Firstly,the advantages and disadvantages of constructed wetlands for treating rural domestic sewage are introduced.Secondly,the types of constructed wetland plants are introduced.Thirdly,the suitability of using medic...Firstly,the advantages and disadvantages of constructed wetlands for treating rural domestic sewage are introduced.Secondly,the types of constructed wetland plants are introduced.Thirdly,the suitability of using medicinal wetland plants to treat rural domestic sewage is analyzed.Fourthly,the principles of selecting wetland plants with medicinal value are studied.Finally,commonly used constructed wetland plants and their medicinal value are introduced.展开更多
In order to investigate the feasibility of pretreating the micro-polluted Yellow River raw water by constructed wetland, an experiment was conducted using a surface flow constructed wetland with composite plant bed. T...In order to investigate the feasibility of pretreating the micro-polluted Yellow River raw water by constructed wetland, an experiment was conducted using a surface flow constructed wetland with composite plant bed. The contamination removal efficiency and their trends in the wetland treatment system were studied under different hydraulic loading rates(HLR). The contamination removal efficiencies were compared according to the seasonal change under optimum HLR. The result shows that in the same season, under different hydraulic loadings ranging from 2 to 6 m3/(m2·d) at the same period, the best HLR is 4 m3/(m2·d) in the experimental system. The average removal rates of COD, TN, ammoniacal nitrogen(NH4+-N), and TP in the constructed wetland are 38.37%, 45.97%, 39.86% and 41.69%, respectively. According to China Standard for Surface Water Resources (GB3838-2002), mean effluent of COD, TN, NH4+-N and TP can nearly reach Grade Ⅲ, GradeⅤ, GradeⅠand GradeⅠ, respectively. Furthermore, treatment efficiency of the system in summer is obvious higher than that in other seasons. The expenditure of constructing the constructed wetland with the average treating capacity of 176 m3/d and lifetime of 20 years is 17075.00 RMB. The average disposal cost is summed up to 0.17 RMB/m3, which shows that the pretreatment of the micro-polluted Yellow River raw water by constructed wetland is feasible.展开更多
Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified whic...Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified which can take up metal and metal oxide engineered nanoparticles(ENPs).It is important to evaluate if aquatic plants exhibiting potential for metal phytoremediation can be applied to remediation of metallic ENPs.Understanding the interactions between ENPs and aquatic plants,and evaluating possible influences on metal uptake and phytoremediation processes is therefore essential.This review article will address the feasibility of green plants for treatment of ENP-affected aquatic ecosystems.Discussion will include common types of ENPs in current use;transformations of ENPs in aquatic systems;the importance of microorganisms in supporting plant growth;ENP entry into the plant;the influence of microorganisms in promoting plant uptake;and recent findings in phytoremediation of ENP-affected water,including applications to constructed wetlands.展开更多
The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and be...The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and between a bio-rack system and control system was conducted on a small-scale （500 mm length × 400 mm width × 400 mm height） to evaluate the decontamination effects of four different wetland plants.There was generally a significant difference in the removal of total nitrogen （TN）,ammonia nitrogen （NH 3-N） and total phosphorus （TP）,but no significant difference in the removal of permanganate index （COD Mn） between the bio-rack wetland and control system.Bio-rack wetland planted with Thalia dealbata had higher nutrient removal rates than wetlands planted with other species.Plant fine-root （root diameter 3 mm） biomass rather than total plant biomass was related to nutrient removal efficiency.The study suggested that the nutrient removal rates are influenced by plant species,and high fine-root biomass is an important factor in selecting highly effective wetland plants for a bio-rack system.According to the mass balance,the TN and TP removal were in the range of 61.03-73.27 g/m^2 and 4.14-5.20 g/m^2 in four bio-rack wetlands during the whole operational period.The N and P removal by plant uptake constituted 34.9%-43.81% of the mass N removal and 62.05%-74.81% of the mass P removal.The study showed that the nitrification/denitrification process and plant uptake process are major removal pathways for TN,while plant uptake is an effective removal pathway for TP.展开更多
Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is uncle...Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is unclear.Here,we investigated the distribution and bio-impacts of different ENPs(Ag NPs,TiO_(2) NPs,and CeO_(2) NPs)in plants under 5-and 60-day exposure to 1 and 50 mg/L concentrations.Results showed that ENPs appeared in the vascular bundle and mesophyll cell space,which induced the variation in antioxidase activities(e.g.,superoxide dismutase[SOD],peroxidase[POD],and catalase[CAT]activities)as well as overproduction of malondialdehyde(MDA).Additionally,Ag NPs inhibited photosynthesis rate and root activity during two exposure phases.CeO_(2) NPs had positive and negative impacts on plants in 5-and 60-day exposure,respectively.Inversely,TiO_(2) NPs enhanced photosynthesis and root activity under 60-day exposure.Finally,the contents of the C,N,and P elements in plants fluctuated in response to ENPs stress.All results have a positive correlation with the wetland performance under ENPs exposure except for TiO_(2) NPs treatment.Overall,our study systematically reveals aquatic plants'responses to ENPs and provides a reference for building ecological treatment systems to purify wastewater containing ENPs.展开更多
Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in So...Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in Southeast Asian countries.As a pioneering research in Sri Lanka,we collected 24 h composite wastewater samples at the influent and effluent of two municipal STPs for consecutive 7 days to investigate occurrence,consumption and removal efficiency of seventeen antibiotics.The STP was located in Colombo and Hikkaduwa,respectively,representing two kinds of communities(i.e.local and tourists)in Sri Lanka.The targeted antibiotics were extracted by solid-phase extraction method and detected on an Agilent HPLCMSMS(1290/6470QQQ).Results illustrated that the majority of the antibiotics can be always detected from both STPs,except for chlorotetracycine(CTC),doxycycline(DOX)and florfenicol(FF).Fluoroquinolones(FQs)were detected at highest concentrations with ciprofloxacin(CIP)being the dominant compound.Concentrations of CIP in the influent samples were in the range of 433 e6010 ng/L.The consumption of antibiotics was estimated on the basis of influent mass load and catchment population data.We found difference in consumption patterns between the two served areas.Compared to local people in Colombo,tourists in Hikkaduwa appeared to take more antibiotics during the study period with the estimated daily dose of 0.25 g per 1000 persons.Moreover,macrolides accounted for a larger portion than FQs in Hikkaduwa,with azithromycin(AZM)being the most prevalent antibacterial agent.After comparison with an official report by Medical Supplies Division of Sri Lanka,we conjected that AZM was not commonly used among local people and it was mainly introduced by foreign arrivals.As for the removal efficiency,the activated sludge system of Colombo exhibited better elimination and more stable performance than the constructed wetland process of Hikkaduwa.展开更多
基金National Natural Science Foundation of China(41263006)Science and Technology Support Project of Guizhou Province(Qiankehe Support[2020]No.4Y017).
文摘Firstly,the advantages and disadvantages of constructed wetlands for treating rural domestic sewage are introduced.Secondly,the types of constructed wetland plants are introduced.Thirdly,the suitability of using medicinal wetland plants to treat rural domestic sewage is analyzed.Fourthly,the principles of selecting wetland plants with medicinal value are studied.Finally,commonly used constructed wetland plants and their medicinal value are introduced.
基金the National High Technology Research and Development Program of China(863 Program)(Grant No.2006AA06Z303).
文摘In order to investigate the feasibility of pretreating the micro-polluted Yellow River raw water by constructed wetland, an experiment was conducted using a surface flow constructed wetland with composite plant bed. The contamination removal efficiency and their trends in the wetland treatment system were studied under different hydraulic loading rates(HLR). The contamination removal efficiencies were compared according to the seasonal change under optimum HLR. The result shows that in the same season, under different hydraulic loadings ranging from 2 to 6 m3/(m2·d) at the same period, the best HLR is 4 m3/(m2·d) in the experimental system. The average removal rates of COD, TN, ammoniacal nitrogen(NH4+-N), and TP in the constructed wetland are 38.37%, 45.97%, 39.86% and 41.69%, respectively. According to China Standard for Surface Water Resources (GB3838-2002), mean effluent of COD, TN, NH4+-N and TP can nearly reach Grade Ⅲ, GradeⅤ, GradeⅠand GradeⅠ, respectively. Furthermore, treatment efficiency of the system in summer is obvious higher than that in other seasons. The expenditure of constructing the constructed wetland with the average treating capacity of 176 m3/d and lifetime of 20 years is 17075.00 RMB. The average disposal cost is summed up to 0.17 RMB/m3, which shows that the pretreatment of the micro-polluted Yellow River raw water by constructed wetland is feasible.
基金Support from the Office of the Provost,Ball State University(USA)the University of Siena(Italy)。
文摘Certain plants have demonstrated the capability to take up and accumulate metals,thus offering the potential to remediate metal-contaminated water and sediment.Several aquatic species have further been identified which can take up metal and metal oxide engineered nanoparticles(ENPs).It is important to evaluate if aquatic plants exhibiting potential for metal phytoremediation can be applied to remediation of metallic ENPs.Understanding the interactions between ENPs and aquatic plants,and evaluating possible influences on metal uptake and phytoremediation processes is therefore essential.This review article will address the feasibility of green plants for treatment of ENP-affected aquatic ecosystems.Discussion will include common types of ENPs in current use;transformations of ENPs in aquatic systems;the importance of microorganisms in supporting plant growth;ENP entry into the plant;the influence of microorganisms in promoting plant uptake;and recent findings in phytoremediation of ENP-affected water,including applications to constructed wetlands.
基金the financial support of the National water pollution control and management technology major project (No. 2008ZX07101)
文摘The bio-rack is a new approach for treating low-concentration polluted river water in wetland systems.A comparative study of the efficiency of contaminant removal between four plant species in bio-rack wetlands and between a bio-rack system and control system was conducted on a small-scale （500 mm length × 400 mm width × 400 mm height） to evaluate the decontamination effects of four different wetland plants.There was generally a significant difference in the removal of total nitrogen （TN）,ammonia nitrogen （NH 3-N） and total phosphorus （TP）,but no significant difference in the removal of permanganate index （COD Mn） between the bio-rack wetland and control system.Bio-rack wetland planted with Thalia dealbata had higher nutrient removal rates than wetlands planted with other species.Plant fine-root （root diameter 3 mm） biomass rather than total plant biomass was related to nutrient removal efficiency.The study suggested that the nutrient removal rates are influenced by plant species,and high fine-root biomass is an important factor in selecting highly effective wetland plants for a bio-rack system.According to the mass balance,the TN and TP removal were in the range of 61.03-73.27 g/m^2 and 4.14-5.20 g/m^2 in four bio-rack wetlands during the whole operational period.The N and P removal by plant uptake constituted 34.9%-43.81% of the mass N removal and 62.05%-74.81% of the mass P removal.The study showed that the nitrification/denitrification process and plant uptake process are major removal pathways for TN,while plant uptake is an effective removal pathway for TP.
基金supported by the National Natural Science Foundation of China(Grant No.51708056)the National Major Project of Pollution Control and Treatment Science and Technology(Grant No.2017ZX07401003-4)Chongqing Talents Plan for Young Talents(No.CQY201905062)。
文摘Engineered nanoparticles(ENPs)threaten the environment through wastewater discharging.Generally,constructed wetlands(CWs)are efficient methods for ENPs removal.However,the biotoxicity of ENPs on plants in CWs is unclear.Here,we investigated the distribution and bio-impacts of different ENPs(Ag NPs,TiO_(2) NPs,and CeO_(2) NPs)in plants under 5-and 60-day exposure to 1 and 50 mg/L concentrations.Results showed that ENPs appeared in the vascular bundle and mesophyll cell space,which induced the variation in antioxidase activities(e.g.,superoxide dismutase[SOD],peroxidase[POD],and catalase[CAT]activities)as well as overproduction of malondialdehyde(MDA).Additionally,Ag NPs inhibited photosynthesis rate and root activity during two exposure phases.CeO_(2) NPs had positive and negative impacts on plants in 5-and 60-day exposure,respectively.Inversely,TiO_(2) NPs enhanced photosynthesis and root activity under 60-day exposure.Finally,the contents of the C,N,and P elements in plants fluctuated in response to ENPs stress.All results have a positive correlation with the wetland performance under ENPs exposure except for TiO_(2) NPs treatment.Overall,our study systematically reveals aquatic plants'responses to ENPs and provides a reference for building ecological treatment systems to purify wastewater containing ENPs.
基金This work was funded by the International Partnership Program of the Chinese Academy of Sciences,(Grant No.132744KYSB20170002)UCAS scholarship for international students.The authors want to acknowledge the generous support from the National Water Supply and Drainage Board(Sewerage division),Sri Lanka and to Mr.S.M.Samaraweera for the assistance in wastewater sampling.
文摘Most of the monitoring data on the occurrence of antibiotics in sewage treatment plants(STPs)have been reported from Europe,North America and some countries in Northeast Asia,while very limited data can be found in Southeast Asian countries.As a pioneering research in Sri Lanka,we collected 24 h composite wastewater samples at the influent and effluent of two municipal STPs for consecutive 7 days to investigate occurrence,consumption and removal efficiency of seventeen antibiotics.The STP was located in Colombo and Hikkaduwa,respectively,representing two kinds of communities(i.e.local and tourists)in Sri Lanka.The targeted antibiotics were extracted by solid-phase extraction method and detected on an Agilent HPLCMSMS(1290/6470QQQ).Results illustrated that the majority of the antibiotics can be always detected from both STPs,except for chlorotetracycine(CTC),doxycycline(DOX)and florfenicol(FF).Fluoroquinolones(FQs)were detected at highest concentrations with ciprofloxacin(CIP)being the dominant compound.Concentrations of CIP in the influent samples were in the range of 433 e6010 ng/L.The consumption of antibiotics was estimated on the basis of influent mass load and catchment population data.We found difference in consumption patterns between the two served areas.Compared to local people in Colombo,tourists in Hikkaduwa appeared to take more antibiotics during the study period with the estimated daily dose of 0.25 g per 1000 persons.Moreover,macrolides accounted for a larger portion than FQs in Hikkaduwa,with azithromycin(AZM)being the most prevalent antibacterial agent.After comparison with an official report by Medical Supplies Division of Sri Lanka,we conjected that AZM was not commonly used among local people and it was mainly introduced by foreign arrivals.As for the removal efficiency,the activated sludge system of Colombo exhibited better elimination and more stable performance than the constructed wetland process of Hikkaduwa.
