Effect of Oxygen on the Adsorption of Pentachlorophenol by Peat from Water

Abstract

Pentachlorophenol (PCP), a versatile biocide has been extensively used in industry and agriculture. PCP has been designated as a priority organic pollutant by the United States Environmental Protection Agency (USEPA) and its use in consumer products has been banned since 1984. Extensive use of PCP as a wood preservative has led to soil, surface water and groundwater pollution. Batch adsorption studies using peat at various dissolved oxygen (DO) levels in water showed that higher PCP removals can be attained at elevated DO levels. This effect can be quantified by a comparison of the adsorption capacities of peat from linearized Freundlich isotherms developed for different oxygen levels. An increase of approximately 300% in adsorption was observed for an increase in the DO level from 2 to 26 mg L-1. Thus, molecular oxygen was found to significantly impact the removals of PCP by peat. The increase in adsorptive capacity of peat was not very significant for an increase in DO level from 2 mg L-1 to 10 mg L-1.However a rapid increase in adsorptive capacity was observed for an increase in DO level from 10 to 26 mg L-1.