Annexing Marginal Soils for Agricultural Cultivation Using an Organic Source of Fertilizer as a Bioremediation Treatment Option

摘要

This study was carried out to ascertain the practicability of using bioremedi-ated, engine-oil-impacted soil for crop cultivation. In this study, bioremediation by land farming and nutrient enhancement was used to treat contaminated soils. In the laboratory, soil samples were homogenized, analyzed, and placed into several reactor vessels including a substrate of poultry droppings and cow dung in various ratios to the contaminated soil. During the first phase of the investigation, contaminated soil without treatment served as a control. The soil matrix was homogenized on a weekly basis, and samples were drawn during the third, fifth, eighth, tenth, and fifteenth weeks for total petroleum hydrocarbon (TPH) reduction and nutrients analysis. The initial concentrations of TPH were diluted upon the addition of the poultry litter and cow dung substrate. Results obtained during the experiment indicate that the amount of nutrients generally decreased as the weeks progressed, and the TPH degradation ranged from 78.27% to 61.84% in the reactor vessels. There was no significant difference (p ＜ .05) in TPH degradation based on the substrate quantities, whereas the TPH reductions in the soil amended with the animal wastes were significantly different from the control sample (soil not amended with animal wastes). In the planting phase, uncontaminated, loamy soil was used as a control (the planting phase control), and the results show that maize planted on the treated soil germinated with no significant difference (p ＜ .05) in the number of leaves and plant heights between the treated samples and the control sample (uncontaminated loamy soil). Analysis of field-scale animal waste requirements for hypothetical TPH contaminated soil covering a certain area shows that inorganic fertilizer application requires lesser quantities with lower costs than using poultry litter and cow dung to supply nutrients to support bioreme-diation. The study concludes that bioremediation for agricultural purpose is feasible, but it can be better implemented if the astronomical quantities of substrates required for field-scale utilization can be surmounted.