基于Fe3+/EDTA-2Na的类芬顿污泥预处理技术

Renovated sludge pretreatment technology based on the Fenton-like processing method with Fe3+/EDTA-2Na

为解决芬顿技术在中性条件下氧化性能较低的问题,以浓缩池污泥为研究对象,应用Fe^3+/EDTA-2Na类芬顿技术处理污泥,对污泥脱水性能(污泥/泥饼含水率、污泥比阻(SRF)、毛细吸水时间(CST))、沉降性能(污泥沉降比(SV)、污泥容积指数(SVI))及破解性能(污泥质量浓度、溶解性COD(SCOD)、胞外聚合物(EPS))的改善情况进行了研究。结果表明,Fe^3+/EDTA-2Na类芬顿反应能起到强氧化作用调理污泥,且在原污泥pH值条件下效果优于传统芬顿法。Fe^3+/EDTA-2Na类芬顿反应后污泥/泥饼含水率分别降至97.94%和77.87%,CST仅为17s,SV和SVI分别降至29%和49.15mL/g,MLSS和MLVSS较原污泥分别降低41.35%和40.91%,且污泥上清液中SCOD、蛋白质、多糖溶出最多,对污泥脱水、沉降、破解性能的改善效果明显。

In order to solve the problem of low oxidation performance of Fenton process under the neutral conditions,the paper intends to make a comparison between the Fenton and Fenton-like processing method with Fe^3+/EDTA-2 Na for treating the content concentrated sludge.For the said purpose,we have made a comprehensive investigation of the 3 sets of parameters,including the sludge dewatering performance(such as the water content of sludge and mud cake,SRF and CST),the settlement performance(for example,SV and SVI) and the cracking performance(for instance,the sludge concentration,SCOD and EPS) in the paper.The results of the dewatering performance tests indicate that the water content of the sludge and mud cake,as well as the CST tend to decrease by 97.94%,77.87%,and 17 s,respectively.On the other hand,the dewatering performance of the Fe^3+/EDTA-2 Na Fenton-like process proves to be superior over the traditional Fenton one,whereas the parameters of SV and SVI tend to be reduced to 29% and 49.15 mL/g.What is more,the settlement performance of sludge has been obviously improved for the oxidizing ability of Fe^3+/EDTA-2 Na Fenton-like process has been made stronger than the Fenton process under the neutral pH.Besides,and,the OH radicals produced in the above said Fenton-like processing has become the key to the sludge dewatering success.And,since the granule of the sludge turns to be more compact and dense due to the spoilt sludge structure by OH radicals,the oxidizing ability of the Fe^3+/EDTA-2 Na Fenton-like process may become stronger under the neutral conditions,and,needless to regulate its pH value,the cracking performance has been made superior over the Fenton process.What is more,the removal efficiency of MLSS and MLVSS has been made a lot more reduced to as much as to 41.35% and 40.91%,accordingly and respectively.On the other hand,the high concentrations of SCOD as well as the proteins and polysaccharides of EPS in the sludge prove to be supernatant during the Fe^3+/EDTA-2 Na Fenton-like process.Furthermore,the concentration of TB-EPS can be made decreased while the proportion of LB-EPS and S-EPS tends to increase.All in all,the Fe^3+/EDTA-2 Na Fenton-like process can be made into a low-cost and easy-realizable technology to deal with the sewage sludge and achieve better performance than Fenton process under the neutral pH condition.