College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, China.
College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, China.
Environ Res. 2020 May;184:109309. doi: 10.1016/j.envres.2020.109309. Epub 2020 Feb 28.
Eutrophication which caused by excessive phosphorus in aquatic environment is a worldwide problem. Phosphorus is a nonrenewable resource widely used in agriculture and industry. Therefore, the development of economical methods for phosphorus capture and reuse from wastewater is urgently needed. In this study, a novel granule chitosan inlaid with γ-AlOOH on its structure (γ-AlOOH@CS) was prepared for phosphate removal with a recycle manner. Results showed that γ-AlOOH@CS exhibited a fast phosphate removal of 0.5 h for half adsorption capacity. The material presented a high adsorption capacity of 45.82 mg/g, the adsorption capacity maintained stability at pH 4-6, and favorable selectivity was observed when compared with other common anions. Column experiment was also performed well in treatment of the simulated wastewater. Isotherms and thermodynamics studies indicated that phosphate adsorption onto γ-AlOOH@CS was heterogeneous, spontaneous and exothermic. In material recycle experiment, by using NaOH solution as solvent and phosphoric acid as precipitant under hydrothermal reaction conditions, the products of chitosan, aluminum phosphate and sodium dihydrogen phosphate were obtained, with their purity reaching the industrial standard. Meanwhile, chitosan can be reused for new γ-AlOOH@CS preparation. This study provides a total recycle strategy of phosphorus removal from wastewater.
富营养化是由水体中过量的磷引起的，是一个全球性的问题。磷是一种不可再生资源，广泛应用于农业和工业。因此，迫切需要开发从废水中经济地捕获和再利用磷的方法。在本研究中，制备了一种新型的壳聚糖颗粒，其结构上镶嵌了γ-AlOOH（γ-AlOOH@CS），用于以循环方式去除磷酸盐。结果表明，γ-AlOOH@CS 对磷酸盐具有快速去除能力，半吸附容量的去除时间为 0.5 小时。该材料具有 45.82 mg/g 的高吸附容量，在 pH 4-6 范围内吸附容量稳定，与其他常见阴离子相比具有良好的选择性。柱实验也很好地处理了模拟废水。等温线和热力学研究表明，磷酸盐在γ-AlOOH@CS 上的吸附是不均匀的、自发的和放热的。在材料回收实验中，通过在水热反应条件下使用 NaOH 溶液作为溶剂和磷酸作为沉淀剂，可以得到壳聚糖、磷酸铝和磷酸二氢钠的产物，其纯度达到工业标准。同时，壳聚糖可以重复用于新的γ-AlOOH@CS 的制备。本研究为从废水中去除磷提供了一种全面的回收策略。
