Effect of Varying E-Safe Concentrations on Physicochemical Properties and Hydrocarbon Remediation of Aged Crude Oil-Polluted Soil

Background and Objective: Crude oil contamination significantly alters the physicochemical properties of soil, posing long-term threats to soil fertility, microbial life, and food security, especially in developing countries like Nigeria.While various remediation products exist, region-specific and affordable solutions remain limited.This study aimed to evaluate the effectiveness of different concentrations of E-safe in remediating aged crude oil-impacted soil by assessing its impact on key physicochemical parameters and hydrocarbon degradation.Materials and Methods: A laboratory-based experiment was conducted using soil collected from a crude oil-contaminated site in Rivers State.The topsoil (0-30 cm) was sieved and artificially treated with five concentrations of E-safe (0, 1.5, 3, 6, and 12 mL/kg of soil) in a Completely Randomized Design.Each treatment was applied to 1 kg of soil and monitored for 8 weeks.Total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAH), pH, nitrate, and phosphate were analyzed using standard analytical procedures.Data were presented in charts and tables, with means separated using DMRT at p<0.05.Results: The E-safe significantly enhanced hydrocarbon degradation and improved soil conditions.The highest TPH degradation (98.79%) was observed at 12 mL/kg E-safe, while the control showed the least degradation (13.37%).The PAH removal ranged from 80.16% to 98.78% across treated groups.Soil pH shifted from slightly acidic to basic with increasing E-safe concentration.All E-safe treatments demonstrated over 60% improvement in degradation compared to the control. Conclusion:The E-safe effectively improved the remediation of aged oil-contaminated soils, particularly at higher concentrations.These findings support its potential use in developing countries where crude oil pollution is a persistent problem.Future studies should investigate long-term soil health and microbial recovery following E-safe application to refine optimal dosing and environmental safety.