Selective and efficient sequestration of phosphate from waters using reusable nano-Zr(IV) oxide impregnated agricultural residue anion exchanger

• Published in: The Science of the total environment 2020-01, Vol.700, p.134999-134999, Article 134999
• Main Authors: Hu, Yu, Du, Yan, Nie, Guangze, Zhu, Tianjiao, Ding, Zhuhong, Wang, Hailing, Zhang, Lu, Xu, Yongbing
• Format: Article
• Language: English
• Subjects: adsorbents; adsorption; Agricultural residue; agricultural wastes; corn; desorption; electrostatic interactions; environment; magnesium ammonium phosphate; Nanocomposite; nanocomposites; nanomaterials; Phosphate removal; phosphorus; pollution; quaternary ammonium compounds; skeleton; synergism; wastewater; Zr(IV) oxide
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.134999

[Display omitted] •Nanocomposite Zr@MCS was fabricated by the low-cost method.•Zr@MCS exhibits selective and efficient for phosphate removal.•Saturated Zr@MCS could be effectively regenerated for sustainably utilized.•Zr@MCS has superior application capability in the fixed-bed flow system. There is an urgent need to develop low-cost and effective adsorbents for enhanced removal of phosphate from contaminated waters. In this study, nanosized Zr(IV) oxide particles were immobilized on the amino modified corn staw (MCS) to fabricate a novel nanocomposite (Zr@MCS) with superior application capability. Compared with the widely used commercial anion exchangers in previous studies, the modified agricultural residue was empolyed as the host to avoid the high costs and secondary pollution in the preparation. Zr@MCS displayed remarkable selective removal of phosphate from water even in the presence of coexisting anions (Cl−, SO42−, NO3−) at high levels, as well as with a high adsorption capacity, fast adsorption kinetics and high availability in the wide range of pH 2–8 toward phosphate. The excellent adsorption performance of Zr@MCS is attributed to the synergistic effect of the electrostatic attraction of the quaternary ammonium groups fixed on the host skeleton and the specific adsorption of phosphate derived from the hydroxyl functional groups of Zr(IV) oxide. The exhausted Zr@MCS can be effectively regenerated by 5% NaOH–NaCl solution for sustainably utilized, and phosphorus in the desorption effluent could be recovered as high-quality struvite by a simple struvite recovery process. Furthermore, the considerable treatment volume for the synthetic solution and real wastewater in a fixed-bed flow system indicated that Zr@MCS is of great potential for phosphate removal in practice.