environments, WHO recommendations for unrestricted water reuse in irrigation, and the European legislation for water reuse was established. The effluent quality met the stringent criteria for various classes of agricultural reuse, illustrating the system’s potential for sustainable water management. This wetland model presents a robust solution for water-stressed regions, ensuring environmental protection while supporting agricultural needs. The study calls for ongoing research to further refine the system for optimal, reliable wastewater treatment and water resource sustainability.
基金The Fundamental Research Funds for the Central Universitiesthe National Natural Science Foundation of China (No.51109038)
文摘A membrane-less constructed wetland microbial fuel cell （CW-MFC） is constructed and operated under continuous flow with a hydraulic retention time （HRT） of 2 d. Fed with glucose, the CW-MFC generates a stable current density of over 2 A/m3 with a resistor of 1 kΩ and has a chemical oxygen demand （COD） removal efficiency of more than 90% after the startup of 2 to 3 d. A series of systems with the electrode spacings of 10, 20, 30 and 40 cm are compared. It is found that the container with the electrode spacing of 20 cm gains the highest voltage of 560 mV, the highest power density of 0. 149 W/m 3, and the highest Coulombic efficiency of 0.313%. It also has the highest COD removal efficiency of 94. 9%. In addition, the dissolved oxygen （DO） concentrations are observed as the lowest level in the middle of all the CW-MFC reactors. The results show that the more COD is removed, the greater power is generated, and the relatively higher Coulombic efficiency will be achieved. The present study indicates that the CW-MFC process can be used as a cost-effective and environmentally friendly wastewater treatment with simultaneous power generation.
基金Supported by the National Key Technology R&D Program(2012BAD40B02)~~
文摘Constructed wetlands as a wastewater eco-treatment technology has devel-oped for decades. Combining wastewater-treatment with water recycle in an efficient way, it plays an important role in water body restoration and ecological construction. Constructed wetlands with unique advantages have attracted intensive attention since it developed, and have been widely used in treatment of domestic sewage, industrial wastewater, and mine wastewater. In this paper, we summarized the clas-sification, composition, combination, operation mode and pol utant removal mecha-nism of constructed wetlands, as wel as the research progress on the application of constructed wetland in wastewater treatment at home and abroad. In addition, in view of the problems of using constructed wetlands to treat wastewater in China, corresponding solutions were put forward, including setting up system construction standards for constructed wetlands, developing the regulatory and enhancing tech-niques of nitrogen and phosphorus removal, and taking advantage of the unique features of constructed wetlands to improve and restore ecological environment.
基金Supported by Natural Science Foundation of Guangxi Province(0991026)Foundation of Guangxi Key Laboratory of Environmental Engineering and Protection Assessment(0701K019)+1 种基金Project of Environmental Engineering Innovation Team of Talent Small Upland Construction in Universities in Guangxi([2007]Number71)InnovationProgram Project of Postgraduate Education in Guangxi Province(2009105960815M25)~~
文摘[Objective] The control effect of floating plants constructed wetland to nitrogen and phosphorus pollution from rice field drainage was studied.[Method] Firstly,the characteristic of floating plants and the purification principle of pollutants were introduced,and then purification effect was analyzed through controlling nitrogen and phosphorus pollution from rice field drainage by floating plants constructed wetland.[Result] By means of floating plants constructed wetland,the average removal rate of total nitrogen(TN) from double-season early and late rice field drainage reached 52.17% and 62.23%,respectively,while that of total phosphorus(TP) was 45.69% and 74.37%,respectively,with better removal effect.Meanwhile,floating plants have ecological and ornamental value to some extent.[Conclusion] Floating plants constructed wetland could not only control nitrogen and phosphorus pollution in field drainage effectively but also keep farmland ecosystem in healthy state.
基金Supported by Natural Science Foundation Projects of Education Department of Guizhou Province (2006319)
文摘The basic chemistry laboratories of three colleges and universities in Guizhou Province were investigated completely,especially the pollution situations of the basic chemistry projects were counted,and the discharge amounts of the poisonous and harmful pollutants in the waste liquid from laboratories were monitored and analyzed.On the basis of the summing-up and analysis of the current research findings,a simple and feasible treatment scheme through flocculating,precipitating and constructed wetlands was designed to control the three kinds of excessive pollutants.
文摘In this study, the project of constructed wetland for treatment of tailwater from the wastewater treatment plant in Wudang Mountain was taken as an example, and the technological processes, pollution load, wetland bed structure, bed filler, selection of plants and hydraulic conditions of the subsurface flow constructed wetland were discussed. A subsurface flow constructed wetland, which covered an area of 7 227 m^2 was finally designed. It could treat 7 000 m^3 of tailwater from the wastewater treatment plant a day. In addition, the system could reduce the emission of COD, BODs, TN, TP and NH3-N by 25.55, 25.55, 12.78, 1.28 and 17.89 t respectively a day. The outlet water was proved to reach the Standard A of the first class in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （GB 18918-2002）.
基金Supported by National Major Science and Technology Projects(2009ZX07317-006)National Major Science and Technology Projects(2009ZX07317-009)~~
文摘[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used as matrix,the biological grid integrated vertical flow constructed wetland system was built to strengthen treatment for black and malodorous river,and the activities of urease and phosphatase of two fillers in different functional areas of constructed wetland were tested to study the film formation property of two fillers in different functional areas.[Result]Both urease and phosphatase activities on biofilm of soft filler were significantly higher than on biofilm of honeycomb stone filler;indicating that choosing soft filler was more advantageous to the growth of biofilm;and urease activity had significant correlation with total nitrogen removal rate,while phosphatase activity had no significant correlation with total phosphorus removal rate.[Conclusion]This study provided evidences for utilizing the activities of urease and phosphatase to evaluate the purification effect of black and malodorous river and choose appropriate filler.
基金Supported by National Water Special Project"River Water Environment Comprehensive Management Technology Study and Comprehensive demonstration"(2008ZX07209-002-002)China Institute of Water Resources and Hydropower Research Open Fund(IWHRKF201013)~~
文摘[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia（Bl.） Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia（Bl.） Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area.
基金Supported by Project Sponsored by National Natural Science Foundation (30370146)Projects Sponsored by European Union (ERBIC18CT960059)~~
文摘The dynamic of growth and nutrient （N and P） absorption of Coix lacryma-jobi Linn.in constructed wetland （CW）,as well as the effect of constructed wetland harvest on N,P absorption in eutrophic water were studied.The results revealed that,in Summer and Autumn,especially in August,C.lacryma-jobi could obtain higher biomass and N,P accumulations,thereby achieving the most efficient purification; from the breeding value point of view,N,P contents could be improved by the appropriate increase of harvest times of C.lacryma-jobi,while too many harvest times was inappropriate to the wastewater purification by C.lacryma-jobi and the nutrients accumulation.So,C.lacryma-jobi should be harvested completely in August during its growth period,and twice-3 times of harvests was appropriate.
