Activation of spent coffee ground for the removal of glyphosate in aqueous solution

Abstract

Glyphosate (N-(phosphonomethyl) glycine) is one of the most widely used herbicides on agricultural land with an annual consumption is about 826 million kg in 2014, resulting in considerable amounts of water and soil pollution. Great attention has been paid to the removal of glyphosate in aqueous solution and many techniques have been developed. Among them, adsorption offers itself as a viable option for glyphosate removal and the searching of low cost adsorbent is always desired. Coffee drinking generates a massive volume of spent coffee grounds. Therefore, using spent coffee as feedstock for making adsorbent is investigated in this study. The activated carbon was prepared from spent coffee ground using chemical, Zn(CH3COO)2 and H2O2, then followed by heat treatment. The coffee grounds activated carbon was characterized by scanning electron microscope, BET Surface Area Analyzer. The effects of preparation conditions of obtained spent coffee ground powder on glyphosate removal were investigated using one variable at a time method. The adsorption tests were conducted in batch mode.