Adsorption of Glyphosate and Glufosinate by Ni_2AlNO_3 layered double hydroxide

摘要

The removal of organophosphate and organophosphonate herbicides from aqueous solution by Ni_2Al LDH material was investigated. Batch adsorption studies were conducted to evaluate the effect of various parameters such as contact time and initial herbicides concentrations. The adsorption kinetics was tested for Elovich, intraparticle diffusion, pseudo-second-order, and pseudo-first-order reactions and rate constants of kinetic models were calculated. The equilibrium adsorption data were analysed by Freundlich, Langmuir, and Tempkin using linear regression technique. Langmuir isotherms best fitted the data for adsorption equilibrium for both herbicides. Structural and textural analysis (XRD, FTIR, MEB) of Ni_2AlNO_3 LDH at different rates of adsorption evidence a mechanism of adsorption via an anion exchange reaction, Glyphosate and Glufosinate being adsorbed, in a 1rst step, at the surface of the cristallites and then intercalated in the interlayer domains.