Experiments On Phenol Oxidated By Cavitating Water Jets With H₂O₂

Phenolic contamination is a sort of representative organic pollutants which are difficult to be degraded. The numerous amount of phenolic contamination is doing great harm to the environment and can be widely found in industrial waste water. So it must be discharged with an adequate treatment. The disposal methods of phenolic waste water include physical chemistry technology, biology and advanced oxidation technology, etc. However, these methods all have some shortcomings, for instance, treatment is not thorough. High presssure and high temperature could be produced after the crumble of cavitation bubble, which could impel the H2O2 in the solution to decompose into·OH and degradation of organic contamination. Some scholars have applied it to the purification of some wastewater such as PCP, benzene and toluene, but further research needs to be carried out on phenolic waste water with cavitation technology.This paper adopts three ways to deal with phenolic waste water and explores each kind of effecting effect on removal of phenol, these three ways are the technology of H2O2 oxidative degradation, the technology of cavitating water jets and the technology of H2O2 oxidative degradation combined with cavitating water jets. The intermediates and by-products of the technology of H2O2 oxidative degradation combined with cavitating water jets on phenol were analyzed with HPLC and the mechanism of reaction also has been confirmed. Meanwhile the dynamical model of the technology of H2O2 oxidative degradation combined with cavitating water jets has been deduced. The main contents are as follows:①Through the laboratorial study on the technology of H2O2 oxidative degradation of phenolic water, the optimal reaction condition was concluded: investigated pH 3.0, reaction time 180min, initial phenol concentration 50 mg /L , phenol volume 1L, initial concentration of H2O2 300 mg /L , under this optimal reaction condition, most 31.7% of phenol can be removed.②The technology of cavitating water jets was adopted to deal with phenol. Its volume and concentration were 64Land 100 mg /L , the removal of phenol was about 17% after 3 hours'reaction. Through the laboratorial study on the technology of H2O2 oxidative degradation combined with cavitating water jets on phenol, the optimal cavitation condition was obtained: investigated pH 3.0, initial concentration of H2O2 300 mg /L , initial phenol concentration 100 mg /L , confining pressure 0.5MPa, cavitation time 12times, pumping pressure 20Mpa, under this optimal cavitation condition, most 99.85% of phenol can be removed.③Through examing the influence of dosage of·OH radical scavenger to degradation effect of phenol, the mechanism of cavitating degradation of phenol is oxidizing of·OH. And the mechanism of reaction of the technology of H2O2 oxidative degradation combined with cavitating water jets on phenol also has been confirmed by HPLC. The first step, catechol, hydroquinone and p-benzoquinone were produed which confirmed the existence of·OH. The second step, maleic acid and acetic acid were produed which was the result of phenyl's oxidation .④Synergetic effect of cavitation and H2O2 has appeared in the technology of H2O2 oxidative degradation combined with cavitating water jets on phenol. The promoted factor for phenol degradation rate constant is found to be at about 38.419. A simplified mechanistic model for phenol degradation was deduced.The innovation of this paper lies in applying cavitating water jets to phenol waste water. The mechanism of cavitating degradation of phenol also has been revealed. And the dynamical model of the technology of H2O2 oxidative degradation combined with cavitating water jets has been deduced. This study can give important theorical and practical direction to the disposal of organic substance such as coke plant wastewater.