利用具有强氧化性质的K2S2O8试剂作为研究对象,考察了对污泥重金属Pb、Zn、Cu、Cd的去除影响、脱水表现以及处理前后污泥性质的变化.结果表明:在起始pH值为2.0,反应时间1h,温度25℃,投加1.34g/g SS的K2S2O8,可改善污泥的脱水性能.其中,滤饼含水率可由82.6%降至74.8%;污泥比阻由6.70×108S2/g下降至5.43×108S2/g.K2S2O8氧化处理污泥,可使污泥絮体快速分解,上清液COD从15.2mg/L增至187.0mg/L;TN从6.03mg/L增至22.7mg/L;TP则由8.15mg/L变为12.7mg/L;污泥TSS相应降低了9.4%.污泥重金属去除率随着投加量的增加而增加,当K2S2O8投加量达到2.01g/g SS时,污泥重金属Pb、Zn、Cu、Cd去除率可分别达到63.90%、87.10%、86.40%以及84.25%.当投加量大于2.01g/g SS,各重金属去除率趋于稳定.低pH值能够提高污泥中重金属的去除率.K2S2O8与污泥反应后,污泥重金属转移到上清液中,对上清液投加0.075%的CaO,pH值提高,可以相应去除上清液中16.95%的Pb、54.70%的Zn、58.90%的Cu以及21.95%的Cd,TN和TP含量也明显降低.%The objectives of the study were to investigate the effects of the strong oxidizing agent-potassium persulfate on heavy metal removal, dewatering performance and characteristic of sludge. The results showed that sludge dewatering performance was improved, the moisture content of sludge cake was decreased from 82.6% to 74.8%, specific cake resistance was reduced from 6.70×108S2/g to 5.43×108S2/g under the condition (2for initial pH, 1h for reaction time, 25℃ for temperature, 1.34g/g SS for K2S2O8 dosage). K2S2O8could effectively promote decomposition of the sludge floc. As a result, COD in the sludge supernatant was increased from 15.2mg/L to 187.0mg/L, TN in the sludge supernatant was increased from 6.03mg/L to 22.7mg/L, TP in the sludge supernatant was increased from 8.15mg/L to 12.7mg/L, and TSS in the sludge supernatant was decreased by 9.4%.The removal rates of tested heavy metals increased with increasing oxidant concentration, when the dosage of K2S2O8 was 2.01g/g SS, the removal rates of Pb, Zn, Cu and Cd in sludge could reach 63.90%, 87.10%, 86.40% and 84.25%, respectively. The removal rates of heavy metals had been basically stable when the dosage was greater than 2.01g/g SS. However, the efficiency of removal could increase with decreasing pH within a certain range. The heavy metals in the sludge were transferred to the supernatant after K2S2O8 oxidation. Then, calcium oxide of 0.075% concentrations was added to the supernatant, the pH value in the supernatant increased, as a result, the contents of heavy metals could be removed by 16.95% for Pb, 54.70% for Zn, 58.90% for Cu, and 21.95% for Cd in supernatant, respectively, the TN and TP in the liquid could be obviously improved.
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