改性活性炭对饮用水中铬酸盐的去除特性研究

Study on chromate temoval properties by modified activated carbon in drinking water

研究了阳离子聚合物十六烷基三甲基氯化铵(CTAC)、癸基三甲基溴化铵(MTAB)以及三甲基正十四烷溴化铵(DTAB)对颗粒活性炭的改性特点以及改性后活性炭对饮用水中六价铬的去除效果。目的在于开发一种能有效去除饮用水中铬盐离子的吸附材料。研究中首先利用吸附平衡实验比较了未改性活性炭以及三种阳离子聚合物改性后活性炭对铬的吸附能力。结果表明:阳离子聚合物改性能有效提高活性炭对铬的吸附,同时CTAC改性后活性炭对铬盐的吸附效果要好于MTAB和DTAB。另外,活性炭对六价铬的吸附过程符合Langm iur吸附平衡模型以及二级动力学模型。阳离子聚合物在活性炭上的稳定性也是个重要的问题。对其检测的结果表明聚合物和活性炭的结合非常稳定,改性活性炭吸附六价铬的过程中阳离子聚合物的脱附量少于3%。

This paper investigated the effect of cationic polymers（CTAC,MTAB and DTAB） on granular activated carbon（GAC） and Cr（VI） removal by these modified carbons.The purpose was to develop an adsorbent that could effectively remove Cr（VI）.Adsorption balance tests were conducted to compare the adsorption capacities of virgin GAC and GACs modified to three cationic polymers.The results showed that cationic polymer modification was able to greatly improve carbon＇s adsorption for Cr（VI）.In addition,CTAC modified GAC manifested higher capacities than MTAB and DTAB.The langmiur adsorption balance model and pseudo-second-order kinetics models were found to describe well the Cr（VI） adsorption behavior on activated carbon.Also,the stability of polymer on carbon was another important issue.Results indicated that polymer attached strongly to carbon surface and less than 3% of the polymer desorbed during Cr（VI） adsorption.