Environment Functional Materials Division, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Liaoning Province, Shenyang 110016, PR China.
Water Res. 2013 Oct 15;47(16):6258-68. doi: 10.1016/j.watres.2013.07.040. Epub 2013 Aug 13.
Highly porous, nanostructured zirconium oxide spheres were fabricated from ZrO2 nanoparticles with the assistance of agar powder to form spheres with size at millimeter level followed with a heat treatment at 450 °C to remove agar network, which provided a simple, low-cost, and safe process for the synthesis of ZrO2 spheres. These ZrO2 spheres had a dual-pore structure, in which interconnected macropores were beneficial for liquid transport and the mesopores could largely increase their surface area (about 98 m(2)/g) for effective contact with arsenic species in water. These ZrO2 spheres demonstrated an even better arsenic removal performance on both As(III) and As(V) than ZrO2 nanoparticles, and could be readily applied to commonly used fixed-bed adsorption reactors in the industry. A short bed adsorbent test was conducted to validate the calculated external mass transport coefficient and the pore diffusion coefficient. The performance of full-scale fixed bed systems with these ZrO2 spheres as the adsorber was estimated by the validated pore surface diffusion modeling. With the empty bed contact time (EBCT) at 10 min and the initial arsenic concentration at 30 ppb, the number of bed volumes that could be treated by these dry ZrO2 spheres reached ~255,000 BVs and ~271,000 BVs for As(III) and As(V), respectively, until the maximum contaminant level of 10 ppb was reached. These ZrO2 spheres are non-toxic, highly stable, and resistant to acid and alkali, have a high arsenic adsorption capacity, and could be easily adapted for various arsenic removal apparatus. Thus, these ZrO2 spheres may have a promising potential for their application in water treatment practice.
高度多孔、纳米结构的氧化锆球体是由 ZrO2 纳米粒子在琼脂粉末的辅助下制备而成的，这些纳米粒子形成了毫米级大小的球体，随后在 450°C 下进行热处理以去除琼脂网络，从而提供了一种简单、低成本且安全的合成 ZrO2 球体的方法。这些 ZrO2 球体具有双孔结构，其中相互连通的大孔有利于液体传输，介孔可以大大增加其表面积（约 98 m2/g），从而有效地与水中的砷物种接触。这些 ZrO2 球体对 As(III)和 As(V)的去除性能均优于 ZrO2 纳米粒子，并且可以很容易地应用于工业中常用的固定床吸附反应器。进行了短床吸附剂测试以验证计算得到的外部传质系数和孔扩散系数。通过验证的孔表面扩散模型来评估这些 ZrO2 球体作为吸附剂的全规模固定床系统的性能。在空床接触时间（EBCT）为 10 分钟且初始砷浓度为 30 ppb 的条件下，这些干燥的 ZrO2 球体可以处理的床体积数分别达到约 255,000 BV 和约 271,000 BV，用于去除 As(III)和 As(V)，直到达到 10 ppb 的最大污染物水平。这些 ZrO2 球体无毒、高度稳定、耐酸耐碱、具有高的砷吸附容量，并且易于适应各种砷去除装置。因此，这些 ZrO2 球体在水处理实践中可能具有广阔的应用前景。
