颗粒活性炭对水中典型医药类物质的吸附特性  

Adsorption characteristics of granular activated carbon to typical pharmaceuticals in water

作　　者：高宁[1] 卜龙利[1] 刘嘉栋[1] 赵佩[1] 冯奇奇 谭娜[1] 

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《环境工程学报》2016年第8期4289-4297,共9页Chinese Journal of Environmental Engineering

基　　金：陕西省教育厅专项(12JK0640)

摘　　要：通过静态与动态吸附实验考察了颗粒活性炭对水中4种典型医药类物质降固醇酸(CA)、卡马西平(CBZ)、萘普生(NAP)和双氯芬酸(DCF)的吸附特性。首先在比较木质炭(MAC)和椰壳炭(YAC)对药物吸附效果和表征测试基础上,优选YAC为实验活性炭。静态实验研究发现,当YAC投加量133 mg·L^(-1),温度25℃和转速150 r·min-1时,CA、CBZ、NAP和DCF的平衡吸附量分别为2.48、3.0、2.74和2.52 mg·g-1,YAC对4种药物的吸附强弱为:CBZ>NAP>DCF>CA;4种药物的吸附均符合假二级吸附动力学模型和Friendlich等温吸附模型,吸附速率受化学吸附、颗粒内扩散、表面吸附和液膜扩散等颗粒外扩散过程的控制;YAC对药物的吸附能力与其p Ka、lg Kow和水溶液中的存在状态等有关。通过YAC对超纯水溶液、污水厂过滤前后二级出水中4种目标物的去除率比较,发现污水中的离子强度是降低目标物去除率的主要因素,它减弱了目标物与活性炭的静电作用力,而溶解性有机物由于竞争椰壳炭上的吸附点位在一定程度上也降低了其去除率。YAC固定床动态吸附穿透实验表明,YAC对CBZ的吸附性能最强、CA最弱,动态与静态实验结果是一致的。Adsorption of four typical pharmaceutical compounds（ clofibric acid,carbamazepine,naproxen,and diclofenac） on granular activated carbon was evaluated by batch and dynamic experiments. Coconut shellbased activated carbon was selected as the activated carbon adsorbent for the present experiments based on comparison of the adsorption efficiency and characterization of charcoal-based and coconut shell-based activated carbon.At a carbon dosage of 133 mg·L^-1,the equilibrium adsorption capacities of coconut shell-based activated carbon for clofibric acid,carbamazepine,naproxen,and diclofenac were 2. 48,3. 0,2. 74,and 2. 52 mg·g- 1,respectively. Bottles containing each sample were sealed and shaken at 150 r·min- 1at 25 ℃. Clofibric acid was the most poorly adsorbed,followed by diclofenac,whereas carbamazepine was the most effectively adsorbed. The adsorption kinetics and linear isotherm model obtained are best described by a pseudo-second-order kinetic model and the Freundlich isotherm model,respectively. The adsorption rate was influenced by chemical-adsorption,intrapartical diffusion,surface adsorption,and film diffusion. The adsorption capacity of the coconut shell-based activated carbon for the pharmaceuticals was found to be related to the p Ka,lg Kow,and the solution conditions. The comparison of the removal of the four target compounds from ultrapure water,unfiltered effluent,and filtered effluent by coconut shell-based activated carbon showed that the ionic strength of the wastewater was the key factor,leading to diminished electrostatic interactions between the activated carbon and pharmaceuticals. Dissolved organic compounds decreased the removal of target compounds to some extent by competing for the adsorption sites in activated carbon. It indicated that carbamazepine was the most adsorbable,and clofibric acid was the least among the four pharmaceuticals by fixed bed column operation on coconut shell-based activated carbon,which was in agreement with batch experiment.

关 键 词：颗粒活性炭 医药类物质 吸附动力学 吸附等温线 离子强度 固定床吸附 

分 类 号：X703.1[环境科学与工程—环境工程]