Evaluation of phytoremediation effects of chicken manure, urea and lemongrass on remediating a lead contaminated soil in Kabwe, Zambia

Abstract

High levels of lead (Pb) in the soil is a serious issue in the city of Kabwe, Zambia. Phytoremediation is an effective approach to revive the life-supporting functions of the soils. Locally available soil amendments, such as chicken manure, can strengthen phytoremediation. This study aims to find an appropriate combination of a locally available Pb hyperaccumulator, lemongrass (Cymbopogon citratus (DC.) Stapf.), and soil amendments, to minimize the Pb pollution. After a short-term (78 day) pot experiment with lemongrass and three soil amendments (chicken manure, biochar of chicken manure, and urea) on a Pb-contaminated soil in Kabwe, an edible crop, dent corn (Zea mays var. indentata (Sturtev.) L.H.Bailey), was grown for two weeks. Chicken manure combined with lemongrass had the most beneficial impact, reducing the Pb level in dent corn by 19%, compared to the Pb in dent corn grown on the control soil. By growing lemongrass in the Kabwe soil with chicken manure, the exchangeable soil Pb was reduced by 70%. The growth of lemongrass without chicken manure reduced the exchangeable soil Pb by 20%. In conclusion, lemongrass successfully reduced Pb levels, in combination with chicken manure. Soil amendments must be chosen carefully by considering the soil properties and environmental conditions for an optimized Pb reduction.