Abstract

Background and Objective: Crude oil pollution is a serious issue in Nigeria. There is, therefore, a need to source an affordable method that is eco-friendly for remediating these polluted soils. The study investigated the use of cassava peel waste as a bio stimulating agent in an in situ bioremediation of crude oil polluted site. Materials and Methods: Treatments were as follows, H1: Polluted soil with no bio-stimulation (Control), H2: Polluted soil bio-stimulated with 500 g cassava peel, H3: Polluted soil bio-stimulated with 1000 g cassava peel and H4: No pollution, no bio-stimulation (double control). Soil pH, electrical conductivity, moisture content, nitrogen, phosphorus, total organic matter, total organic carbon, potassium, total petroleum hydrocarbon, total hydrocarbon content and microbial population in soil were monitored at 0, 2 and 4 months. Results: Results showed that the percentage reduction of THC and TPH in the soil after 4 months were as follows, H2 (90.48 and 81.39%), H3 (80.19 and 63.81%) and H1 (32.90 and 14.76%), respectively. Soil properties improved with a concurrent increase in the microbial population in the bio-stimulated soil as compared to the control. Conclusion: This result proves that cassava peel waste is an effective bio-stimulating agent in crude oil degradation especially at 500 g m3 compared to other treatment options hence providing an alternative for the remediation of crude oil-polluted soil, especially in the Niger Delta part of Nigeria.