摘要
为研究汞和砷在胡敏酸上的吸附特性,从辽宁彰武采集了草炭土并用稀碱法提取胡敏酸。研究胡敏酸对Hg(Ⅱ)和As(Ⅲ)吸附作用,探讨温度(15、25、35、45℃)、pH(3,5,7,9)和离子强度(Ca2+,H2PO-4)对该吸附的影响,并计算吸附活化能。结果表明:温度与胡敏酸对Hg(Ⅱ)的吸附呈显著正相关,而对胡敏酸吸附As(Ⅲ)的影响较小;pH对胡敏酸吸附Hg(Ⅱ)也呈正相关,而胡敏酸对As(Ⅲ)的吸附以中性最好,酸性、碱性下吸附量均降低;Ca2+对Hg(Ⅱ)的吸附有明显的抑制作用,H2PO-4对As(Ⅲ)的吸附影响很小。对等温吸附实验结果拟合证明,胡敏酸对Hg(Ⅱ)和As(Ⅲ)等温吸附更符合Freundlich模型。对动力学吸附实验结果拟合证明,准二级动力学方程能很好地描述胡敏酸对Hg(Ⅱ)和As(Ⅲ)的吸附。Hg和As(Ⅲ)在胡敏酸的吸附活化能分别为23.06 k J·mol-1和2.65 k J·mol-1,表明Hg(Ⅱ)在胡敏酸上的吸附以化学吸附为主,As(Ⅲ)在胡敏酸上的吸附以物理吸附为主。
Humic acid was extracted from peatsoil collected from Zhangwu county Liaoning province. Batch experiments were performed to investigate the sorption of Hg（Ⅱ） and As（Ⅲ） on the humic acid. Effect of temperature（15,25,35,45 ℃）,pH（3,5,7,9） and ionic strength（Ca2 ＋,H2PO-4） on the sorption was also researched. Results indicated that sorption capacity of Hg（Ⅱ） and As（Ⅲ） on the humic acid was positively correlated with temperature,while temperature had little effect of As（Ⅲ） sorption on the humic acid. Sorption capacity of Hg（Ⅱ） on the humic acid was positively correlated with solution pH,while pH = 7,sorption capacity of As（Ⅲ） on the humic acid reached the highest. Ca2 ＋could reduce the sorption capacity of Hg（Ⅱ） on the humic acid while H2PO-4had few impact on the sorption of As（Ⅲ）. Sorption isotherm of Hg（Ⅱ） and As（Ⅲ）on humic acid could be better discribed with Freundlich equation. Experimental data were better fitted with Lagrangian pseudo-second-order sorption kinetics equation. The sorption activation energy of Hg（Ⅱ） on the humic acid was 23. 06 kJ·mol^-1and that of As（Ⅲ） was 2. 65 kJ·mol^-1. It indicated that sorption of Hg（Ⅱ） on the humic acid was controlled by chemical sorption while thjat of As（Ⅲ） on the humic acid was physical absorption mainly.
出处
《环境工程学报》
CAS
CSCD
北大核心
2017年第9期5275-5282,共8页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(41371325)
