摘要：

为去除工业废水中较低浓度的氟离子，通过一步浸渍法合成了一种椰壳活性炭负载氧化铈的新型吸附剂（CeO₂-C），并对其制备工艺进行了优化，得到最佳制备工艺条件为Ce³⁺浓度0.1 mol/L、n（H₂O₂）/n（Ce³⁺）=0.5、负载时间10 h、负载固液比（椰壳活性炭载体质量与含铈的负载溶液体积之比）0.1 g/mL。表征结果表明，负载后铈元素均匀分布于椰壳活性炭表面并堵塞其部分孔洞，致使椰壳活性炭的比表面积、孔径、孔体积均略有减少。以优化条件下制备的CeO₂-C吸附剂去除水中质量浓度为10 mg/L的氟离子，结果表明，在最佳除氟条件，即pH=2，吸附固液比（吸附剂质量与模拟含氟溶液体积之比）为30 g/L，吸附时间为90 min条件下，氟离子质量浓度可降至0.18 mg/L，去除率达98.2%。机理研究表明，吸附过程符合Langmuir等温模型（R²>0.99），吸附机制主要为氟离子与羟基（OH⁻）的离子交换作用。

关键词: 除氟, 吸附剂, 氧化铈, 活性炭

Abstract:

To remove low concentrations of fluoride ions from industrial wastewater, a novel adsorbent(CeO₂-C) of coconut shell activated carbon loaded with cerium oxide was synthesized by one-step impregnation method, and its preparation process was optimized. The optimal preparation conditions were obtained as Ce³⁺ concentration of 0.1 mol/L, n(H₂O₂)/n(Ce³⁺)=0.5, loading time of 10 h, and loading solid-liquid ratio (the ratio of the mass of coconut shell activated carbon carrier to the volume of cerium-containing loading solution) of 0.1 g/mL. The characterization results indicated that cerium element was uniformly distributed on the surface of coconut shell activated carbon and blocked some of its pores, resulting in a slight decrease in the specific surface area, pore size, and pore volume of coconut shell activated carbon. The CeO₂-C adsorbent prepared under optimized conditions was used to remove fluoride ions with a mass concentration of 10 mg/L in water. The results showed that under optimal fluoride removal conditions of pH=2, adsorption solid-liquid ratio (ratio of adsorbent mass to simulated fluorine-containing solution volume) of 30 g/L, and adsorption time of 90 min, the mass concentration of fluoride ions decreased to 0.18 mg/L, and the removal rate reached as high as 98.2%. Mechanism studies showed that the adsorption process conformed the Langmuir isotherm model (R²>0.99), and the adsorption mechanism was mainly the ion exchange between fluoride ions and hydroxyl groups (OH^-).

Key words: fluoride removal, adsorbent, cerium oxide, activated carbon

中图分类号: 

• TQ124.3