摘要
目前水环境污染物成分复杂,常用的化学沉淀法已很难将重金属污染物分类去除并资源化利用,由此产生了大范围的危废污染环境,需要进行二次处理。利用离子印迹技术对壳聚糖基水凝微球进行改性,制备具有对Cr(VI)特异识别性能的吸附材料(CTS-IGB),对其在单一Cr(VI)溶液和模拟电镀废水中的吸附行为特征进行研究。研究结果表明:在20℃、pH值为3时,CTS-IGB在单一Cr(VI)溶液和模拟电镀废水中Cr(VI)的吸附量在180 min内分别达到37.4和44.3 mg/g,半饱和吸附时间仅分别为5.8和23.5 min;吸附行为符合准二级动力学。吸附等温线拟合表明吸附过程符合Freundlich模型;热力学参数表明吸附过程是放热反应,且吸附后无序度减小;相比于未改性壳聚糖水凝微球,CTS-IGB在共存离子(模拟电镀废液及其他双组份溶液)工况下对Cr(VI)的选择性提高32%~74%。该材料可作为潜在的吸附材料用于污染水环境中Cr(VI)的分离及回收。
At present,the composition of water environmental pollutants is complex,and it is difficult to classify and remove the heavy metal pollutants and recycle them using the common chemical precipitation method,resulting in a large number of hazardous wastes that pollute the environment and require secondary treatment.The substrate chitosan gel microspheres were modified through ion-imprinted technology to synthesis of CTS-IGB,and subsequently employed as adsorbents for Cr(VI)removal selectively from single Cr(VI)solutions and simulated electroplating wastewaters.The results indicated that the Cr(VI)adsorption capacity of CTS-IGB reached 37.4 mg/g and 44.3 mg/g in single Cr(VI)solution and simulated electroplating wastewaters,respectively,when the pH was 3 and temperature was kept at 20℃.And the semi-saturated time were 5.3 minutes and 5.6 minutes,respectively.The experimental Cr(VI)adsorption data well agreed with pseudo-second-order kinetic model.Freundlich isotherm model can best describe the equilibrium data of Cr(VI)adsorption.The thermodynamics parameters indicated that Cr(VI)adsorption on CTS-IGB was spontaneous,thermodynamically favorable and exothermic,and decreased at random.Comparing with the pristine chitosan gel microspheres,the Cr(VI)selective adsorption coefficient of CTS-IGB was increased by 32%~74%in the presence of coexisting ions.The CTS-IGB can be used as a potential adsorption material for the separation and recovery of Cr(VI)in polluted water environment.
作者
蔡伟成
郭牧林
CAI Weicheng;GUO Mulin(Research Center on New Materials in Hydraulic Structures of Ministry of Water Resources,Nanjing Hydraulic Research Institute,Nanjing 210029,China)
出处
《水利水运工程学报》
CSCD
北大核心
2021年第2期130-137,共8页
Hydro-Science and Engineering
基金
中央级公益性科研院所重点项目(Y418003)。
