(cest2017_00519) Effects of radiolytically produced reactive species on 2- methylisoborneol and geosmin in water

摘要

Water radiolysis is known as an Advanced OxidationProcess (AOP) for treatment of organic pollutants but itcan also serve as a useful tool to study the effects of highlyreactive species that are commonly present in AOPs. Suchstudies are carried out in simpler homogeneous systemsthat can be manipulated with use of scavengers toselectively produce different oxidative (OH·, OOH·, O2-,H·) or reductive species (eaq-, H·), at known yields that areproportional to irradiation dose. The aim of this study wasto investigate the effects of the above reactive species ontwo commonly occurring, cyanobacterial taste and odourcompounds, 2-methylisoborneol (MIB) and geosmin(GSM), upon steady-state radiolysis using 60Co gammarays. Degradation processes and products were monitoredusing headspace (HS) solid phase micro extraction(SPME), followed by GC-MS. Results showed thatdegradation of both MIB and GSM was faster whenhydroxyl radical (OH·) is the reactive species and slowerwith hydroperoxyl radicals/superoxide (OOH·/O2-) orhydrated electrons (eaq-). Degradation products indicateddifferent reaction pathways that depend on reactivespecies, i.e. oxidative (OH·) versus reductive (eaq-), as wellas on chemical structure of the initial compound. Thoseresults can be valuable in understanding and evaluating therole of reactive species in AOPs for water treatment.