Department of Chemistry, Mississippi State University, Starkville, MS 39762, United States.
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
Bioresour Technol. 2018 Sep;263:258-265. doi: 10.1016/j.biortech.2018.05.001. Epub 2018 May 2.
α-FeO and FeO dispersed on high surface area (663 m/g) Douglas fir biochar (BC) was prepared for fast nitrate and fluoride ion removal from water using magnetic separations. This biochar, made originally at 900 °C, was impregnated with FeCl and converted by pyrolysis at 600 °C to magnetic (494 m/g) biochar (MBC). MBC and its precursor BC were characterized using SEM, SEM-EDX, STEM, S, PZC measurements, XRD analysis, and XPS. Dispersed α-FeO and FeO particles caused magnetization and generated most adsorption sites, causing more nitrate and fluoride uptake than BC. Both nitrate and fluoride adsorption on MBC remained high over a pH range from 2 to 10. Sorption was evaluated from 298 to 318 K using the Langmuir and Freundlich isotherm models. Langmuir adsorption capacities were 15 mg/g for nitrate and 9 mg/g for fluoride, higher capacities than those reported for other biochar and iron oxide adsorbents.
α-FeO 和 FeO 分散在高表面积（663 m/g）的花旗松生物炭（BC）上，用于通过磁分离从水中快速去除硝酸盐和氟离子。这种生物炭最初是在 900°C 下制备的，用 FeCl 浸渍，并在 600°C 下通过热解转化为磁性（494 m/g）生物炭（MBC）。使用 SEM、SEM-EDX、STEM、S、PZC 测量、XRD 分析和 XPS 对 MBC 及其前体 BC 进行了表征。分散的 α-FeO 和 FeO 颗粒引起磁化并产生了大多数吸附位点，导致比 BC 更多的硝酸盐和氟化物被吸收。MBC 对硝酸盐和氟化物的吸附在 pH 值为 2 至 10 的范围内均保持较高水平。使用 Langmuir 和 Freundlich 等温线模型从 298 到 318 K 评估了吸附。硝酸盐的 Langmuir 吸附容量为 15 mg/g，氟化物的吸附容量为 9 mg/g，高于其他生物炭和氧化铁吸附剂的报道容量。
