Heavy Metals Bioremediation of Agricultural Soil Using Poultry Litter

The aim of this research is to determine the level of heavy metals contamination of agricultural soil and to reduce its concentration in the soil using poultry litter. Soil sampled at Inua Eyet Ikot, Mkpanak, Ibeno Local Government Area of Akwa Ibom State was analyzed to check for the initial heavy metal concentration of the soil. Poultry litter as a nutrient additive bearing microorganisms, bacteria, and fungi was introduced to the soil to reduce the concentration of heavy metals. The sampled soil was mixed with poultry litter at three different proportions i.e. poultry litter (PL) to crude oil contaminated soil (COCS) namely PL 20% + COCS, PL 40% + COCS and PL 50% + COCS. Heavy metals Copper(Cu), Iron (Fe), Manganese (Mn), Lead (Pb), Cadmium (Cd), Arsenic (As), Chromium (Cr), Nickel (Ni) concentration in the soil before and after 8 weeks were measured and analyzed by Atomic Absorption Spectrophotometer (AAS) analysis which was carried out using wet oxidation method (digestion) for soils. The treatment category PL 50% + COCS proved to be more effective in the reduction of heavy metals in the soil as it reduced Copper, Iron, Manganese, Lead, Cadmium, Arsenic, Chromium and Nickel by 87.5%, 92.2%, 93.37%, 49.72%, 67%, 66.8%, 76.1% and 73.7%. Reductions in all treatment categories were statistically analyzed by Analysis of Variance (ANOVA) and were found to be significantly different from the untreated soil at probability value P<0.05, with the significance level at 95%. The research findings indicate that poultry litter, which has microorganisms in it, enhances reduction of the concentration of heavy metals in contaminated soils.