Fenton试剂对垃圾渗滤液中腐殖酸的去除特性

Removal Performance of Humic Substances in Landfill Leachate by Fenton Reagent

采用Fenton试剂处理反渗透浓缩渗滤液，通过腐殖酸相对含量（UV254），CODC1，TOC，腐殖酸对CODCr去除的贡献比（α）及氧化／混凝去除率比（φ）等表征手段，比较不同初始pH，H2O2投量【c（H2O2）]和Fe2＋投量【c（Fe2＋）]对渗滤液CODCr和UV254的去除效果．结果表明：在试验范围内，UK254去除率（48．5％～78．2％）高于CODCr去除率（40．3％-62．5％）；腐殖酸对CODCr去除的贡献比（α〉0．77）远高于反应前（α0=0．61），说明腐殖酸的降解影响和控制着整个体系CODCr的去除．混凝作用（CODCrcoag,UV254coag）受氧化作用（CODCroxid,UV254oxid）的影响并与之拮抗，氧化作用越大混凝作用越小．当c（H2O2）/c（Fe2＋）〉2时，氧化作用占优势；当c（H2O2）／c（Fe2＋）〈1．2时，混凝作用占主导．当初始pH为4．0，c（H2O2）为240mmol／L，c（Fe2＋）为40mmol／L，反应时间为2h时，CODCr和UV254的氧化，混凝去除率比最大（φCODC=8．6，φUV254=6．0），CODCr，UV254,HA和FA去除率分别达到62．5％，78．2％，95．0％和62．7％．

The experiments focused on the treatment performance of humic substances （HS） in concentrated landfill leachate rejected by reverse osmosis （RO） by a Fenton reagent. The removal efficiency of CODc, in the leachate and relative content of humic acids （UV254） at different initial pH, dosage of H2O2 and Fe2＋ were compared using gross organic parameters such as UV254, chemical oxygen demand （CODCr）, total organic carbon （TOC） , the ratio of CODe, removal of humic substances to overall CODCr（α） and the ratio of CODCr removal by oxidation to that by coagulation. The results show that the UV254 removal efficiency （from 48.5% to 78.2% ） is higher than that of CODc,（ from 40. 3% to 62.5% ）, and the ratio of CODCr removal of humic substances to overall CODCr（ α 〉 0. 77 ） is higher than that before the Fenton reaction （α0 = 0. 61 ）. This demonstrates that the degradation of humic substances controls the overall CODCr removal. On the other hand, the results highlight the role of oxidation in controlling the efficiency of removal of CODCr by coagulation, such that high oxidation efficiency may cause relatively low coagulation. The UV254 and CODCr removal by coagulation （ CODCr coag, UV254coag） is more than those by oxidation （CODCr oxid, UV254 oxid ） under the ratio of c（ H2O2 ）/c（ Fe2＋ ） lower than 1.2, and is less under the condition of the ratio of c（ H2O2 ） /c（ Fe2 ＋ ） higher than 2. Under the most favorable conditions （ initial pH =4.0, c（H2O2） =240 mmol/L, c（Fe2＋ ） = 40 mmool/L, 2 h reaction time） , the ratio of CODCr and UV254 removal oxidation to coagulation was 8.6 and 6. 0, and the removal efficiencies of CODCr, UV254, humic acid （HA） and fulvic acid（FA） were 62.5% , 78.2% , 95.0% and 62.7% respectively.