采用冷融技术对城市污水处理厂的剩余污泥进行了预处理,分析了剩余污泥在-18℃下冷冻不同时长并于室温下解冻后,污泥的沉降性能、脱水性能等的变化情况.试验结果表明剩余污泥经13h的冷冻作用后,污泥的沉降性能和脱水性能都有很大程度的提高,而污泥完全冻结后继续延长冷冻时间至22 h时,污泥的沉降性能和脱水性能并没有进一步的改善.结果还表明,随着冷冻时间的增加,剩余污泥的pH下降而SCOD上升.%The excess sludge of municipal sewage treatment plants has been pretreated by freezing/thawing technique. The changes of the settlement, dewatering and physicochemical performances of excess sludge are analyzed under the condition of -18 t, after it is frozen for different time lengths and defrozen at room temperature. The experimental results show that both of the settlement and dewatering performances of sludge are improved greatly after 13 h freezing treatment,but after the sludge has been frozen completely,and the freezing time continuously lengthened to 22 h, no further improvement can be made. The results also show that the pH of sludge decreases and SCOD increases with the lengthening of freezing time.
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