| 铝盐混凝除砷影响因素及机制研究 |
| 摘要点击 3425 全文点击 1634 投稿时间：2012-10-22 修订日期：2013-01-04 |
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| 中文关键词 砷 混凝 铝盐 Al13形态 饮用水 |
| 英文关键词 arsenic coagulation aluminum coagulant Al13 species drinking water |
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| 中文摘要 |
| 铝盐混凝法被广泛应用于饮用水除砷工程.本研究选取三氯化铝(AlCl3)和富含Al13的聚合氯化铝(PACl)为絮凝剂,考察铝形态、pH值、腐殖酸(HA)以及共存阴离子对砷去除的影响与机制.结果表明,2种絮凝剂对As(Ⅲ)去除效能较低,对As(Ⅴ)去除率可达到近100%.pH影响混凝过程中铝形态分布,从而对铝盐混凝除砷效能产生重要影响.铝盐除砷效能与混凝过程中的Al13形态含量呈正相关关系.由于竞争吸附作用,HA和部分共存阴离子对砷的混凝去除产生负面影响.HA对混凝效能影响与絮凝剂投药量相关,投药量越低,则影响越大.PO43-和F-对混凝除砷效能影响显著,SiO32-、CO32-和SO42-对混凝除砷效能影响较小.本研究将对饮用水强化混凝去除原水中砷具有指导意义. |
| 英文摘要 |
| Aluminum coagulants are widely used in arsenic (As) removal during the drinking water treatment process. Aluminium chloride (AlCl3) and polyaluminium chloride (PACl) which contains high content of Al13 were used as coagulants. The effects of aluminum species, pH, humic acid (HA) and coexisting anions on arsenic removal were investigated. Results showed that AlCl3 and PACl were almost ineffective in As(Ⅲ) removal while the As(Ⅴ) removal efficiency reached almost 100%. pH was an important influencing factor on the arsenic removal efficiency, because pH influenced the distribution of aluminum species during the coagulation process. The efficiency of arsenic removal by aluminum coagulants was positively correlated with the content of Al13 species. HA and some coexisting anions showed negative impact on arsenic removal because of the competitive adsorption. The negative influence of HA was more pronounced at low coagulant dosages. PO43- and F- showed marked influence during arsenic removal, but there was no obvious influence when SiO32-, CO32- and SO42- coexisted. The present study would be helpful to direct arsenic removal by enhanced coagulation during the drinking water treatment. |
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