School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13, Yanta Road, Beiling District, Xi'an, Shaanxi, 710055, China.
College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Environ Sci Pollut Res Int. 2018 Jun;25(16):15390-15403. doi: 10.1007/s11356-018-1711-1. Epub 2018 Mar 21.
Granular zirconium-aluminum hybrid adsorbent (GZAHA) was fabricated for efficient defluoridation of groundwater in filter application. GZAHA was formed through the aggregation of massive Zr/Al oxide nanoparticles with an amorphous pattern. This adsorbent has a satisfactory mechanical strength, a specific surface area of 29.55 m/g, and numerous hydroxyl groups on the surface. F adsorption equilibrium could be achieved within 12 h, and the sorption process followed a pseudo-second-order reaction rate. The maximum adsorption capacity of F estimated from the Langmuir model was 65.07 mg/g at 25 °C, being greater than most of other granular adsorbents. The removal efficiency of F could be maintained in a wide pH range of 5~9. The presence of phosphate posed an adverse effect on F adsorption due to the competition mechanisms. The saturated adsorbents could be regenerated and reused for four times by using sodium hydroxide solution as an eluent, and the adsorption capacity remained around 80%. Besides electrostatic attraction and Al-F complex, surface complexation and anion exchange were also involved in the adsorption process. Continuous adsorption experiments illustrated that 808 bed volumes of F-contaminated water (F = 5 mg/L) were treated successfully by a GZAHA-packed column without second pollution.
颗粒状锆铝混合吸附剂（GZAHA）被制备用于在过滤应用中高效去除地下水中的氟化物。GZAHA 通过大量 Zr/Al 氧化物纳米颗粒的聚集形成，具有无定形图案。该吸附剂具有令人满意的机械强度，比表面积为 29.55 m/g，表面有许多羟基。F 的吸附平衡可以在 12 h 内达到，吸附过程遵循伪二级反应速率。从 Langmuir 模型估计的 F 的最大吸附容量在 25°C 时为 65.07 mg/g，大于大多数其他颗粒状吸附剂。F 的去除效率可以在 5~9 的宽 pH 范围内保持。由于竞争机制，磷酸盐的存在对 F 的吸附有不利影响。饱和吸附剂可以用氢氧化钠溶液作为洗脱剂再生和重复使用四次，吸附容量保持在 80%左右。除静电吸引和 Al-F 络合外，表面络合和阴离子交换也参与了吸附过程。连续吸附实验表明，成功处理了 808 倍床体积的 F 污染水（F = 5 mg/L），使用 GZAHA 填充柱没有二次污染。
