Determination and Remediation of Selected Polycyclic Aromatic Hydrocarbons in Petroleum Contaminated Water

Abstract

Determination and remediation of pollutants such as polycyclic aromatic hydrocarbons (PAHs) have not being fully regulated in Nigeria; hence  contamination of surface water by such pollutant is a major concern. This study was designed to determine the level of selected PAHs in petroleum contaminated water using spectroscopic techniques and the efficacy of activated carbons made from Bambusa vulgaris and Oxytenanthera  vabyssinaca. Bambusa vulgaris and Oxytenanthera abyssinaca were carbonized at 350^OC and activated with Phosphoric acid (CBV350^OC H₃PO₄₎ and Potassium chloride (COA 350^OC KCl) as dehydrating agent respectively. The adsorbents were then used to remediate PAHs in petroleum contaminated water. Liquid-Liquid extraction procedures were used for extracting selected PAHs from sampled solutions. The batch experiment was performed to study the adsorption capacity of adsorbents at 5hrs contact time. Analysis of PAHs concentration for each sampling day was determined by GC-MS. Total PAHs in simulated wastewater did not show a clear trend, contrary to the expectation that there should be a progressive increase with time due to photolysis or photodecomposition of compounds or PAHs. COA 350^OC KCl showed a range of 6.2-19.3% removal efficiency of each selected PAH with a total percentage efficiency of 27.7-70.8 for all days. For CBV350^OC H₃PO₄ removal efficiency ranged from 10.26-19.30% for each selected PAH and a total efficiency of 50.8-100% for all selected PAHs for the 4 days intervals. The experimental result showed that adsorbent made from Bambusa vulgaris and Oxytenanthera abyssinaca and activated with H₃PO₄ and KCl as dehydrating agent
respectively can efficiently adsorb the selected PAHs in contaminated water. The study also revealed that PAHs in contaminated water increases with time due to photodecomposition, thus necessitating their treatment on time.