BIOCHAR-MEDIATED REMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN WASHING EFFLUENT FROM AUTOMOBILE SERVICE STATION SOIL

Abstract

Petroleum hydrocarbon contamination resulting from human activities including spills, industrial manufacturing, and fossil fuel disposal is a global environmental issue. Considering the contamination of soils by petroleum oil, it has been discovered of a major challenge to the environment. The surge in the automobile industry has increased automobile service stations, especially in developing countries. As per the studies, it was revealed that service stations often discharge wastewater containing over 600 mg/L of oil and grease, contributing to soil contamination. One of the hazardous pollutants of huge concern is Polycyclic Aromatic Hydrocarbons (PAHs), known for their persistence, hydrophobicity, and ability to accumulate in the environment. PAHs, characterized by their molecular structure comprising two to six conjugated aromatic rings, pose significant health risks and have gained increasing attention from the scientific community. The US Environmental Protection Agency (EPA) has identified 16 PAHs as priority contaminants with potential carcinogenic effects, including pyrene (PYR). Pyrene is a dominant PAH resulting from incomplete combustion of oil and its byproducts, often found in soil due to its low degradability and volatility. The EPA has recommended a PYR concentration in drinking water of less than 0.2 µg/L. Particularly, PAHs may negatively impact the flora and fauna of impacted environments, leading to their uptake and accumulation in the food chain and, in certain circumstances, to severe health issues and genetic changes in people. Various cleanup techniques have been developed to address the growing concern of PAH contamination. Sorption-based methods are gaining popularity due to their nonflammability, chemical inertness, cost-effectiveness, and widespread availability. Among these methods, the use of biochar or carbon-based materials has emerged as a promising approach to remove industrial chemicals, including PAHs like naphthalene, phenanthrene, and pyrene. Although biochar has primarily been used as a soil amendment to enhance soil fertility, its potential as an innovative tool for cleaning up contaminated sites has garnered increased interest in recent years. The excellent affinity of biochar for organic contaminants like PAHs makes it attractive for soil remediation. However, despite numerous studies investigating the use of biochar, particularly from various sources, for oil spill cleanup, no research has been conducted on the use of waste-derived dendro biochar for the removal of oil from contaminated soil. Dendro biochar is formed from Gliricidia sepium and is a byproduct of dendro power industries. Previous studies have shown that biochar produced at high temperatures such as as 500 0C, removes PAHs efficiently. [2]. The focus of this research is on investigating soil contamination in automobile service stations, with particular attention to detecting the presence of PYR, a representative PAH, in the contaminated soil. Additionally, the study aims to assess the potential of dendro biochar as a treatment agent for the wastewater effluents discharged from these service stations