利用硫酸根自由基处理剩余污泥

利用K2S2O8热活化产生具有强氧化性的硫酸根自由基破解剩余污泥,与单独加热相比,考察了处理前后污泥性质的变化。实验结果表明,随着反应时间的增加,污泥分解率呈线性上升趋势,升高温度可提高K2S2O8热活化的效率,增加污泥的破解率。当反应温度90℃、加热时间90min、每克悬浮固体(SS)中K2S2O8投加量为0.5g时,污泥分解率达16.9%;微生物胞外聚合物(EPS)被分解、胞内物质释放到液相中,使污泥上清液中SCOD由单独加热时的435mg/L增至719mg/L;融胞释放的TN、TP质量浓度比单独加热处理分别增加了46%和60%;在高温及氧化剂的作用下,部分有机氮被转化成NH4+-N,使污泥上清液中的NH4+-N质量浓度由15.0mg/L增至27.8mg/L。

Treatment of excess sludge with sulfate free radical

The disintegration of excess sludge with sulfate free radical produced by heat-activated potassium persulfate was studied.The changes of the sludge′s nature before and after the treatment were investigated.The results indicated that the sludge dissolution ratio displayed a linear decrease with the increase of reaction time.Elevated temperature can improve the efficiency of heat-activated potassium persulfate and the sludge disintegration rate.In the following operation condition,reaction temperature of 90 ℃,heating time of 90 min and the K_2S_2O_8 dosage of 0.5 g per gram SS,the sludge dissolution ratio was 16.9%.In this operation,more microbial extracellular polymeric substances(EPS) were decomposed,and more intracellular material was released to the liquid phase.The concentration of SCOD was increased to 719 mg/L,which is 435 mg/L by single heating treatment;the concentration of TN,TP was increased by 46% and 60% respectively.Part of organic nitrogen was mineralized by oxidants to NH~+_4-N,whose concentration was increased from 15.0 to 27.8 mg/L.