Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Ming-Shung, Chiayi County, 62102, Taiwan; School of Civil Engineering and Surveying and International Centre for Applied Climate Science, University of Southern Queensland, Toowoomba, Australia.
Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Ming-Shung, Chiayi County, 62102, Taiwan.
Environ Pollut. 2019 Oct;253:768-778. doi: 10.1016/j.envpol.2019.07.048. Epub 2019 Jul 15.
The removal of arsenic from groundwater is an important issue for environmental safety and human health. Research focused on the comparative assessment of arsenic removal from arsenic-bearing groundwater and arsenic-containing-synthetic water (2 mg/L) using natural magnetic material (NMM) (rock) and synthesized magnetic material (SMM) by Bacillus pasteurii and humic acid. The arsenic-bearing groundwater (97.56 ± 0.05 μg/L) exceed the WHO limit (10 μg/L) of arsenic concentration for drinking water. The NMM contains dominantly magnetite, hematite, ferrihydrate, coesite, quartz, and stishovite. The NMM of natural rock exhibited the existence of iron (6.25-8.86% FeO), which is widespread and important component in sedimentary rocks. The investigation on vibrating sample magnetometers (VSM) of NMM and SMM demonstrated the typical magnetization properties, which can be separated after arsenic removal process. The thermogravimetric analysis (TGA) of SMM displayed the existence of organic matter decomposition during particle synthesis. The TEM and SEM exhibited the nanoparticle particle formation within the range of 10-39 nm (10-20 nm particle FeO through B. pasteurii). FTIR spectrum (before and after removal of arsenic) indicated the existence and binding nature in between arsenic and iron. >90% of arsenic was removed from arsenic-bearing groundwater using FeO, FeO (N-Environment), FeO with humic acid, and FeO with B. pasteurii after 25 min, 8 min, 13 min and 120 min, respectively. In case of NMM in Site-A, the arsenic removal was observed very fast as 85-87% within 30 s, whereas 95-99%, 93-95% and 88-91% removal detected using the sample of Site-A, Site-B, and Site-C respectively, after 120 min at natural pH (8.31 ± 0.05) of arsenic-bearing groundwater. Thus, NMM, (ecofriendly green material), can be applicable for arsenic removal from arsenic-bearing groundwater.
从地下水去除砷是环境安全和人类健康的一个重要问题。本研究聚焦于使用巴氏芽孢杆菌和腐殖酸合成的磁性材料（SMM）和天然磁材料（NMM）（岩石）从含砷地下水（97.56±0.05μg/L）和含砷合成水（2mg/L）中比较评估砷的去除。该含砷地下水超过世界卫生组织（WHO）规定的饮用水砷浓度（10μg/L）的限量。NMM 主要含有磁铁矿、赤铁矿、水铁矿、柯石英、石英和斯石英。天然岩石的 NMM 显示存在铁（6.25-8.86% FeO），铁是沉积岩中广泛而重要的成分。NMM 和 SMM 的振动样品磁强计（VSM）的研究表明存在典型的磁化特性，这些特性在砷去除过程后可以分离。SMM 的热重分析（TGA）显示在颗粒合成过程中存在有机物分解。TEM 和 SEM 显示了纳米颗粒在 10-39nm 范围内的形成（通过巴氏芽孢杆菌合成的 10-20nm 颗粒 FeO）。傅里叶变换红外光谱（FTIR）（砷去除前后）表明砷与铁之间存在和结合性质。使用 FeO、N 环境中的 FeO、腐殖酸中的 FeO 和巴氏芽孢杆菌中的 FeO 分别在 25min、8min、13min 和 120min 后，可将 90%以上的砷从含砷地下水中去除。在 Site-A 的 NMM 情况下，砷的去除速度非常快，在 30s 内即可达到 85-87%，而在天然 pH（8.31±0.05）下，分别使用 Site-A、Site-B 和 Site-C 的样品在 120min 后，可分别检测到 95-99%、93-95%和 88-91%的去除率。因此，NMM（环保绿色材料）可用于从含砷地下水中去除砷。
