Monitoring the <i>in-situ</i> Bioremediation of Spend engine-oil contaminated soil After Irrigation with Fermented Chicken-droppings

Abstract

Preparation for the bioremediation of petroleum contaminants is explored to provide a low-cost and capable strategy for biodegradation of  contaminants and renewal of soil fertility. In this study, fermented chicken droppings were used as novel in-situ bio-stimulants and bio- augmentation materials. The investigation determines the capability of fermented chicken droppings to biodegrade the residual total petroleum  hydrocarbon compounds in-used engine oil contaminated soil – in the case of auto mechanic shops. The soil was collected at 10 cm depth from the ground, air-dried and sieved with 2.5mm mesh. A 4 kg of soil was weighed into 13 perforated buckets to allow aeration and prevent waterlogging. The setup consists of three replicates that were spiked with 150 ml of used engine oil. 500 ml of the fermented chicken droppings were used to irrigate the contaminated soil at ratio 1:8 periodically for every 3 days per irrigation for 21 days. The uncontaminated soil used as the control group was irrigated with normal water. The TPH composition of the contaminated and remediated soil samples was screened using gas Chromatography tandem mass spectroscopy. Results show that the uncontaminated soil (A-group) had C10 - 24.058 ± 0.02 ppm, C12 - 37.327 ± 0.01 ppm, C14 - 28.515 ± 0.02 ppm and C16 - 12.097 ± 0.02 ppm, respectively out of about 35 TPH compounds that ought to be detected from C8 to C40. The Concentration of TPH in Contaminated soil before irrigation with Chicken droppings – positive control (ppm) B-group gave a significant qualitative and quantitative presence of TPHs in contaminated soil at varying concentrations. 36 TPHs were detected out of forty, starting from C10 - 1.836 ± 0.01 ppm to C38 -  50.150±0.01 ppm. Whereas, the Concentration of residual TPH in Contaminated soil after irrigation with Chicken droppings gave varying levels of residual TPHs ranging from C8 - 1.519 ± 0.02 ppm to C38 - 41.487 ±0.02 ppm. This also gave a resultant/differences in the degradation level of TPHs. Differences in TPH Concentration between before the irrigation and after irrigation of contaminated soil were calculated, C8 had - 0.317 ppm while another TPHs concentration varies accordingly. From the results, one can be deduced that despite other environmental factors that influence the degradation of TPHs, fermented chicken droppings showed great capability in the degradation of TPHs in the contaminated soil.

Keywords: Bioremediation, auto-mechanic-yard, Soil-fertility, Used-engine-oil, fermented-chicken-droppings