Effect of ultra sound on ۳-chlorop henol de gradation, compari son with Fenton's reagent effect

The study of chemic al effects of ultrasound on organic systems is of interest b ecause of t he widespread universal tries for w ater purifying[۱]. It's chemical eff ects reveale d because of generate d cavities du ring acoust ic wave transmitting the solution w hich collaps ed and lead to chemical damage that called sonolysis[۲-۴]. In brief sonolysis is due to high local instantaneous temperature and pressure that made in solution after cavitation[۵]. It has be en proposed that ultra sound-induced reactions in aqu ous soluti ons involve free-radical mechani sms due to the formatio n of hydroxy l radicals[۶ ].The kinetic study of ultrasonic and Fenton's reagent as sisted degra dation of ۳-chlorophenol in water was perfor med to compare them. Fenton's reagent consist of FeSO۴ and H۲O۲ that produces .OH in water medium[ ۷]. Apparent kinetic rate constants w ere studied. Comparati ve analysis revealed that ultrasound irradiation using comp ared with catalytic case increased rate constant from ۰.۰۰۱۶ min-۱ to ۰.۰۰۵۱ min-۱ that showed about ۳-times higher degradatio n rate. In combination method the rate constant reached to ۰.۰۰۷۲ min-۱ that is more than one of others. T he more . OH radicals produced in combination metho d caused th e larger rate constant was observed. The observed degradation seem to be related .OH radical attacks to phenol ring that ring made be transient and break it[۸].

کلیدواژه ها:

۳-chlor ophenol ، Ultrasound ، catalyst ، Fenton's reagent ، degradation.