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DESTRUCTION OF PCBS USING SULFATE RADICAL-BASED ADVANCED OXIDATION PROCESSES
Citation:
RASTOGI, A., S. R. AL-ABED, AND D. D. DIONYSIOU. DESTRUCTION OF PCBS USING SULFATE RADICAL-BASED ADVANCED OXIDATION PROCESSES. Presented at American Society National Meeting, Chicago, IL, March 25 - 29, 2007.
Impact/Purpose:
to present information
Description:
Polychlorinated biphenyls (PCBs) are a class of 209 congeners that were extensively used in industrial applications during 1929 to early 1970s, The presence of PCBs in the environment poses long-term risk to public health and wildlife due to their persistent and toxic nature. Advanced oxidation technologies (AOTs) are suitable for removing these non-biodegradable and toxic organic compounds from water and wastewater. In AOTs, the reactions follow a specific oxidation pathway, which, in most of the cases, includes the formation of extremely reactive hydroxyl radicals which readily oxidize most of the organic contaminants. Recently, AOTs based on sulfate radicals (SR-AOTs) have attracted a lot of attention because of certain advantages over conventional AOTs and fewer application limitations for the destruction of organic pollutants in wastewater. Peroxymonosulfate (PMS) (available as Oxone a Dupont product) and persulfate (PS) are two common oxidants used for sulfate radical-based oxidation processes. PMS is used as a powerful oxidant for a wide variety of industrial and consumer applications. It is an active ingredient of the triple salt (2KHSOs'KHSO4'K2SO4), commercially manufactured as Oxone by Dupont. Due to its harmless nature and affordability, Oxone is frequently used in graft copolymerization, specific cleavage of DNA and initiation of chemiluminescent reactions. It is also used as bleaching agent in swimming pools and paper and pulp industry. When used as the oxidant, PMS often oxidizes faster than hydrogen peroxide (Eo HSOS-/HS04- = + 1.82V; EO H202/H20 = + 1.76V) and is more stable than hydrogen peroxide. Anipsitakis and Dionysiou studied the cobalt (Co) based activation of PMS for the degradation of chlorophellols. Co-PMS system was found to be superior to Fenton reagent and showed no pH limitation for degradation of 2, 4;-DCP and atrazine. However, the use of cobalt may adversely affect the quality of environmental systems. This study investigates the degradation of recalcitrant polychlorinated biphenyl (PCB) using a new class of sulfate radical-based advanced oxidation processes (AOPs). These AOPs are based on the generation of sulfate radicals through Iron (Fe (II), Fe (III)) mediated activation of PMS. In this study, iron (Fe (II), Fe (III)) was selected as the transition metal because of its environmental friendly nature and cost effectiveness.