天然浮石去除水中As(V)的试验研究  

Test on the adsorption of arsenate from the aqueous solution via the natural pumice

作　　者：王慧敏[1] 岳建华[2] 黄建洪[2] 董占能[1] 杨丽萍[2] 易皓[2] 邱锦荣 

机构地区：[1]昆明理工大学环境科学与工程学院,昆明650500 [2]环境保护部华南环境科学研究所,广州510655

出　　处：《安全与环境学报》2015年第5期214-218,共5页Journal of Safety and Environment

基　　金：公益性科研院所基本科研业务费专项资金重点项目(2000500101007)

摘　　要：通过静态吸附试验,研究了天然浮石对高砷地下水中As（V）的吸附去除效果及影响因素。结果表明,增加浮石投加量,As（V）的去除率随之逐渐升高,但当浮石投加量超过10 g/L时,继续增加浮石投加量,As（V）的去除率趋于平稳。随吸附时间延长,As（V）的去除率逐渐升高,9 h后吸附达到平衡。浮石对As（V）的吸附量随As（V）初始质量浓度增大而升高,而As（V）的去除率则随之降低。酸性条件下（p H=2~6）,浮石对As（V）的去除效果较好,当p H=4时,浮石对As（V）的去除率最高;在碱性条件下（p H〉7）,浮石去除As（V）的效果较差,并且,随p H值增大,As（V）的去除率降低。采用Langmuir和Freundlich等温吸附模型分别对吸附数据进行拟合,浮石对As（V）的吸附符合Langmuir等温吸附规律,其饱和吸附量为2.53 mg/g。采用准一级和准二级动力学模型对吸附平衡前的数据进行拟合,准二级动力学模型更符合浮石吸附As（V）的动力学过程。研究表明,天然浮石是一种能够有效吸附高砷地下水中As（V）的吸附剂。This paper attempts to present the results of our experimental test on the adsorption of arsenate from the aqueous solution via the natural pumice as an adsorbent for arsenate removal from the groundwater with high-content rate As. For our study purpose,we have done thorough exploration of the effects of the different adsorptive parameters,such as the adsorbent dosage,the contact time,the initial arsenate concentration and the solution p H in hoping to optimize the reaction conditions. In addition,we have managed to further interpret the adsorption data concerned by resorting to Freundlich and Langmuir models with the data gained from the kinetic studies and analyzed via the kinetic pseudo-first-order and pseudo-second-order model. The results of the aforementioned experiments can be generalized in the following manner： The removal rate of arsenate tends to increase with the increase of the mass ratio of pumice. And a pumice dosage of 10 g / L would be enough to remove arsenate as high as to 95. 15%.Furthermore,we have found that it would take 9 hours to get the adsorption equilibrium or balanced under the normal experimental conditions. Moreover,the adsorption rate of arsenate tends to be decreased while the amount of arsenate adsorbed increases with the increase of the initial arsenate concentration. The experimental experience tells us that over 90% of arsenate with the initial concentration of 10 mg / L can be removed by pumice. Furthermore,arsenate adsorption can also affected by changing the p H value. For example,the arsenate absorption by pumice tends to increase with the increase of p H value to 4 and then begins to fall whereas in contrast the arsenate sorption tends to drop steadily with the increase of p H value. Besides,the adsorption isotherm fitting results reveals that the adsorptive isotherm due to the arsenate adsorption with the help of pumice is in better accord with the Langmuir model than with that of Freundlich. For example,the monolayer adsorption capacity of the absorbent can be expecte

关 键 词：环境工程学 浮石 高砷地下水 吸附 动力学 

分 类 号：X703.1[环境科学与工程—环境工程]