Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.
School of Environmental science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, China.
Environ Sci Pollut Res Int. 2019 Jun;26(17):17373-17382. doi: 10.1007/s11356-019-04914-8. Epub 2019 Apr 24.
In this study, a novel Fe-Mn-Ce oxide-modified biochar composite (FMCBC) was synthesized via pyrolysis to enhance the adsorption capacity of biochar (BC). Scanning electron microscopy-energy-dispersive X-ray spectroscopy confirmed that Fe, Mn, and Ce were successfully loaded onto the surface of the BC. A series of adsorption experiments showed that the FMCBC exhibited improved adsorption of As(III) in an aqueous environment. The adsorption process was well expressed by the pseudo-second-order kinetic model. The adsorption capacity of FMCBC reached 8.74 mg L, which was 3.27 times greater than that of BC. The pH of the solution significantly influenced the adsorption of As(III), where the amount of As(III) adsorbed by FMCBC was maximized at pH 3. A high phosphate concentration inhibited adsorption, whereas nitrate and sulfate ions promoted As(III) adsorption and increased the FMCBC adsorption capacity. Similarly, with increasing humic acid concentration, the adsorption capacity of FMCBC for As(III) decreased; however, a low concentration of humic acid promoted adsorption. X-ray photoelectron spectroscopy analysis revealed that the adsorption of As(III) by FMCBC occurred through redox and surface complexation reactions. Therefore, FMCBC has excellent potential for purifying arsenic-contaminated water.
在这项研究中，通过热解合成了一种新型的 Fe-Mn-Ce 氧化物修饰生物炭复合材料（FMCBC），以提高生物炭（BC）的吸附能力。扫描电子显微镜-能谱分析证实，Fe、Mn 和 Ce 成功负载到 BC 的表面上。一系列吸附实验表明，FMCBC 表现出了在水相中对 As(III)的增强吸附能力。吸附过程很好地符合准二级动力学模型。FMCBC 的吸附容量达到 8.74mg/L，是 BC 的 3.27 倍。溶液的 pH 值对 As(III)的吸附有显著影响，在 pH 值为 3 时，FMCBC 对 As(III)的吸附量最大。高浓度的磷酸盐会抑制吸附，而硝酸盐和硫酸盐离子会促进 As(III)的吸附并增加 FMCBC 的吸附容量。同样地，随着腐殖酸浓度的增加，FMCBC 对 As(III)的吸附容量降低；然而，低浓度的腐殖酸会促进吸附。X 射线光电子能谱分析表明，FMCBC 对 As(III)的吸附是通过氧化还原和表面络合反应发生的。因此，FMCBC 具有净化含砷污染水的巨大潜力。
