Phenol Transport and Biodegradation Model in an Unsaturated Porous Media from Wastewater Discharge

Abstract

To minimize groundwater pollution and suggest appropriate remedial actions, sound numerical models must be developed to predict the fate, transport and biodegradation of pollutants in partially treated or untreated industrial wastewater. Phenol is an aromatic organic compound produced on a large scale and is also released as major organic pollutant from several industrial wastewater (pharmaceutical, petroleum, coal refineries etc.,). Biodegradation of phenol in soil is generally rapid especially in presence of nutrients and acclimated microbes which are discharged along with the partially treated wastewater. A numerical model has been developed to predict the fate of phenol from industrial wastewater discharged on to a porous unsaturated soil media. The transport processes of advection, dispersion, and biodegradation process using Haldane growth and inhibition have been incorporated in the numerical model. The results suggest that acclimated microbes in the wastewater has a potential to degrade phenol up to 1500 mg/L at a bacterial concentration of 0.1 mg/L and soil depth of 50 cm. The results also show that phenols desorb at a depth of 100cm from 12th day and are simultaneously acted upon by the increased microbial concentration. In essence, high microbial concentration significantly decreases the phenol movement in the unsaturated zone, particularly at a larger depth and at higher time levels which eventually affects the groundwater quality.