BIOREMEDIATION OF CRUDE OIL CONTAMINATED WASTEWATER USING FLOATING TREATMENT WETLANDS

Abstract

Crude oil contaminated wastewater from hydrocarbons exploration, production and processing facilities is a serious environmental concern. Its treatment is very necessary at source level to avoid water, soil and atmospheric pollution. Bioremediation is an economical method for the wastewater contaminated by crude oil. In the current study, we developed Floating Treatment Wetlands (FTWs) in a crude oil contaminated wastewater Pit of Dakhni Oil and Gas Processing Facility in Jand, District Attock, Pakistan. Phragmites australis (Common reed) plants were grown at floating mats of locally available jambolan material with holes. Consortium of hydrocarbon-degrading bacteria and plants were used to treat the wastewater in the pit. Surface sterilization was performed for bacterial isolation from the interior of shoots and roots. Hydrocarbon contents were quantified in water samples with the help of Spectrum Two Environmental Hydrocarbons Analysis System. After FTWs bioremediation, biochemical oxygen demand, chemical oxygen demand, chlorides, hydrocarbons content, total dissolved solids, cadmium, iron and lead were reduced by 91%, 95.5%, 96%, 99.6%, 82%, 84.6%, 99.4% and 94.8% respectively in 06 months. Plant showed good growth and biomass production. Moreover, the process of bioremediation enhanced by plant-bacteria partnership developed in the shoots, roots and rhizoplane of plants. It is concluded that FTWs are economical and sustainable method of bioremediation for crude oil contaminated wastewater.