Bioremediation of Soil Samples Contaminated with Crude Oil using Rice Husk-based Biocarbon (Oryza Sativa)

Abstract

This research consisted of the bioremediation of four soil samples contaminated with oil using biochar made from rice husks. For this, fourth samples of soil Balao (B), Tachina (T), Refinería (R), and Winchele (W), from the province of Esmeraldas, Ecuador, previously contaminated with oil from a refinery in the country. The rice husk (Oryza sativa) was characterized to determine its ash, organic matter, and moisture content. The soil samples were characterized to know their cation exchange capacity, pH, temperature, humidity, organic carbon, ash, organic matter, density, porosity, and texture. The crude oil used as a soil contaminant agent was determined by API, temperature, Conradson carbon, density, ash, organic matter, and viscosity of the crude oil. Each sample was contaminated, and the bioremediation process was evaluated for 90 days. In the zero analysis, the content of total hydrocarbons (TPH) in sample B was 2,691.78 mg/Kg, 2,505.99 mg/Kg for T, 2,950.99 mg/Kg in R and W with 2,708.24 mg /Kg. Once the biochar was obtained, its pH, initial yield, density, ash content, organic matter, phosphorus, calcium, and magnesium were known. After bioremediation, concentrations of 475.61mg/Kg, 209.65mg/Kg, 136.66mg/Kg, and 578.05mg/Kg of TPHs were reached for B, T, R, and B, achieving compliance with the permissible limit established in local legislation for contaminated soils. The results obtained indicate that the process used can be an alternative to soil bioremediation processes.