Advanced oxidation processes against alkyl phenols in groundwater samples

Spectrophotometric examinations showed the presence of phenolic compounds in the organic residue collected from four groundwater resources located in vicinity of an oil refinery at the outskirt of Tehran. The average concentration of total phenolic compounds was about ۰.۳۸ mg.L-۱ in these samples using Folin-Ciocalteu method. GC-Mass analysis disclosed that alkylphenols were the major phenolic contaminants in the samples. Evaluation of the Advanced Oxidation Processes (AOPs) efficacy for removal of alkylphenols from real water samples is a hot topic of recent Environmental Research due to the decomposition of these compounds in soil and by microorganisms which may results in the formation of structures more resistance against various types of oxidation. To explore the efficacy of AOPs for removal of alkylphenols from the examined groundwater resources, the optimal conditions for three important AOP including Fe۲+/H۲O۲/UV (Photo-Fenton), O۳/UV and O۳/UV/H۲O۲ were first sought using a recalcitrant lab sample containing different aromatic compounds with total concentration of ۲ mg L-۱. Consequently, two methods of O۳/UV (۲ mg L-۱ O۳, ۱۵ min UVC), and O۳/UV/H۲O۲ (۲ mg L-۱ O۳, ۵۰۰۰ mg L-۱ H۲O۲, ۱۵ min UVC) were selected to be examined on the real samples. Although the selected methods were quantitatively effective on the lab sample, they resulted in average removal efficiencies of ۷۹.۷۱% and ۸۴.۱۶% on the real samples, respectively. With respect to the safety regulations, costs and easiness of implementation, the O۳/UV method seems to be more promising for large-scale plans.

کلیدواژه ها:

Alkylphenols ، Underground water ، Ozone ، UV radiation ، Hydrogen peroxide