Department of Environmental Engineering, National I-Lan University, Ilan 26047, Taiwan, China; Continental Water Engineering Corporation, Taipei 10608, Taiwan, China.
Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 10608, Taiwan, China.
Water Sci Technol. 2022 Mar;85(5):1384-1399. doi: 10.2166/wst.2022.047.
This study involved novel-designed sludge biochar (SB) adsorbed for arsenic removal with lower operating costs and higher adsorption efficiency properties. Generally, biochar only relies on micropores for pollutant adsorption, but physical adsorption is not highly efficient for arsenic removal. Therefore, in order to improve the removal efficiency of arsenic by SB, diethylenetriamine (DETA) and FeCl were used in this study to modify the surface of SB by an immersion method. The objectives of this research are to obtain optimum operation conditions by assessing the effect of different Fe content, pH and initial concentration on adsorbing arsenic. This study is the first to use Density Functional Theory (DFT) to simulate and verify the adsorption mechanism of arsenic by SB. Results showed the presence of amine/iron oxyhydroxides functional groups greatly promoted SB surface activity and its arsenic adsorption potential. The surface area, pore volume and pore size of the SB were estimated to be 525 m g, 0.35 cm g and 8.71 nm, respectively. The DFT model result is the same as the result of arsenic adsorption performance with high adsorption energy (-246.3 kJmol) and shorter bond distances (1.42 Å), indicating strong chemical adsorption between arsenic and material. The reaction mechanism is divided into four pathways, including oxidation-reduction, complexation, electrostatic adsorption and pore adsorption.
本研究涉及新型设计的污泥生物炭（SB），其具有较低的操作成本和更高的吸附效率，可用于去除砷。一般来说，生物炭仅依靠微孔进行污染物吸附，但物理吸附对于去除砷的效率不高。因此，为了提高 SB 对砷的去除效率，本研究采用浸渍法用二乙三胺（DETA）和 FeCl3 对 SB 表面进行改性。本研究的目的是通过评估不同 Fe 含量、pH 值和初始浓度对吸附砷的影响，获得最佳操作条件。本研究首次使用密度泛函理论（DFT）模拟和验证 SB 吸附砷的机理。结果表明，胺/铁氢氧化物官能团的存在极大地促进了 SB 表面活性及其对砷的吸附潜力。SB 的比表面积、孔体积和孔径分别估计为 525 m2 g、0.35 cm3 g 和 8.71 nm。DFT 模型的结果与砷吸附性能的结果相同，具有高吸附能（-246.3 kJmol）和较短的键距（1.42 Å），表明砷与材料之间存在强烈的化学吸附。反应机制分为四个途径，包括氧化还原、络合、静电吸附和孔吸附。
