酸改性活性炭对含锑矿坑废水的吸附研究

Method of Removing Sb2+ from Mine Water by Acid Modified Activated Carbon Adsorption

摘要: 为使矿井废水达到地表三类水的排放要求，针对低浓度Sb²⁺难以去除的特点，我们主要采用酸改性活性炭两级吸附工艺对Sb²⁺进行吸附处理。通过吸附剂优选实验，单因素和正交试验确定了，酸改性活性炭在pH值为5，吸附时间为2.0 h，投药量为5 g/L时能使Sb²⁺降到0.02 mg/L以下，达到地表水III类水体标准。BET、SEM机理分析表明，酸改性活性炭比表面积得到增大，杂质减少，孔道被疏通；Boehm滴定法得出酸性表面官能团的含量明显增加。酸改性活性炭对Sb²⁺的吸附情况符合Langmuir方程，吸附属于多单层覆盖；其吸附过程遵循准二级动力学模型，相s关系数达到0.994。

Abstract: To meet “The Environmental Quality Standard for Surface Water” III kind of water standard re-quirement, according to the characteristic of low concentration Sb²⁺ is difficult to remove, we mainly adopt acid modified activated carbon two-stage adsorption process to deal with Sb²⁺. Adsorbent optimization experiment, single factor and orthogonal test determine that acid modified activated carbon works well for Sb²⁺ remove, with the optimal processing parameters as pH is 5, adsorption time is 2.0 h, coagulant dosage is 5 g/L. BET, SEM analysis showed the specific surface area increased, reducing impurity, channel unblocked. In addition, Boehm concluded that acidic surface functional groups increased obviously. Finally, the fit of the adsorption isotherm for modified activated carbon and Sb²⁺ follows Langmuir adsorption isotherm which belongs to monolayer coverage. It obeys a pseudo-second order kinetic model and the correlation coefficient is 0.994.