Departments of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Chennai, 603203, India.
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Republic of Korea.
Chemosphere. 2021 Aug;277:130225. doi: 10.1016/j.chemosphere.2021.130225. Epub 2021 Mar 15.
Removal of toxic arsenite [As(III)] from the contaminated surface and groundwater is essential for human health. However, direct arsenite removal is difficult compared to arsenate [As(V)]. Therefore, the peroxidation of arsenite to arsenate is vital for its effective removal from water. Herein, we investigated the removal efficiency of arsenic from groundwater by oxidizing it with UV activated potassium persulfate (KPS) and subsequently adsorbing it on iron oxide impregnated granular activated carbon (FeO/GAC). A batch experiment was carried out to determine the adsorption kinetics and thermodynamics. Further, the effects of the adsorbent mass (FeO/GAC), C/Fe molar ratio, pH, arsenic concentration, competing anions, and humic acid in arsenic adsorption was studied. The characterization of FeO/GAC adsorbent was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and zeta potential measurements. Using the UV activated KPS and FeO/GAC, a ∼100% removal amount was achieved for 10 ppm of the arsenic solution in 1 h. Also, the effect of pH showed the highest removal efficiency in the pH range of 6.0-7.0 and it decreased dramatically at higher and lower pH values. The groundwater collected from Cheongyang in South Korea was spiked with 10 ppm of the arsenic (III) and more than 82% removal of arsenic was achieved in 90 min even in the presence of natural contaminants. Therefore, the results suggest that the UV activated KPS with FeO/GAC provides an effective method for treating highly-arsenic-contaminated water sources and this may be a viable alternative method over the existing methods.
从受污染的地表水和地下水中去除有毒的亚砷酸盐 [As(III)] 对人类健康至关重要。然而，与砷酸盐 [As(V)] 相比，直接去除亚砷酸盐较为困难。因此，将亚砷酸盐氧化为砷酸盐对于从水中有效去除砷至关重要。在此，我们研究了用紫外线激活过硫酸钾 (KPS) 将地下水氧化并随后用氧化铁浸渍颗粒活性炭 (FeO/GAC) 吸附砷的方法来去除地下水中砷的效率。进行了批处理实验以确定吸附动力学和热力学。此外，还研究了吸附剂质量（FeO/GAC）、C/Fe 摩尔比、pH 值、砷浓度、竞争阴离子和腐殖酸对砷吸附的影响。通过扫描电子显微镜 (SEM)、X 射线衍射 (XRD)、X 射线光电子能谱 (XPS)、Brunauer-Emmett-Teller (BET) 和动电电位测量对 FeO/GAC 吸附剂进行了表征。使用紫外线激活的过硫酸钾和 FeO/GAC，在 1 小时内可以去除 10ppm 砷溶液中的约 100%的砷。此外，pH 值的影响表明在 pH 值为 6.0-7.0 的范围内去除效率最高，而在更高和更低的 pH 值下则急剧下降。在韩国朝阳采集的地下水被加入了 10ppm 的砷 (III)，即使在存在天然污染物的情况下，在 90 分钟内也能实现超过 82%的砷去除率。因此，结果表明，FeO/GAC 与紫外线激活的 KPS 联合提供了一种处理高砷污染水源的有效方法，这可能是现有方法之外的可行替代方法。
