Fenton氧化联合人工湿地处理污泥中的重金属

针对单独应用Fenton氧化技术处理污泥的不足以及人工湿地在处理污水污泥方面的优势,以污水处理厂污泥浓缩池中含重金属污泥为对象,研究其依次经过Fenton氧化和人工湿地处理后重金属的去除效果及形态变化,以及污泥pH、TN和TP的变化情况。结果表明,Fenton氧化提高了污泥重金属的生物有效性,并促进了人工湿地对重金属的去除。Fenton氧化污泥经人工湿地处理后,Cu、Zn、Ni和Mn的去除率分别为67.2%、79.7%、37.0%和17.0%,与对照相比重金属的平均去除率提高了27.5%。经人工湿地处理后Fenton氧化污泥和原污泥重金属的生物有效性均降低。Fenton氧化污泥pH为4.4～4.6,经人工湿地处理后为6.2～7.1。人工湿地对Fenton氧化污泥和原污泥中TN的影响较小,而对TP表现出较高的去除率,2系统TP的去除率分别为51.1%和45.5%。

Fenton oxidation combined with constructed wetland for heavy metals treatment of sludge

In view of the drawbacks of Fenton oxidation in sludge treatment and the advantages of constructed wetlands in wastewater and sludge treatment, a new process of Fenton oxidation combined with constructed wetland for heavy metal treatment of sludge was used in the present study. The removal effect and the speciation distribution of heavy metals, and the pH, TN and TP changes of the sludge were investigated. The original sludge was taking from a thickener of a wastewater treatment plant. The results indicated that the Fenton oxidation process enhanced the bioavailability of heavy metals, and promoted the removal rates of heavy metals in constructed wetlands at the same time. The removal rates of Cu, Zn, Ni and Mn were 67.2%, 79.7%, 37.0% and 17.0%, respectively. The average removal rate was increased by 27.5% compared with the control treatment. The bioavailability of heavy metals of Fenton oxidized sludge and original sludge was simultaneously reduced after constructed wetland treatment. Before and after the constructed wetland treatment, the pH of the Fenton oxidized sludge was 4.4 to 4.6 and 6.2 to 7.1, respectively. The effect of constructed wetland on TN removal rate of the Fenton oxidized sludge and original sewage sludge was small, but the opposite tendency was observed with the TP, while TP removal rate was 51.1% and 45.5% of the Fenton oxidized sludge and original sewage sludge, respectively. This study provides a new method and idea for the sludge treatment and resource.