Kinetics of Bioremediation of Crude Oil Polluted Soil Using a Blend of NPK Fertilizer and Periwinkle Shell Ash

Abstract

In this study, we investigated the bioremediation of crude oil-polluted soil using a combination of NPK (15-15-15) fertilizer and Periwinkle Shell Ash (PSA). The experiment involved seven batch bioreactors operating under aerobic conditions. Each bioreactor contained 2 kg of soil sample spiked with 200 ml of crude oil (except for the control). Throughout the 90-day experimentation period, the soil samples were thoroughly mixed and periodically tilled. We analyzed the substrate concentration in terms of Total Petroleum Hydrocarbon (TPH) and monitored soil pH. Additionally, soil parameters (nitrogen, organic compounds, phosphorus, and potassium) were measured at the beginning and end of the experiments. Notably, TPH values decreased from 58,200 mg/kg to 34,591 mg/kg in the control group and reached a minimum of 18,045 mg/kg in the sample treated with 100 g NPK and 500 g PSA. The pH values ranged from 5.7 to 8.8 across all samples during the experimentation. Overall, the results indicate a 69% degradation in the sample treated with 100 g NPK and 500 g PSA, while using only 500 g of PSA as an amendment resulted in 67.97% degradation.

Keywords — Bioreactors, Biodegradation, Monod growth kinetics, substrate concentration, Total

Heterotrophic Bacteria