Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi, 110025, India,
Environ Sci Pollut Res Int. 2014 Mar;21(5):3218-29. doi: 10.1007/s11356-013-2235-3. Epub 2013 Nov 8.
Bagasse fly ash (BFA, a sugar industrial waste) was used as low-cost adsorbent for the uptake of arsenate and arsenite species from water. The optimum conditions for the removal of both species of arsenic were as follows: pH 7.0, concentration 50.0 μg/L, contact time 50.0 min, adsorbent dose 3.0 g/L, and temperature 20.0 °C, with 95.0 and 89.5 % removal of arsenate and arsenite, respectively. The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich adsorption isotherms were used to analyze the results. The results of these models indicated single-layer uniform adsorption on heterogeneous surface. Thermodynamic parameters, i.e., ΔG°, ΔH°, and ΔS°, were also calculated. At 20.0 to 30.0 °C, the values of ΔG° lie in the range of -4,722.75 to -4,878.82 and -4,308.80 to -4,451.73 while the values of ΔH° and ΔS° were -149.90 and -121.07, and 15.61 and 14.29 for arsenate and arsenite, respectively, indicating that adsorption is spontaneous and exothermic. Pseudo-first-order kinetics was followed. In column experiments, the adsorption decreased as the flow rate increased with the maximum removal of 98.9 and 95.6 % for arsenate and arsenite, respectively. The bed depth service time and Yoon and Nelson models were used to analyze the experimental data. The adsorption capacity (N o) of BFA on column was 3.65 and 2.98 mg/cm(3) for arsenate and arsenite, respectively. The developed system for the removal of arsenate and arsenite species is economic, rapid, and capable of working under natural conditions. It may be used for the removal of arsenic species from any contaminated water resources.
蔗渣飞灰（BFA，一种糖业工业废料）被用作从水中去除砷酸盐和亚砷酸盐的低成本吸附剂。去除这两种砷的最佳条件如下：pH 值 7.0，浓度 50.0 μg/L，接触时间 50.0 min，吸附剂剂量 3.0 g/L，温度 20.0°C，砷酸盐和亚砷酸盐的去除率分别为 95.0%和 89.5%。采用 Langmuir、Freundlich、Temkin 和 Dubinin-Radushkevich 吸附等温线对结果进行分析。这些模型的结果表明，吸附是在非均相表面上进行的单层均匀吸附。还计算了热力学参数，即ΔG°、ΔH°和ΔS°。在 20.0 至 30.0°C 时，ΔG°的值在-4,722.75 至-4,878.82 和-4,308.80 至-4,451.73 范围内，而ΔH°和ΔS°的值分别为-149.90 和-121.07，和 15.61 和 14.29 对于砷酸盐和亚砷酸盐，分别表示吸附是自发的和放热的。遵循准一级动力学。在柱实验中，随着流速的增加，吸附量减少，砷酸盐和亚砷酸盐的最大去除率分别为 98.9%和 95.6%。使用床层深度工作时间和 Yoon 和 Nelson 模型来分析实验数据。BFA 在柱上对砷酸盐和亚砷酸盐的吸附容量（N o）分别为 3.65 和 2.98 mg/cm³。开发的去除砷酸盐和亚砷酸盐的系统具有经济、快速和能够在自然条件下工作的特点。它可用于去除任何受污染水源中的砷物种。
