Treatment of landfill leachate using electrochemically assisted UV/chlorine process: Effect of operating conditions, molecular weight distribution and fluorescence EEM-PARAFAC analysis
Treatment of landfill leachate using electrochemically assisted UV/chlorine process: Effect of operating conditions, molecular weight distribution and fluorescence EEM-PARAFAC analysis
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DOI：
10.1016/j.cej.2015.10.017
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发表时间：
2016-02-15
影响因子：
15.1
通讯作者：
Zhou, Dejian
中科院分区：
文献类型：
--
作者：
Ye, Zhihong;Zhang, Hui;Zhou, Dejian
垃圾填埋场产生的渗滤液是一种污染严重的废水，其成分复杂，对环境影响较大。研究了在流动反应器中使用电化学辅助紫外/氯工艺 (UEC) 对生化处理的垃圾渗滤液进行深度处理。评估了 pH 值和电流密度对 UEC 工艺去除 COD 和 NH3-N 的影响。在pH值为5.0、电流密度为60 mA/cm(2)时，COD和NH3-N的去除率分别为77%和87%。单独的电化学工艺(EC)可以获得较高的NH3-N去除率和很低的COD去除率，相比之下，UEC工艺显着提高了COD的去除效率，而NH3-N的去除率提高幅度非常有限。处理8 h后，大部分NH3-N转化为N-2，渗滤液中残留少量氮化合物和氯胺。此外，监测了EC和UEC系统中活性氯和氯离子的变化，并提出了UEC过程的可能机制。原位电产生的活性氯和光产生的自由基物种应负责垃圾渗滤液的有效降解。处理8小时的总能耗和电流效率分别为216.5（kW·h/kg COD）和17.5%。此外，分子量（MW）百分比分布分析和激发发射矩阵（EEM）荧光光谱的PARAFAC分析表明，渗滤液中的有机物显着降解为小分子量组分。 (C) 2015 Elsevier B.V. 保留所有权利。
Leachate, a highly polluted wastewater, is generated from landfill containing complex compositions which have great impact on the environment. The advanced treatment of biochemically treated landfill leachate using electrochemically assisted UV/chlorine process (UEC) in a flow reactor was investigated. The effects of pH and current density on COD and NH3-N removal by UEC process were evaluated. At the pH value of 5.0, current density of 60 mA/cm(2), the removal efficiencies for COD and NH3-N were observed as 77% and 87%, respectively. The electrochemical process alone (EC) could obtain relatively high NH3-N removal but very low COD removal, compared with which, the UEC process significantly promoted the removal efficiency of COD while that of NH3-N increased to a very limited extent. Most of NH3-N was converted into N-2 and little nitrogen compounds and chloramines were remained in the leachate after 8 h treatment. Moreover, the variations of active chlorine and chloride ions were monitored in the EC and UEC systems, and a possible mechanism was proposed for the UEC process. The in situ electro-generated active chlorine and photo-generated radical species should be responsible for the efficient degradation of landfill leachate. The total energy consumption and current efficiency were 216.5 (kW h/kg COD) and 17.5%, respectively, for 8 h treatment. In addition, the molecular weight (MW) percentage distribution analysis and PARAFAC analysis of excitation emission matrix (EEM) fluorescence spectroscopy indicated that the organic matters in the leachate were significantly degraded into the fractions with small molecular weight. (C) 2015 Elsevier B.V. All rights reserved.