| Fenton法氧化/混凝作用去除腐殖酸的研究 |
| 摘要点击 5978 全文点击 4214 投稿时间：2009-05-30 修订日期：2009-08-01 |
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| 中文关键词 腐殖酸 Fenton 氧化 混凝 |
| 英文关键词 humic acids(HA) Fenton oxidation coagulation |
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| 中文摘要 |
| 采用Fenton法处理高浓度腐殖酸模拟废水，考察反应时间、初始pH、H2O2和Fe2+投量对腐殖酸COD、TOC、UV254、A400的影响，通过体系平均氧化态（η）、A465/A665、氧化/混凝作用去除COD比值（φ）、Zeta电位（ζ）等的变化研究氧化和混凝作用对腐殖酸去除的特性.结果表明，Fenton试剂能在较宽初始pH范围（2.0～5.0）内有效降解腐殖酸.当反应时间为2 h，腐殖酸A400降低值（78.2 %～94.5 %）比UV254（75.6 %～88.4 %）高，COD 去除率（50.8 %～62.5 %）比TOC（31.2 %～35.1 %）高.腐殖酸的去除由氧化作用（CODoxid）和混凝作用（CODcoag）共同完成.反应初始阶段腐殖酸主要通过氧化作用迅速降解去除.腐殖酸易被部分氧化为小分子有机物而不易矿化，过多Fe2+投量（［Fe2+］>0.08 mol/L）会使CODoxid下降.混凝主要通过电中和及吸附网捕作用进行，氧化作用影响混凝作用，高CODoxid导致低CODcoag；高H2O2投量下（［H2O2］>0.2 mol/L）Fe2+投量显著影响混凝作用对COD的去除. |
| 英文摘要 |
| Simulated high concentration humic acids (HA) wastewater was treated by Fenton process. The influence of reaction time, initial pH, H2O2 and Fe2+ dosage on the reduction results of COD, TOC, UV254, A400are presented. The changes of mean oxidation state (η), A465/A665., the ratio of COD removal by oxidation to that by coagulation (φ) and Zeta potential (ζ) were used to evaluate the roles of oxidation and coagulation in reducing HA during Fenton treatment. The results demonstrate that Fenton’s reagent can effectively degrade HA under a wide initial pH range (2.0-5.0), simultaneously the absorbance decrease in 400 nm was higher (from 78.2 % to 94.5 %) than that in 254 nm (from 75.6 % to 88.4 %) and the COD removal (from 50.8 % to 62.5 %) is higher than TOC removal (from 31.2 % to 35.1 %) in 2 h reaction time. The amount of HA is removed by both oxidation and coagulation. Oxidation played a primary role in removal of HA at the beginning of Fenton reaction. The large molecular weight component of HA appears to be easily degraded and the formations of low molecular persistent organic intermediate compounds are difficult to be mineralized. The COD removal efficiency by oxidation decreases over the ferrous dosage of 0.08 mol/L. Furthermore, the results reveal that HA removal by coagulation was reduced mainly by charge neutralization as well as adsorption bridge building. Results highlight the role of oxidation in controlling the efficiency of COD removal by coagulation, so high CODoxid may cause relatively low CODcoag. Meanwhile, ferrous dosage greatly influences COD removal by coagulation at high peroxide dosages over 0.2 mol/L. |
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