Fenton法处理垃圾渗滤液MBR-NF浓缩液

采用Fenton法处理MBR-NF浓缩液,考察了FeSO4·7H2O投加量、n(H2O2)/n(Fe2+)投加比、初始pH对渗滤液MBR-NF浓缩液处理效果的影响,并在最佳实验条件下,探讨浓缩液富里酸(FA)、亲水性有机物(HyI)组分在Fenton氧化前后组成的变化。研究结果表明,在FeSO4·7H2O投加量为0.055 mol/L、n(H2O2)/n(Fe2+)投加比为4、初始pH为7.58时,对COD、腐植酸(UV254)、色度(CN)的去除率分别为79.6%、93.7%和97.8%。Fenton氧化后,浓缩液中有机物组分含量发生了较大变化,腐植酸含量下降,HyI成为渗滤液溶解性有机物主要成分。紫外-可见光谱表明,Fenton法对FA去除效果较好,而对HyI氧化效果较差;傅立叶红外光谱显示,经Fenton氧化后,FA的结构发生了明显变化,而HyI则变化不明显。

Treatment of MBR-NF concentrate of landfill leachate by Fenton process

The laboratory-scale experiments were conducted to investigate treatment performance of MBR-NF concentrate of landfill leachate by Fenton process. The affecting factors of dosage of FeSO₄·7H₂O, H₂O₂/ Fe²⁺ ratio (molar basis) and initial pH value on removal efficency were optimised. Meanwhile, the changes of compositions of fulvic acid (FA) and hydrophilic organic matter (HyI) fractions in the concentrate during Fenton process were discussed under the optimal conditions. The results showed that the optimal operating conditions were as follows: FeSO₄·7H₂O dosage of 0.055 mol/L, n(H₂O₂)/n(Fe²⁺) ratio of 4 and initial pH of 7.58. Under these conditions, the removal efficencies of COD, UV₂₅₄, and CN reached 79.6%, 93.7% and 97.8%, respectively. During Fenton process, the organic composition of the concentrate varied significantly. The content of humic substances (HS) decreased, and the HyI fraction shifted the dominating composition of dissolved organic matter. The UV spectra demonstrated that Fenton oxidation had a high removal efficency for FA,while less effective for HyI. Fourier-transform infrared spectra exhibited the significant changes of FA structure, while few in HyI.