Studies on preparation regulated by Mn2+ and phosphate adsorption of ZnO,ZnMn-LDHs

Abstract

The discharge of phosphorus-containing wastewater has led to eutrophication of water bodies, ultimately resulting in the deterioration of regional water quality. To effectively remove phosphates from water, ZnO and layered zinc-manganese hydroxide (ZnMn-LDHs) nano-adsorption materials were synthesized using zinc nitrate and manganese nitrate as raw materials and triethanolamine/water as the solvent system by hydrothermal method. The nano-materials were characterized by SEM, XRD, Zeta potentiometer, and FT-IR. The removal performance of nano-adsorption materials for phosphates was investigated. The results showed that the ratio of nZn to nMn was the main factor affecting the transformation of ZnMn-LDHs to ZnO nano-materials. The adsorption of phosphate by ZnO and ZnMn-LDHs both conformed to the Freundlich isothermal adsorption model and pseudo-second-order kinetic model. Under the same conditions, the adsorption performance of ZnMn-LDHs for phosphate was better than that of ZnO. The regeneration of the materials could be achieved through desorption with 0.01 mol/L NaOH. After six cycles of utilization, the removal rates of phosphate by ZnO and ZnMn-LDHs could still reach over 80%.

Keywords

• zno
• znmn-ldhs
• phosphate radical
• recycling