DISPOSABLE RESIDUE OF TRADITIONALLY FERMENTED ETHIOPIAN LOCAL BEER (TELLA) FOR QUANTITATIVE UPTAKE OF PESTICIDE POLLUTANTS FROM CONTAMINATED WATERS

Abstract

This major aim of this study was centered at developing a novel analytical method that enable quantitative uptake of multiclass pesticide pollutants from contaminated aqueous solution using a biosorbent obtained as a solid residue from fermented traditional alcoholic beverage; Tella. The solid residue considered in the study, also called Local Beer Residue (LBR ) was first washed thoroughly under running water and then reagent water, and also treated with dilute hydrochloric acid solution. Presence and types of the functional groups on the LBR surface, that are facilitating analytes sorption, were analyzed using the FT-IR spectrometer, after processing to make a pellet with KBr. The effects of various experimental parameters on the biosorbent performances were studied and then optimized for maximum removal of the s-triazine family pesticides, such as atrazine, ametryn, secbumeton, propazine and prometryn. The established optimum conditions includes pH of 5.0, adsorption dose of 0.7 g, agitation speed of 250 rpm, contact time of 75 min and analytes concentration ranging within 0.25 to 1 mg/L. Furthermore, adsorptions of most analytes, considered in the study, were found to fit Langmuir adsorption model while two of them, viz., prometryn and terbutryn following the Freundlich model. The experimental adsorption results were found fit the pseudo-second order kinetic model for all the studied analytes, certifying chemisorption to be the rate-determining step. It has also been understood that the acid treated residue of LBR to exhibit efficient adsorption capacity for quantitative removal of the target analytes considered. The novel LBR biosorbent developed in this study has further displayed remarkable performances its capacity for efficient removal of pesticide pollutants from contaminated water samples and thus can be used as effective, cheap, low-cost and locally available adsobent.