Cov dej qias neeg (khoom pov tseg) tso tawm los ntawm qhov chaw muaj kuab paug, vim tias muaj ntau npaum li cas los yog cov pa phem concentration, tsis ua raws li cov kev cai ntawm cov qauv tso tawm lossis tsis ua raws li cov kev cai ntawm ib puag ncig muaj peev xwm, yog li txo cov dej ib puag ncig zoo thiab cov hom phiaj ua haujlwm. , nws yuav tsum tau ua kom zoo dua qub.Hauv cov txheej txheem dej phwj tuaj, cov ntsuas uas yuav tsum tau saib xyuas suav nrog ammonia nitrogen, tag nrho phosphorus, tag nrho nitrogen, COD, pH, yaj oxygen, thiab biochemical oxygen xav tau.