| 不同组成活性污泥胞外聚合物吸附Cd2+、Zn2+特征 |
| 摘要点击 5395 全文点击 2658 投稿时间：2007-10-15 修订日期：2007-12-30 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 胞外聚合物 重金属 吸附 糖 蛋白质 |
| 英文关键词 extracellular polymeric substances (EPS) heavy metal adsorption sugar protein |
| DOI |
|
| 中文摘要 |
| 以蛋白质和糖含量比分别为2.5∶1、7∶1和9∶1的3种活性污泥胞外聚合物(extracellular polymeric substances, EPS)EPS1、EPS2、EPS3作为吸附剂，研究其对水中Cd2+、Zn2+的吸附效能.结果表明，EPS对Cd2+和Zn2+的吸附与其组成有关，EPS1、EPS2和EPS3对Cd2+和Zn2+吸附量分别约为19.5、 27、 17 mg/g和40.5、 47.5、 37 mg/g. 3种胞外聚合物对Cd2+、Zn2+吸附过程可在1 h内快速平衡.动力学拟合结果表明，EPS1对2种重金属的吸附速率最快，而EPS2对Cd2+、Zn2+的平衡吸附容量最高.Freundlich和Langmuir方程均可描述3种EPS对Cd2+、Zn2+的吸附过程，方程参数拟合结果表明2种金属同EPS之间存在多种作用方式.3种EPS的吸附热力学方程拟合系数均表明EPS对Zn2+的吸附稳定性、吸附能力和亲和力均比对Cd2+的吸附强；当EPS中糖所占比例增加时，其对重金属的吸附能力也提高，表明糖在吸附过程中起着重要作用. |
| 英文摘要 |
| Three types of extracellular polymeric substances (EPS), EPS1, EPS2 and EP3, with protein/sugar content ratio of 2.5∶1, 7∶1 and 9∶1, respectively, were investigated as sorbent for adsorbing Cd2+ and Zn2+ from wastewater. The experimental results showed that the adsorption efficiency of EPS toward Cd2+ and Zn2+ were dependent on the composition of EPS. The adsorptive capacities of EPS1, EPS2, EPS3 to Cd2+ were 19.5 mg/g, 27 mg/g, 17 mg/g and to Zn2+ 40.5 mg/g, 47.5 mg/g, 37 mg/g, respectively. Kinetic study showed that EPS1 has the highest reaction rate, while EPS2 has the highest adsorption capacity. All of the adsorption processes reached equlibrium within 1 h following both the Freundlich and Langmuir isotherms. The fitted parameters indicated that varied reactions may occur in EPS-metal adsorption process and EPS as adsorbent has much higher adsorption stabilization, adsorption ability and appetency to Zn2+ than to Cd2+. The adsorption capacity of EPS toward Cd2+ and Zn2+ increased with the sugar content, which suggests sugar is of great importance in the adsorption. |
|
|
|
