Ma Zhiyao, Shan Chao, Liang Jialiang, Tong Meiping
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
Chemosphere. 2018 Feb;193:134-141. doi: 10.1016/j.chemosphere.2017.11.005. Epub 2017 Nov 4.
Selenium (Se) could enter the environment through different anthropogenic sources, posing potential health risk. The removal of trace Se(IV) from water by hematite coated magnetic nanoparticle (MNP@hematite) under different solution conditions was investigated through batch experiments. The adsorption capacity of Se(IV) by MNP@hematite was 25.0 mg/g.100 μg/L of Se(IV) could be rapidly decreased to below 10 μg/L by 0.1 g/L of MNP@hematite in 10 min. MNP@hematite could effectively remove Se(IV) in a wide pH range from 4 to 9. Se(IV) could form inner-sphere complex with MNP@hematite. Thus, the presence of chloride, nitrate, and sulfate (concentration of each anions <10 mM) did not affect the removal of Se(IV); whereas, carbonate (10 mM), silicate (1 mM), and phosphate (0.1 mM) yet reduced the adsorption efficiency by competing adsorption sites. Humic acid and alginate (up to 6 mg/L) did not have obviously influence on the removal of Se(IV). MNP@hematite particles were able to simultaneously remove Se(IV) and Sb(III) at trace level very efficiently in 10 min. The magnetic adsorbent can be easily recycled and regenerated in 10 mM NaOH for 15 min. In five consecutive cycles, the adsorption and desorption efficiencies were over 97% and 82%, respectively. MNP@hematite could be employed as effective adsorbent for Se(IV) removal from water.
硒（Se）可通过不同的人为来源进入环境，从而带来潜在的健康风险。通过批次实验研究了在不同溶液条件下，赤铁矿包覆磁性纳米颗粒（MNP@赤铁矿）对水中痕量硒（IV）的去除效果。MNP@赤铁矿对硒（IV）的吸附容量为25.0 mg/g。在10分钟内，0.1 g/L的MNP@赤铁矿可将100 μg/L的硒（IV）迅速降至10 μg/L以下。MNP@赤铁矿在4至9的宽pH范围内能有效去除硒（IV）。硒（IV）可与MNP@赤铁矿形成内球络合物。因此，氯化物、硝酸盐和硫酸盐（每种阴离子浓度<10 mM）的存在不影响硒（IV）的去除；而碳酸盐（10 mM）、硅酸盐（1 mM）和磷酸盐（0.1 mM）会通过竞争吸附位点降低吸附效率。腐殖酸和藻酸盐（高达6 mg/L）对硒（IV）的去除没有明显影响。MNP@赤铁矿颗粒能够在10分钟内非常高效地同时去除痕量水平的硒（IV）和锑（III）。磁性吸附剂可在10 mM NaOH中轻松回收并再生15分钟。在连续五个循环中，吸附和解吸效率分别超过97%和82%。MNP@赤铁矿可作为从水中去除硒（IV）的有效吸附剂。
