Removal of Pesticides from Iraqi Soils and Water

Abstract

Contamination of soil and water with various types of pesticides, resulting from accidental spills at agrochemical manufacturing, formulation, and distribution facilities, farm loading/washdown sites, or abandoned waste sites, is a serious environmental problem in many places in the world. The remediation of two types of pesticides which were (carbofuran and chlorpyrifos) from three types of Iraqi soils (sandy, silty and clayey) was investigated in the present study. The treatment process was performed through washing method using distilled water in batch mode then; a continuous fixed bed unit was used to perform the removal of the same two types of pesticides from wasted washing polluted water using adsorption technique at different operating conditions with low-cost adsorbents which were watermelon peel (WP) and used tea leaves (UTL). The results show that the maximum removal efficiencies of pesticide from polluted soils were 81.268, 99.531 and 89.151 for clayey, sandy and silty soils respectively for carbofuran and 77.420, 94.790 and 85.481 for clayey, sandy and silty soils respectively for chlorpyrifos. Adsorption isotherm and kinetic models have been used to fit the experimental data. Finally, in this study a novel way was suggested and experimented as a safe, economic, beneficial and eco-friendly non-conventional method to get rid of the WP and UTL loaded with carbofuran and chlorpyrifos pesticides wasted. This method was trying to convert these toxic residues to applicable useful material like rodenticide. The results show that good ability for these residue to be an active rodenticide through the LD₅₀ calculated.