Fenton试剂对垃圾渗滤液中腐殖酸的去除特性

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)，COD_Cr，TOC，腐殖酸对COD_Cr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COD_Cr和UV₂₅₄的去除效果. 结果表明:在试验范围内，UV₂₅₄去除率(48.5%～78.2%)高于COD_Cr去除率(40.3%～62.5%)；腐殖酸对COD_Cr去除的贡献比(α>0.77)远高于反应前(α_〖WTBZ〗00.61)，说明腐殖酸的降解影响和控制着整个体系COD_Cr的去除. 混凝作用(COD_{Cr coag}，UV254 coag)受氧化作用(COD_{Cr oxid}，UV254 oxid)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240 mmol/L，c(Fe2+)为40 mmol/L，反应时间为2 h时，COD_Cr和UV₂₅₄的氧化/混凝去除率比最大(φCOD_Cr8.6，φ _<sub>UV2546.0)，COD_Cr，UV₂₅₄，HA和FA去除率分别达到62.5%，78.2%，95.0%和62.7%. 

Removal Performance of Humic Substances in Landfill Leachate by Fenton Reagent

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 COD_(Cr) in the leachate and relative content of humic acids (UV_(254)) at different initial pH, dosage of H_2O_2 and Fe~(2+) were compared using gross organic parameters such as UV_(254), chemical oxygen demand (COD_(Cr)), total organic carbon (TOC), the ratio of COD_(Cr) removal of humic substances to overall COD_(Cr)(α) and the ratio of COD_(Cr) removal by oxidation to that by coagulation.The results show that the UV_(254) removal efficiency (from 48.5% to 78.2%) is higher than that of COD_(Cr) (from 40.3% to 62.5%), and the ratio of COD_(Cr) removal of humic substances to overall COD_(Cr)(α>0.77) is higher than that before the Fenton reaction (α_0=0.61).This demonstrates that the degradation of humic substances controls the overall COD_(Cr) removal.On the other hand, the results highlight the role of oxidation in controlling the efficiency of removal of COD_(Cr) by coagulation, such that high oxidation efficiency may cause relatively low coagulation.The UV_(254) and COD_(Cr) removal by coagulation (COD_(Cr coag), UV_(254 coag)) is more than those by oxidation (COD_(Cr oxid), UV_(254 oxid)) under the ratio of c(H_2O_2)/c(Fe~(2+)) lower than 1.2, and is less under the condition of the ratio of c(H_2O_2)/c(Fe~(2+)) higher than 2.Under the most favorable conditions (initial pH=4.0, c(H_2O_2)=240 mmol/L, c(Fe_(2+))= 40 mmol/L, 2 h reaction time), the ratio of COD_(Cr) and UV_(254) removal oxidation to coagulation was 8.6 and 6.0, and the removal efficiencies of COD_(Cr), UV_(254), humic acid (HA) and fulvic acid( FA) were 62.5%, 78.2%, 95.0% and 62.7% respectively.