芬顿与氧化钙联合处理填埋库污泥的力学特性

Mechanical properties of landfill sludge conditioned by Fenton’s reagent with calcium oxide

面对城市生活污泥填埋库容趋于饱和的现状,亟需研究开发城市生活污泥的减量化及资源化技术。以填埋库污泥和新鲜污泥为研究对象,进行岩土工程特性实验,发现填埋库污泥有机质含量及含水率远低于新鲜污泥。通过固结实验和直剪实验,分别对比、分析了未加药剂的填埋库污泥和药剂调质填埋库污泥的固结系数、渗透系数和抗剪强度变化规律。结果表明:填埋库污泥在pH为4时,芬顿试剂(硫酸亚铁和过氧化氢)的最佳配比为Fe2+=8%、H2O2=12%;当氧化钙投加量增加时,调质污泥的压缩指数减小,抗剪强度略微增大;考虑到联合处理后污泥的资源化利用、强碱性对环境的影响和处理成本,在实际污泥处理工程中,氧化钙投加量15%是较为合适的添加量,且效果优于常用的氯化铁药剂调制污泥。经芬顿与氧化钙联合处理的填埋库污泥抗剪强度满足填埋库要求,能够实现减容减量,对填埋库污泥后续资源化利用具有一定的指导意义。

Aiming at the saturation of the storage capacity of urban domestic sludge landfill,it’s urgent to analyze the reduction and recycling of landfill sludge.A series of tests were conducted to investigate geotechnical properties of landfill sludge and waste-activated sludge.Experimental results showed that the landfill sludge had much lower organic content and water content than the waste-activated sludge.Through the experiments of consolidation and direct shear,the variations of the consolidation coefficient,permeability coefficient and shear strength were compared and analyzed between unconditioned and conditioned landfill sludge with reagent.The results showed that the best ratio of Fenton’s reagent was determined as Fe2+=8%and H2 O2=12%at pH=4.The compression index decreased and shear strength increased with the increase of calcium oxide dosage.Considering the resource utilization of joint treated landfill sludge,the impact of strong alkalinity on the environment and the treatment cost,15%calcium oxide dosage was an appropriate one for sludge treatment,and its conditioning effect was better than often-used FeCl3.Moreover,the shear strength of the conditioned landfill sludge by Fenton’s reagent with calcium oxide can meet the requirements in landfill and sludge volume can be reduced.The test results provide a significant reference for the subsequent reclamation of landfill sludge.