碱热联合处理用于污泥强化脱水  

Application of Alkaline Thermal Treatment to Improve the Sludge Dewaterability

作　　者：李洋洋[1] 李欢[1,2] 金宜英[1] 聂永丰[1] 

机构地区：[1]清华大学环境科学与工程系,北京100084 [2]清华大学深圳研究生院,广东深圳518055

出　　处：《高校化学工程学报》2010年第4期714-718,共5页Journal of Chemical Engineering of Chinese Universities

基　　金："十一五"国家科技支撑计划项目(2006BAC02A18);国家博士后科学基金项目(20080430368)

摘　　要：研究了城市污水厂脱水泥饼采用碱热联合预处理时,不同处理时间、温度、投碱量条件下的强化脱水效果,探讨了脱出液的资源利用方式。结果表明:碱的加入可以降低污泥热处理温度,达到相同含水率67%时投加NaOH可以降低40℃,投加Ca(OH)2可以降低80℃。在相同的热处理温度和处理时间下,加碱后脱水污泥最终的含水率可以降低6%～11%。在140℃、60min、Ca(OH)2投加量与污泥固体(TS)比为0.35的碱热处理条件下,含水率可达到60%,质量减少率为63.8%,每吨脱水污泥需要增加药剂费用10元,经济性较好。该条件下污泥脱出液的腐殖酸含量为6.79g·L-1,浓缩5倍后可以用于制取含腐殖酸叶面肥料。The effects of thermal treatment duration,temperature and alkaline addition dose on the alkaline thermal pretreatment process for sludge to improve its dewaterability were investigated,and the utilizing method of the dewatered effluent was discussed.The results show that,with the assistance of NaOH or Ca（OH）2,the temperature of thermal sludge treatment can be decreased by 40℃ or 80℃ to achieve the same dewatering degree.When taking the same temperature and treatment duration,the moisture content （MC） of the dewatered sludge with application of alkaline can be reduced by 6%～11% compared with that with only thermal treatment.Using the conditions of 140℃,Ca（OH）2/TS of 0.35 and treatment duration of 60 min,the moist content of the sludge after treatment can be reduced to 60%,while the mass reduction ratio can reach 63.8%.At the same time,the fee of Ca（OH）2 addition is only 10 Yuan·t-1 and it is quite economical.Under above conditions,the content of humic acid in the dewatered effluent is 6.79 g·L-1,and it can be used to make humic acid fertilizer when it is concentrated 5 times.

关 键 词：污泥 脱水 碱热处理 腐殖酸 

分 类 号：X705[环境科学与工程—环境工程]