University of Science & Technology Beijing, School of Civil and Resource Engineering, Beijing, 100083, China.
University of Science & Technology Beijing, School of Civil and Resource Engineering, Beijing, 100083, China.
Environ Pollut. 2019 Jun;249:843-850. doi: 10.1016/j.envpol.2019.03.065. Epub 2019 Mar 20.
A novel carbonaceous material (NCM), prepared by the pyrolyzation of the oily sludge of tank bottom, was proposed to remove Cr(VI) from a synthetic solution for the first time. The effects of initial Cr(VI) concentration, NCM dosage and initial solution pH on Cr(VI) removal and the adsorption kinetics, the adsorption isothem were investigated. The removal mechanism was studied by comparing the surface properties of NCM before and after the Cr(VI) removal. The results showed that NCM can effectively remove Cr(Ⅵ) from the synthetic solution with the increase of solution pH at equilibrium. At the initial Cr(Ⅵ) concentrations of 40, 100, 150 and 250 mg/L and NCM dosages of 1, 3, 6 and 8 g/L with initial solution pH of 2, the removal efficiency of Cr(VI) was 95.5, 96.8, 95.2 and 81.2%, and the solution pH at equilibrium reached 2.3, 3.5, 5.8 and 7.5, respectively. NCM was suitable for Cr(Ⅵ) removal while the initial Cr(VI) concentration was less than 100 mg/L and initial solution pH was lower than 2.5. Most of Cr(VI) was removed by the reduction of Fe and S in NCM to Cr(III) and with the generation of stable FeCrO. Some Cr(VI) may be removed by reacting with Fe and Ca to produce CaCrO and FeCrO on the NCM surface. The dissolution of CaAlSiO and CaS in the solution increased the solution pH at equilibrium. NCM has been proved to be a material with dual functions both chemical reduction and adsorption.
一种新型的碳质材料（NCM），由罐底油泥热解制得，首次被提出用于从合成溶液中去除 Cr(VI)。考察了初始 Cr(VI)浓度、NCM 用量和初始溶液 pH 值对 Cr(VI)去除的影响，以及吸附动力学和吸附等温线。通过比较 Cr(VI)去除前后 NCM 的表面性质，研究了去除机制。结果表明，NCM 可以在平衡时通过增加溶液 pH 值从合成溶液中有效去除 Cr(Ⅵ)。在初始 Cr(Ⅵ)浓度为 40、100、150 和 250mg/L，NCM 用量为 1、3、6 和 8g/L，初始溶液 pH 值为 2 的条件下，Cr(VI)的去除效率分别为 95.5%、96.8%、95.2%和 81.2%，平衡时溶液 pH 值分别达到 2.3、3.5、5.8 和 7.5。当初始 Cr(VI)浓度小于 100mg/L，初始溶液 pH 值低于 2.5 时，NCM 适合用于去除 Cr(VI)。大部分 Cr(VI)通过 NCM 中的 Fe 和 S 的还原作用转化为 Cr(III)并生成稳定的 FeCrO 而被去除。部分 Cr(VI)可能通过与 NCM 表面的 Fe 和 Ca 反应生成 CaCrO 和 FeCrO 而被去除。溶液中 CaAlSiO 和 CaS 的溶解增加了平衡时溶液的 pH 值。NCM 已被证明是一种具有化学还原和吸附双重功能的材料。
