High concentrations of arsenic (As) in groundwater pose a great threat to human health. The motivation of this study was to provide a practical solution for As-safe water in As geogenic areas using granular TiO2 (GTiO(2)). The kinetics results indicated that the As (III/V) adsorption on GTiO(2) conformed to the Weber-Morris (WM) intraparticle diffusion model. The Langmuir isotherm results suggested that the adsorption capacities for As (III) and As (V) were 106.4 and 38.3 mg/g, respectively. Ion effect study showed that cationic Ca and Mg substantially enhanced As (V) adsorption, whereas no significant impact was observed on As (III). Silicate substantially decreased As (V) adsorption by 57 % and As (III) by 50 %. HCO3 (-) remarkably inhibited As (V) adsorption by 52 %, whereas it slightly reduced As (III) adsorption by 8 %. Field column results demonstrated that similar to 700 mu g/L As was removed at an empty bed contact time (EBCT) of 1.08 min for 968 bed volumes before effluent As concentration exceeded 10 mu g/L, corresponding to 0.96 mg As/g GTiO(2). Two household filters loaded with 110 g GTiO(2) in the on-off operational mode can provide 6-L/day As-safe drinking water up to 288 and 600 days from the groundwater containing similar to 700 mu g/L As and similar to 217 mu g/L As, respectively. Integration of batch experiments and column tests with systematic variation of EBCTs was successfully achieved using PHREEQC incorporating a charge distribution multisite complexation (CD-MUSIC) model and one-dimensional reactive transport block.
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机译:地下水中高浓度的砷(As)对人类健康构成了巨大威胁。这项研究的目的是为使用粒状TiO2(GTiO(2))的As地质成因地区的As-safe水提供一种实用的解决方案。动力学结果表明,GTiO(2)上的As(III / V)吸附符合Weber-Morris(WM)颗粒内扩散模型。 Langmuir等温线结果表明,As(III)和As(V)的吸附容量分别为106.4和38.3 mg / g。离子效应研究表明,阳离子Ca和Mg显着增强了As(V)的吸附,而对As(III)则没有观察到显着影响。硅酸盐显着降低了As(V)吸附57%和As(III)50%。 HCO3(-)显着抑制了As(V)吸附52%,而将As(III)吸附略微降低了8%。现场柱结果表明,在废水中As浓度超过10μg / L(相当于0.96 mg As / g GTiO)之前,在968床体积的空床接触时间(EBCT)为1.08 min时除去了约700μg / L的As。 (2)。在开/关操作模式下,两个装有110 g GTiO(2)的家用过滤器可从含约700μg / L As和类似物的地下水中提供多达288和600天的6升/天安全饮用水。分别达到217μg / L As。使用PHREEQC成功地将批处理实验和柱测试与EBCT的系统变化相结合,使用了带有电荷分布多位络合(CD-MUSIC)模型和一维反应性转运嵌段的PHREEQC。
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