组合式土壤渗滤系统处理农村厕所黑水的性能评估OA

Toilet-discharged blackwater is characterized by high dispersity and elevated pollutant concentrations.To address the environmental pollution caused by rural toilet blackwater,this study developed a soil infiltration system utilizing substrate combinations for blackwater treatment.The adsorption efficiency of single substrates for nitrogen,phosphorus,and COD(chemical oxygen demand)was first investigated.Subsequently,the pollutant removal performance of soil infiltration systems with different substrate combinations was evaluated.The optimal combination,determined as a 1:1:1 volume ratio of soil,biochar,and fly ash ceramsite,was selected for further treatment studies under varying nitrogen loads.The results demonstrated that the constructed soil infiltration system achieved average removal rates of 97.42％for NH4+-N(ammonium nitrogen),96.21％for TN(total nitrogen),84.08％for TP(total phosphorus),and 92.86％for COD.When the NH4+-N concentration in the influent ranged from 90 to 260 mg·L-1,the effluent concentration remained relatively stable,and nitrogen removal efficiency improved.Meanwhile,the concentrations of TP and COD in the effluent tended to decrease.The effluent quality from all treatment groups met or exceeded the Class III standards specified in the"Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"(GB 18918-2002).The soil infiltration system effectively reduces pollutant concentrations in rural toilet blackwater,demonstrating significant potential for improving rural environments and promoting sustainable agricultural development.