简介：Thelowremovaleffciencyoftotalnitrogen(TN)isoneofthemaindisadvantagesoftraditionalsinglestagesubsurfaceinfiltrationsystem,whichcombinesananaerobictankandasoilfilterfield.Inthisstudy,afull-scale,two-stageanaerobictankandsoiltrenchsystemwasdesignedandoperatedtoevaluatethefeasibilityandperformancesintreatingsewagefromaschoolcampusforoveraone-yearmonitoringperiod.Therawsewagewaspreparedandfedintothefirstanaerobictankandsecondtankby60%and40%,respectively.Thisnovelprocesscoulddecreasechemicaloxygendemandwiththedichromatemethodby89%-96%,suspendedsolidsby91%-97%,andtotalphosphorusby91%-97%.Thedenitrificationwassatisfactoryinthesecondstagesoiltrench,sotheremovalsofTNaswellasammonianitrogen(NH+4-N)reached68%-75%and96%-99%,respectively.ItappearedthattheremovaleffciencyofTNinthistwo-stageanaerobictankandsoiltrenchsystemwasmoreeffectivethanthatinthesinglestagesoilinfiltrationsystem.Theeffuentmetthedischargestandardforthesewagetreatmentplant(GB18918-2002)ofChina.