REMOVAL OF DIAZINON FROM AQUEOUS SOLUTION USING AVOCADO SEED BIOCHAR

Abstract

ABSTRACT: Pollution of water bodies by pesticides and biomass wastes is increasing as Ethiopia becomes industrialised. The conventional methods of cleaning wastewater are expensive. They include ion exchange, bio sorption, solvent extraction, precipitation among others. New and cheaper technologies are emerging that utilizes locally available biomass in form of activated carbon. The aim of this study was to determine the best carbonization and activation conditions of temperature, time and phosphoric acid concentration using avocado seed wastes for removal of pesticides from wastewater. The adsorption studies were done using batch experiments by investigating the effect of initial concentration, contact time, adsorbent mass and pH. The data obtained from optimization of conditions were found to be 400 ºC, 2 hours and 85 % H3PO4 acid for maximum adsorption of diazinon using 15 mg/l solutions. The data obtained from adsorption studies for the adsorbents was found to fit best into Freundlich isotherm with R2 value of 0.967 and adsorption capacities of 90.53%. Thus maximizing activation conditions would produce a better activated carbon from avocado seeds that would be used to remove pesticides from aqueous solutions and other industrial or domestic applications. It also eliminates the problem of agricultural wastes accumulating in our environment.