Highly selective and efficient removal of phosphate by La(OH)3-loaded Juncus effusus with a three-dimensional structure

ABSTRACT In this study, La(OH) 3 -loaded Juncus effusus (La-JE) with a three-dimensional structure was prepared via an in-situ precipitation and then wrapped in a cellulose membrane. The La-JE not only avoided the leakage of La(OH) 3 but also was separated from solution easily. The optimal pH for phosphate removal by the La-JE was 6. The removal rate of phosphate was positively correlated with adsorption time, La-JE dosage and reaction temperature, and negatively correlated with phosphate concentration. The adsorption process conformed to pseudo-second-order kinetic model and was better fit by Freundlich model. At 25°C, the maximum adsorption capacity of the La-JE was 22.75 mg·P/g. The influence of SO 4 2– , Cl – , NO 3 – , NH 4 + , HCO 3 – and CO 3 2– on phosphate removal was negligible, suggesting that the La-JE had good anti-interference ability. Mechanism analysis showed that the removal process of phosphate was related to both ligand exchange and surface precipitation. The application in real water environment exhibited that the La-JE had good potential for advanced dephosphorization of sewage treatment plant and natural waterbody remediation.