改性镁铝水滑石的合成及其对水中Cu^2＋的去除性能研究  

THE SYNTHESIS OF MG-AL LAYERED DOUBLE HYDROXIDE INTERCALATED WITH EDTA ANION AND APPLICATION TO THE ADSORPTION OF Cu^(2+) FROM AN AQUEOUS SOLUTION

作　　者：林楠[1] 沙宇[2] 

机构地区：[1]西北工业大学航空学院,陕西西安710072 [2]西北工业大学动力与能源学院,陕西西安710072

出　　处：《水处理技术》2008年第9期30-34,共5页Technology of Water Treatment

摘　　要：利用EDTA对重金属离子的螯合作用,将其作为有机阴离子插入到镁铝水滑石的层间,得到一种对溶液中重金属离子具有去除性能的有机-无机复合层状材料Mg-Al-EDTALDH。分析表明,当NaOH实际投加量大于理论计算值的1.2倍时,合成物的层间阴离子为EDTA4-和OH-;小于1.2倍时,层间阴离子为EDTA4-、HEDTA3-、Mg(EDTA)2-和OH-。在pH=5.0,这种材料能迅速同Cu2+发生化学吸附,当加入量按EDTA4-/Cu2+摩尔比为1:1时,对初始浓度为100 mg·L-1的Cu2+溶液,30 min内反应可达平衡,溶液中Cu2+的去除率在98%以上。主要原因是Cu2+在Mg-Al-EDTA LDH的层间形成Cu(EDTA)2-以及Cu2+同溶解出的Al3+发生共沉淀反应,使得溶液中的Cu2+减少。The synthesis of a scavenger, Mg-Al-EDTA LDH, which could adsorb heavy metal ions from an aqueous solution with a high concentration, by coupling Mg-Al layered double hydroxide with EDTA anion. The positive excess electric charge of host layer were fully neutralized by EDTA^4- and OH^- when the ratio in excess of the actual amount of NaOH in the EDTA solution to the stoichiometric quantity in excess is 1.2, and EDTA^4- ,HEDTA^3- , Mg （EDTA）^2- and OH in the interlayer of Mg-Al-EDTA LDH when the ratio is less than 1.2. In this case, the mole ratio of EDTA anion in the added Mg-Al-EDTA LDH to Cu^2＋ solution was set at 1.0, this material was found to have a capacity for rapid absorb Cu^2＋ from an aqueous at the pH of 5.0, and the concentration of Cu^2＋ decreased from 100 mg·L^-1 to less than 2 mg ·L^-1 within 30 min. The uptake of Cu^2＋ is attributed to both the formation of Cu （EDTA）^2- complex with EDTA anion in the interlayer of Mg-Al-EDTA LDH and coprecipitation with the dissolved Al^3＋.

关 键 词：镁铝水滑石 EDTA阴离子 铜离子 

分 类 号：TQ424[化学工程]