The effectiveness of cow manure in remediation of top soil contaminated by engine oil waste

Engine oil waste discharged into the soil can lead to serious contamination, affecting soil health and ecosystem function. Bioremediation offers an effective solution to restore soil quality by utilizing microorganisms to degrade pollutants. Cow manure, rich in beneficial microbes and nutrients, serves as both a bioactivator and a nutrient source that supports microbial activity in degrading Total Petroleum Hydrocarbons (TPH) from engine oil-contaminated soil. This study investigated the effectiveness of cow manure in the bioremediation process using six treatment variations with cow dung concentrations of 0 g, 20 g, 40 g, 60 g, 80 g, and 100 g, each mixed with 300 g of contaminated soil over a 30-day period. The results demonstrated that the treatment with 100 g of cow manure reduced TPH levels from 3.6 % to 0.2 %, achieving a degradation efficiency of 86.66 % within 30 days. Statistical analysis using a simple linear regression test confirmed that both composting time and cow dung concentration significantly influenced the reduction of TPH levels in the soil.