碱热联合处理对剩余污泥干燥特性影响  

Application of Alkaline Thermal Treatment to Improve Sludge Drying Performance

作　　者：李洋洋[1] 金宜英[1] 李欢[2] 聂永丰[1] 周岩岩[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》2011年第5期877-881,共5页Journal of Chemical Engineering of Chinese Universities

基　　金："十二五"国家科技支撑计划项目(2009BAC64B06)

摘　　要：研究了城市污水厂脱水泥饼在不同处理时间、温度、NaOH投加量的条件下进行碱热联合预处理后的千化效果，探讨了干化过程中污泥质量变化规律，并分析了改善干燥的机理、污泥减量效果及脱出液的资源利用方式。结果表明：与未任何处理及仅热处理的污泥相比，达到相同含水率50％时，碱的加入可以加速污泥破解，改善污泥干化性能，干燥效率可以分别提高（10—33）％、（11-25）％。碱热预处理温度的提高可以促进污泥破解，从而提高污泥后续的干燥速率。干燥至含水率为60％时，与未投碱时相比，碱热处理后干燥速率可以提高16．67％-28．57％。碱热处理时间增加可以缩短后续干化时间。达到含水率60％时。预处理45min比30min时的干化时间缩短了11％。140℃、60min、NaOH／TS=0．25时，该条件下污泥脱出液的腐殖酸含量为8．69g．L-1，浓缩4倍后可以用于制取含腐殖酸叶面肥料。An investigation was carried out on the effect of thermal alkaline pretreatment on sludge drying performance. Different parameters, such as the thermal treatment duration, temperature and NaOH dose, were tested to optimize the process of alkaline-thermal pretreatment process of sludge to improve its drying ability. The drying mechanisms and utilizing method of the dewatered effluent was discussed. Results show that, the efficiency of sludge drying after combined alkaline and thermal pretreatment can be increased by （10~33）% compared with that without pretreatment, or （11~25）% compared with thermal treatment only. Increasing the temperature of alkaline thermal pretreatment could promote sludge break, thereby enhance the efficiency of sludge drying. When sludge after pretreatment was dried to moisture content of 60%, compared with no alkaline treatment, the drying efficiency could increase （16.67-28.57）%. After 45 min of alkaline thermal pretreatrnent, the time consumed in the process of sludge drying to moisture content of 60% can be reduced by 11% compared with that after only 30 min of pretreatment. Using the optimized conditions of 140℃, NaOH/TS of 0.25 and treatment duration of 60 min, the content of humic acid in the dewatered effluent is 8.69 g.L-1. Therefore, it can be used to make humic acid fertilizer after it is concentrated 4 times.

关 键 词：污泥 干化 碱热处理 腐殖酸 

分 类 号：X705[环境科学与工程—环境工程]