PHOSPHORUS REMOVAL PERFORMANCE AND MECHANISM IN WATER OF ZINC IRON HYDROTALCITE MODIFIED RED MUD
To solve the problem of excessive phosphorus in water,Zn/Fe-LDHs modified red mud(ZFRM)was prepared by coprecipitating Zn/Fe-LDHs onto the surface of red mud(RM)under alkaline conditions,and used to remove phosphate from wastewater.The phosphate removal performance and mechanism of Zn/Fe-LDHs modified red mud were studied by kinetic experiments,thermodynamic experiments,and regeneration experiments,combined with SEM,BET,XRD,and FTIR characterization.The results showed that the adsorption process of ZFRM to phosphorus conformed to the quasi-second-order kinetic model and Langmuir adsorption isotherm model.At 45 ℃,the maximum adsorption capacity was 56.26 mg/g,and the adsorption reaction was spontaneous and entropy-increasing endothermic reaction.The phosphorus removal capacity of ZFRM was less affected by pH.Carbonate ions coexisting in water can inhibit phosphorus adsorption.In the regeneration experiment,the adsorption capacity of ZFRM after 4 regenerations was 19.07 mg/g,and still had good adsorption performance.In addition,lamellar zinc iron hydrotalcite had been successfully coated on the surface of the flocculent red mud,forming a developed pore structure,and significantly increasing the specific surface area.The adsorption mechanism mainly included ion exchange,coordination reaction,and electrostatic action.Compared with other phosphorus removal materials,the synthesized ZFRM had high phosphorus removal efficiency,strong reproducibility,cheap raw materials,and simple synthesis process.It was a highly effective phosphorus removal agent with great potential in application.
NETL
NSTL
万方数据
