College of Environmental Science and Engineering, Yangzhou University, Jiangsu Yangzhou 225127, P.R. China E-mail:
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100083, P.R. China.
Water Sci Technol. 2022 Oct;86(7):1653-1667. doi: 10.2166/wst.2022.303.
FeOOH as a naturally abundant, relatively low-cost and effective adsorbent have been gradually valued in wastewater field rich in arsenic pollution, which can make for environmental remediation. In this study, FeOOH samples included Gth1/Gth2 as goethite, Aka1/Aka2 as akaganéite, and Lep as lepidocrocite, were prepared and used as adsorbents, and adsorption kinetic and isotherm experiments of As(III) were analyzed. Meanwhile, the effects of pH, adsorbent content, arsenic initial concentration and electrolyte solutions on adsorption processes were also discussed in detail to study adsorption behaviors and mechanism. The results showed that As(III) could be effectively adsorbed on goethite, akaganéite and lepidocrocite, the adsorption equilibrium achieved after 24 h. When As(III) concentration ranged in 40 mg/L, the saturated adsorption amounts (mg/g) calculated by the Langmuir equation were 12.3 (Gth1), 7.50 (Gth2), 6.29 (Aka1), 23.4 (Aka2), and 17.7 (Lep). The increase of adsorbent and adsorbate levels was favorable to improve the adsorption capacities of As(III) within a certain range. Removal efficiency of As(III) with NaSO and NaHPO as electrolyte reduced by about 10% and 30%, respectively. Therefore, the appropriate parameters in the adsorption process for investigation were isomeric FeOOH of 1.0 g/L, pH 7.0 and NaNO as electrolyte. In simulated groundwater filter system initially with 200 μg/L of arsenic species at about pH 7.0, arsenic removal strength for five FeOOH adsorbents (0.8 g) was Aka2 > Aka1 and Gth1 > Lep and Gth2. Some differences were present in the infrared (IR) spectra of arsenic-loaded and original isomeric FeOOH. These outcomes could give the aim at seeking high efficient materials for the purification of arsenic contaminated groundwater and put out the suggestion.
FeOOH 作为一种天然丰富、成本相对较低且高效的吸附剂，在富含砷污染的废水中逐渐受到重视，可用于环境修复。本研究制备了 Gth1/Gth2 为针铁矿、Aka1/Aka2 为纤铁矿和 Lep 为水铁矿三种 FeOOH 样品，并将其作为吸附剂，分析了 As(III)的吸附动力学和吸附等温线实验。同时，详细讨论了 pH 值、吸附剂含量、砷初始浓度和电解质溶液对吸附过程的影响，以研究吸附行为和机制。结果表明，As(III)可有效吸附于针铁矿、纤铁矿和水铁矿，24 h 后达到吸附平衡。当 As(III)浓度在 40 mg/L 范围内时，Langmuir 方程计算得到的饱和吸附量(mg/g)分别为 12.3(Gth1)、7.50(Gth2)、6.29(Aka1)、23.4(Aka2)和 17.7(Lep)。在一定范围内，增加吸附剂和吸附质水平有利于提高 As(III)的吸附容量。电解质 NaSO 和 NaHPO 的存在使 As(III)的去除率分别降低了约 10%和 30%。因此，吸附过程中适宜的参数为 1.0 g/L 的同晶 FeOOH、pH 7.0 和 NaNO3 作为电解质。在初始砷浓度约为 200μg/L、pH 7.0 的模拟地下水过滤系统中，五种 FeOOH 吸附剂(0.8 g)对砷的去除强度为 Aka2 > Aka1 和 Gth1 > Lep 和 Gth2。负载砷和原始同晶 FeOOH 的红外(IR)光谱存在一些差异。这些结果为寻找高效的砷污染地下水净化材料提供了目标，并提出了建议。
