[Adsorption of Residual Pesticide Glyphosate Isopropylamine in Surface Water by Modified Biomass Materials].

Abstract

Effective treatment of pesticide residue-induced pollution in the aqueous environment is the key to improving the water quality of rivers and lakes. Modified biomass material (Fe-Al-PS) was successfully prepared by impregnating Fe and Al bimetallic compounds to peanut shell powder for adsorption of glyphosate isopropylamine salt herbicide residues in aqueous environments. Fe-Al-PS reached adsorption equilibrium for 10 mg·L^-1 of glyphosate isopropylamine salt at the adsorbent dosage and adsorption time of 0.14 g and 10 min, respectively, and the removal rates were stabilized at 99.9 % and 99.6 %, respectively. The adsorption process followed the pseudo-secondary kinetic and Freundlich adsorption isotherm models and belonged to multi-molecular layer chemisorption. The removal of glyphosate isopropylamine salt by Fe-Al-PS was greater than 95 % in a wide range of pH (2-11). The thermodynamic results indicated that the adsorption was a spontaneous exothermic process. Fe-Al-PS materials were easy to access and involved simple synthesis and low energy consumption, had high anti-interference ability, were reusable, and could be used not only for the effective removal of glyphosate isopropylamine salt herbicide in real water bodies but also for the removal of inorganic phosphorus.