电化学法去除工业垃圾渗滤液中的总磷

Removal of total phosphorus in industrial landfill leachate by electrochemical method

采用电絮凝-电化学氧化组合工艺对工业垃圾渗滤液中的总磷(TP)进行去除。首先考察了电极材质、电极间距、电解电压、电解时间、曝气时长、反应体系pH等反应条件对电絮凝TP去除效果的影响,并综合经济性得到电絮凝除磷的最佳工艺条件为:铁、铝电极,脉冲电源,电极间距1.0 cm,铁电极电解电压2.0 V,电解20 s倒极,铝电极电解电压2.5 V,电解10 s倒极,反应体系pH 7~8,电解总时间15 min,电絮凝结束后无需采用曝气辅助除磷。在此最佳条件下,TP为11~15 mg/L的渗滤液样本经电絮凝处理后残余TP降至1.0~1.3 mg/L,TP去除率可达91.7%。将电絮凝工艺同Ti/RuO_(2)-IrO_(2)电极电化学氧化工艺组合,用于处理TP为14.7 mg/L的渗滤液,处理后渗滤液残余TP为0.2 mg/L,满足工业垃圾渗滤液TP≤0.3 mg/L的直接排放标准。同时,处理后渗滤液COD及氨氮也大幅下降,表明电絮凝-电化学氧化组合工艺对渗滤液样本中氨氮、COD也具有一定的处理能力。

The total phosphorus(TP)in industrial landfill leachate was removed by the combined process of electro⁃flocculation and electrochemical oxidation.In this paper,the effects of electrode materials,electrode spacing,elec⁃trolysis voltage,electrolysis time,aeration time,pH of reaction system and other reaction conditions on the removal of TP by electro-flocculation were investigated.Additional considertion of economy,the optimum technological con⁃ditions of electro-flocculation were as follows:Iron and aluminum electrodes,pulse power supply,1.0 cm of elec⁃trode spacing,2.0 V of electrolysis voltage of iron electrodes and 20 s of electrolysis time,2.5 V of electrolysis volt⁃age of aluminum electrodes and 10 s of electrolysis time,pH of the reaction system 7-8,the total electrolysis time 15 min.There was no need to use aeration-assisted phosphorus removal after the electro-flocculation.Under the opti⁃mum condition,the residual TP in the leachate samples with TP of 11-15 mg/L was reduced to 1.0-1.3 mg/L after electroflocculation,and the TP removal rate could reach 91.7%.The electro-flocculation process was combined with the Ti/RuO_(2)-IrO_(2)electrode electrochemical oxidation process to treat the leachate with TP of 14.7 mg/L.The re⁃sidual TP in the leachate after treatment was 0.2 mg/L,which met the direct discharge standard of TP≤0.3 mg/L of industrial waste leachate.At the same time,the COD and ammonia nitrogen of the leachate also was decreased sig⁃nificantly after treatment,indicating that the combined process of electro-flocculation and electrochemical oxidation also had a certain ability to treat ammonia nitrogen and COD in the leachate samples.