Advanced treated municipal wastewater is an important alternative water source for agricultural irrigation.However,the possible persistence of chemical and microbiological contaminants in these waters raise potential ...Advanced treated municipal wastewater is an important alternative water source for agricultural irrigation.However,the possible persistence of chemical and microbiological contaminants in these waters raise potential safety concerns with regard to reusing treated wastewater for food crop irrigation.Two low-cost and environmentally-friendly filter media,biochar(BC)and zero-valent iron(ZVI),have attracted great interest in terms of treating reused water.Here,we evaluated the efficacy of BC-,nanosilver-amended biochar-(Ag-BC)and ZVI-sand filters,in reducing contaminants of emerging concern(CECs),Escherichia coli(E.coli)and total bacterial diversity from wastewater effluent.Six experiments were conducted with control quartz sand and sand columns containing BC,Ag-BC,ZVI,BC with ZVI,or Ag-BC with ZVI.After filtration,Ag-BC,ZVI,BC with ZVI and Ag-BC with ZVI demonstrated more than 90%(>1 log)removal of E.coli from wastewater samples,while BC,Ag-BC,BC with ZVI and Ag-BC with ZVI also demonstrated efficient removal of tested CECs.Lower bacterial diversity was also observed after filtration;however,differences were marginally significant.In addition,significantly(p<0.05)higher bacterial diversity was observed in wastewater samples collected during warmer versus colder months.Leaching of silver ions occurred from Ag-BC columns;however,this was prevented through the addition of ZVI.In conclusion,our data suggest that the BC with ZVI and Ag-BC with ZVI sand filters,which demonstrated more than 99%removal of both CECs and E.coli without silver ion release,may be effective,low-cost options for decentralized treatment of reused wastewater.展开更多
基金United States Department of Agriculture,National Institute of Food and Agriculture(NIFA),Grant number 2016-68007-25064,awarded to the University of Maryland School of Public Health,that established CONSERVE:A Center of Excellence at the Nexus of Sustainable Water Reuse,Food and HealthSC,SP,ARS and AS were also supported by NRT-INFEWS:UMD Global STEWARDS(STEM Training at the Nexus of Energy,WAter Reuse and FooD Systems)that was awarded to the University of Maryland School of Public Health by the National Science Foundation National Research Traineeship Program,Grant number 1828910.
文摘Advanced treated municipal wastewater is an important alternative water source for agricultural irrigation.However,the possible persistence of chemical and microbiological contaminants in these waters raise potential safety concerns with regard to reusing treated wastewater for food crop irrigation.Two low-cost and environmentally-friendly filter media,biochar(BC)and zero-valent iron(ZVI),have attracted great interest in terms of treating reused water.Here,we evaluated the efficacy of BC-,nanosilver-amended biochar-(Ag-BC)and ZVI-sand filters,in reducing contaminants of emerging concern(CECs),Escherichia coli(E.coli)and total bacterial diversity from wastewater effluent.Six experiments were conducted with control quartz sand and sand columns containing BC,Ag-BC,ZVI,BC with ZVI,or Ag-BC with ZVI.After filtration,Ag-BC,ZVI,BC with ZVI and Ag-BC with ZVI demonstrated more than 90%(>1 log)removal of E.coli from wastewater samples,while BC,Ag-BC,BC with ZVI and Ag-BC with ZVI also demonstrated efficient removal of tested CECs.Lower bacterial diversity was also observed after filtration;however,differences were marginally significant.In addition,significantly(p<0.05)higher bacterial diversity was observed in wastewater samples collected during warmer versus colder months.Leaching of silver ions occurred from Ag-BC columns;however,this was prevented through the addition of ZVI.In conclusion,our data suggest that the BC with ZVI and Ag-BC with ZVI sand filters,which demonstrated more than 99%removal of both CECs and E.coli without silver ion release,may be effective,low-cost options for decentralized treatment of reused wastewater.
