活性炭吸附饮用水中三卤甲烷的实验研究

Experimental study on adsorption of trihalomethane in drinking water by activated carbon

采用活性炭吸附方法控制饮用水中的三卤甲烷(THMs)。对筛选的活性炭进行动态和静态吸附实验。在ACL_(1),ACL_(2),ACY,ACM 4种活性炭中,椰壳活性炭ACL_(1)对THMs的平衡吸附量最高;吸附行为更符合Freundlich经验模型。静态吸附实验结果表明,前1 h ACL_(1)对THMs的吸附效率较高,4 h内达到吸附平衡,当温度为27~36℃时,温度变化对活性炭吸附THMs的影响较小;当THMs的初始浓度为200μg·L^(−1)时,ACL_(1)对THMs的去除率大于90%;ACL_(1)对THMs的吸附效率依次为CHBr_(3)>CHClBr_(2)>CHCl_(2)Br>CHCl_(3)。动态吸附实验结果表明,当进水的THMs浓度为200μg·L^(−1)时,出水THMs达到《生活饮用水卫生标准》(GB5749—2006)所需的最大吸附时长分别为:CHCl_(3)8.1 h,CHCl_(2)Br 15.3 h,CHClBr_(2)15.6 h,CHBr_(3)16.5 h。

To control the amount of trihalomethane(THMs)in drinking water,this study employs activated carbon as adsorbent to adsorb THMs.Experimental results show that coconut shell activated carbon ACL_(1) has higher equilibrium adsorption capacity for THMs.The static adsorption test showed that activated carbon ACL_(1) presented higher adsorption efficiency for THMs within 1 hour,and reached adsorption equilibrium within 4 h.It was found that,the temperature had little effect on the adsorption of THMs by activated carbon within the range of 27‒36℃;When the initial concentration of THMs was twice the limit value of national standard,the removal rate of THMs was higher than 90%.The best adsorption effect of coconut shell activated carbon ACL_(1)was on CHCl_(3),followed by CHCl_(2)Br,CHClBr_(2)and CHBr_(3).The results of dynamic adsorption test showed that when the influent concentration of THMs were 200μg·L^(−1),the removal efficiency of THMs by the advanced treatment process meet the requirements of sanitary standard for drinking water(GB5749-2006).The adsorption effect of CHCl_(3),CHCl_(2)Br,CHClBr_(2)and CHBr_(3)was consistent with the static adsorption test.The maximum adsorption time was 8.1,15.3,15.6 and 16.5 h,respectively.