The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale re...The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale reduced the total runoff volume by 50.4%through exfiltration and evapotranspiration.The wet swale significantly decreased the influent pollutant concentrations,and the effluent mean concentrations of total suspended solids,total phosphorus,chemical oxygen demand,ammonium,oxidized nitrogen,and total nitrogen in the effluent were 31 mg/L,0.10 mg/L,29 mg/L,0.52 mg/L,0.35 mg/L and1.28 mg/L,respectively.Pollutant loads were also substantially reduced from 70%to 85%.Plant uptake played an important role in nutrient removal in the wet swale.Approximately half of the nitrogen(53.8%)and phosphorus(51.5%)that entered the wet swale was incorporated in above-ground plants.It is shown that wet swales are useful for managing runoff from roads in areas of poor soil permeability.展开更多
In this study, nanoscale zero-valent iron （NZVI） were immobilized within a chelating resin （DOW 3N）. To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loadin...In this study, nanoscale zero-valent iron （NZVI） were immobilized within a chelating resin （DOW 3N）. To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe（III） solution in 0, 30 and 70% （v/v） ethanol aqueous, respectively; the bromate was used as a model contami- nant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant （Kobs） were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency ofbromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI- R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions NO3, PO43- and HCO3- were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.展开更多
基金Project(2011ZX07303-002) supported by National Water Pollution Control and Management Technology Major Projects,China
文摘The ability of a wet swale,constructed in an area of poor soil permeability,to manage runoff from a roadway was monitored through 27 storm events over a period of 8 months.During the monitoring period,the wet swale reduced the total runoff volume by 50.4%through exfiltration and evapotranspiration.The wet swale significantly decreased the influent pollutant concentrations,and the effluent mean concentrations of total suspended solids,total phosphorus,chemical oxygen demand,ammonium,oxidized nitrogen,and total nitrogen in the effluent were 31 mg/L,0.10 mg/L,29 mg/L,0.52 mg/L,0.35 mg/L and1.28 mg/L,respectively.Pollutant loads were also substantially reduced from 70%to 85%.Plant uptake played an important role in nutrient removal in the wet swale.Approximately half of the nitrogen(53.8%)and phosphorus(51.5%)that entered the wet swale was incorporated in above-ground plants.It is shown that wet swales are useful for managing runoff from roads in areas of poor soil permeability.
文摘In this study, nanoscale zero-valent iron （NZVI） were immobilized within a chelating resin （DOW 3N）. To investigate the effect of Fe loading on NZVI reactivity, three NZVI-resin composites with different Fe loading were obtained by preparing Fe（III） solution in 0, 30 and 70% （v/v） ethanol aqueous, respectively; the bromate was used as a model contami- nant. TEM reveals that increasing the Fe loading resulted in much larger size and poor dispersion of nanoscale iron particles. The results indicated that the removal efficiency of bromate and the rate constant （Kobs） were decreased with increasing the Fe loading. For the NZVI-resin composite with lower Fe loading, the removal efficiency ofbromate declined more significantly with the increase of DO concentrations. Under acidic conditions, decreasing the pH value had the most significant influence on NZVI- R3 with highest Fe loading for bromate removal; however, under alkaline conditions, the most significant influence of pH was on NZVI-R1 with lowest Fe loading. The effects of co-existing anions NO3, PO43- and HCO3- were also investigated. All of the co-existing anions showed the inhibition to bromate reduction.
