Deng Yang
Department of Civil, Architectural and Environmental Engineering, University of Miami, McArthur Building Room 325, 1251 Memorial Dr., Coral Gables, FL 33124-0630, USA.
J Hazard Mater. 2007 Jul 19;146(1-2):334-40. doi: 10.1016/j.jhazmat.2006.12.026. Epub 2006 Dec 15.
Municipal landfill leachate, especially mature leachate, may disrupt the performance of moderately-sized municipal activated sludge wastewater treatment plants, and likewise tend to be recalcitrant to biological pretreatment. Recently, Fenton methods have been investigated for chemical treatment or pre-treatment of mature leachate. In this paper, the results of laboratory tests to determine the roles of oxidation and coagulation in reducing the organic content of mature leachate during Fenton treatment are presented. The efficiencies of chemical oxygen demand (COD) oxidation and coagulation were tested, and the ratio of COD removal by oxidation to that by coagulation was assessed, under various operating conditions. Low initial pH, appropriate relative and absolute Fenton reagent dosages, aeration, and stepwise addition of reagents increased COD removal by oxidation and the importance of oxidation relative to coagulation. Simultaneous aeration and stepwise reagent addition allowed comparable treatment without initial acidification pH, due to the generation of acidic organic intermediates and the continuous input of CO2. On the other hand, high COD oxidation efficiency and low ferrous dosage inhibited COD removal by coagulation. At significantly high oxidation efficiency, overall COD reduction decrease slightly due to low coagulation efficiency. Under the most favorable conditions (initial pH 3, molar ratio [H(2)O(2)]/[Fe2+]=3, [H2O2]=240 mM, and six dosing steps), 61% of the initial COD was removed, and the ratio of COD removal oxidation to coagulation was 0.75. Results highlighted the synergistic roles of oxidation and coagulation in Fenton treatment of mature leachate, and the role of oxidation in controlling the efficiency of removal of COD by coagulation.
城市垃圾渗滤液，尤其是熟化渗滤液，可能会扰乱中型城市活性污泥废水处理厂的运行，并且同样往往对生物预处理具有抗性。最近，已对芬顿法用于熟化渗滤液的化学处理或预处理进行了研究。本文介绍了实验室测试结果，以确定氧化和混凝在芬顿处理过程中降低熟化渗滤液有机物含量方面的作用。在各种操作条件下，测试了化学需氧量（COD）氧化和混凝的效率，并评估了氧化去除COD与混凝去除COD的比例。低初始pH值、适当的相对和绝对芬顿试剂剂量、曝气以及试剂的逐步添加提高了氧化去除COD的效率以及氧化相对于混凝的重要性。由于酸性有机中间体的产生和CO2的持续输入，同时曝气和试剂逐步添加在无需初始酸化pH值的情况下实现了可比的处理效果。另一方面，高COD氧化效率和低亚铁剂量抑制了混凝对COD的去除。在氧化效率显著较高时，由于混凝效率低，总的COD去除率略有下降。在最有利的条件下（初始pH值为3，摩尔比[H(2)O(2)]/[Fe2+]=3，[H2O2]=240 mM，以及六个投加步骤），去除了61%的初始COD，氧化去除COD与混凝去除COD的比例为0.75。结果突出了氧化和混凝在芬顿处理熟化渗滤液中的协同作用，以及氧化在控制混凝去除COD效率方面的作用。
