The combination method of intermittent influent and vertical flow wetlands （VFW） was used in the test to treat the domestic wastewater. Four artificial wetlands including Typha latifolia wetland,Phragmites australis...The combination method of intermittent influent and vertical flow wetlands （VFW） was used in the test to treat the domestic wastewater. Four artificial wetlands including Typha latifolia wetland,Phragmites australis （P.H.） wetland,polyculture wetlands （Typha latifolia and Phragmites australis） and non-vegetation wetland were established in the test. The effects of hydraulic retention time （HRT） and plant species on pollutants removal efficiencies were studied. The results showed that when HRT=7,the treatment efficiencies of wetlands with plants for the removal of TN and NH＋4-N were up to 99.65% and 99.58%,respectively. For the control wetland,TN removal efficiency was up to 87.9% when HRT were 6 days,and NH＋4-N removal efficiency was up to 91.8% when HRT were 5 days. TP removal efficiencies of four wetlands were higher than 93% when HRT was 6 days. Through the studies on different plants,it was found that vegetation wetlands had better nitrogen removal efficiency than non-vegetation wetland. The treatment efficacy of Phragmites australis wetland and polyculture wetland was better than Typha latifolia wetland.展开更多
This study evaluated the capability of a constructed wetland for treating saline wastewater. A pilot-scale constructed wetland system was set up and was initially operated at low, then increasing salt levels to determ...This study evaluated the capability of a constructed wetland for treating saline wastewater. A pilot-scale constructed wetland system was set up and was initially operated at low, then increasing salt levels to determine the effect of salinity on the contaminants＇ removal performance. The effect of hydraulic retention time （HRT） variation on treatment efficiency of the reed wetland was also discussed. Average removal efficiencies of the reed （Phragmites australis） wetland were found to be 79.0% for COD, 72.2% for ammonia nitrogen （NH3-N） and 82.8% for total phosphorus （TP）. Reed planting had obvious improvement on COD and NH3-N removal efficiency when compared to an unplanted system. With the seawater proportion in the influent increasing from 20% to 30%, the TP removal efficiency improved obviously. COD removal efficiency of the reed wetland was positively correlated with HRT under high salinity condition, while excess HRT had adverse impacts on the NH3-N and TP removal. Optimal HRT for NH3-N and TP removal was 4 days. Results obtained can be beneficially used to improve the use of constructed wetlands in saline wastewater treatment.展开更多
In this bench scale submerged membrane bioreactor, effect of solid retention time and hydraulic retention time on membrane fouling propensity has been studied. This experiment is carried out at different solid retenti...In this bench scale submerged membrane bioreactor, effect of solid retention time and hydraulic retention time on membrane fouling propensity has been studied. This experiment is carried out at different solid retention time of 5, 10, 30, 70 and 98 days; and fouling behavior of membrane bioreactor is investigated. Average effluent quality is found to be 88.14%-94.38%. The experiment with different hydraulic retention is carried for 3 to 4 days and fouling behavior has been investigated. The effluent quality at different hydraulic retention time of 1, 2, 3, 5, 10 and 24 hours has been investigated. This paper aims to search optimal values of solid and hydraulic retention times at which lower fouling and higher organic removal efficiency can be obtained. This study has been mainly focused on operating parameters rather than microbial structure, effect and analysis of activated sludge to membrane fouling.展开更多
基金Supported by National Natural Science Foundation of China(50908116 )211 Foundation of Nanjing Normal University(2009112XGQ0054)+1 种基金Jiang su High-funded Construction ProjectsMajor Project of Jiangsu Provincial Department of Education(2009105TSJ0165)~~
文摘The combination method of intermittent influent and vertical flow wetlands （VFW） was used in the test to treat the domestic wastewater. Four artificial wetlands including Typha latifolia wetland,Phragmites australis （P.H.） wetland,polyculture wetlands （Typha latifolia and Phragmites australis） and non-vegetation wetland were established in the test. The effects of hydraulic retention time （HRT） and plant species on pollutants removal efficiencies were studied. The results showed that when HRT=7,the treatment efficiencies of wetlands with plants for the removal of TN and NH＋4-N were up to 99.65% and 99.58%,respectively. For the control wetland,TN removal efficiency was up to 87.9% when HRT were 6 days,and NH＋4-N removal efficiency was up to 91.8% when HRT were 5 days. TP removal efficiencies of four wetlands were higher than 93% when HRT was 6 days. Through the studies on different plants,it was found that vegetation wetlands had better nitrogen removal efficiency than non-vegetation wetland. The treatment efficacy of Phragmites australis wetland and polyculture wetland was better than Typha latifolia wetland.
文摘This study evaluated the capability of a constructed wetland for treating saline wastewater. A pilot-scale constructed wetland system was set up and was initially operated at low, then increasing salt levels to determine the effect of salinity on the contaminants＇ removal performance. The effect of hydraulic retention time （HRT） variation on treatment efficiency of the reed wetland was also discussed. Average removal efficiencies of the reed （Phragmites australis） wetland were found to be 79.0% for COD, 72.2% for ammonia nitrogen （NH3-N） and 82.8% for total phosphorus （TP）. Reed planting had obvious improvement on COD and NH3-N removal efficiency when compared to an unplanted system. With the seawater proportion in the influent increasing from 20% to 30%, the TP removal efficiency improved obviously. COD removal efficiency of the reed wetland was positively correlated with HRT under high salinity condition, while excess HRT had adverse impacts on the NH3-N and TP removal. Optimal HRT for NH3-N and TP removal was 4 days. Results obtained can be beneficially used to improve the use of constructed wetlands in saline wastewater treatment.
文摘In this bench scale submerged membrane bioreactor, effect of solid retention time and hydraulic retention time on membrane fouling propensity has been studied. This experiment is carried out at different solid retention time of 5, 10, 30, 70 and 98 days; and fouling behavior of membrane bioreactor is investigated. Average effluent quality is found to be 88.14%-94.38%. The experiment with different hydraulic retention is carried for 3 to 4 days and fouling behavior has been investigated. The effluent quality at different hydraulic retention time of 1, 2, 3, 5, 10 and 24 hours has been investigated. This paper aims to search optimal values of solid and hydraulic retention times at which lower fouling and higher organic removal efficiency can be obtained. This study has been mainly focused on operating parameters rather than microbial structure, effect and analysis of activated sludge to membrane fouling.
