The Research And Application Of Microelectrolysis-fenton Oxidation In Phenolic Resin Production Wastewater Treatment

Phenolic resins production wastewater has characteristics of high organic concentrations,low pH, strong biotoxicity, etc. Formaldehyde and phenols contained in the wastewater has astrong biological toxicity and it would inhibit most microbials growth. Thus, some measuresof pretreatment should be taken to reduce the water toxicity to meet the follow-up processrequirements. The phenolic resins production wastewater belongs to industrial wastewater thatit is difficult to be disposed. Traditional methods in using physical and biological approachesalone is difficult to meet the treatment standards and serious damages would be caused to theenvironment if it is discharged by improper handling.The commonly treatment approaches at prescent including: Extraction method,Condensation method, Biological method, Fenton oxidation method, Ozone oxidation method,etc. Whereas, the defects of high treatment costs, unsatisfactory effects and complicatedoperation result to some limination to practical application. The paper aims to seek acombined processes tackling with Phenolic resins production wastewater with a stable andhandy operation effects and low costs.Micro-electrolysis approaches combined with Fenton oxidation approaches have manyvirtues such as economical investments, stabling, simple and easy to operate. What’s more,the combined process have a good effect in disposing of the wastewater and comparably easyto achieve industrialization. Last but not the least, the combined processes have anapprarently good effects in improving the biodegradability of water.The phenolic resin production wastewater used in the experiment in this thesis is derivedfrom actual production water from a chemical producing plant. The basis experiment studiedthe micro-electrolysis treatments effects and the Fenton oxidation treatments effects and thecombining effects of them. The experiment concluded the best parameters of each process andthe combinations treatment’s paramenters of them and analyzed the actural operating costs.The project’s design is based on the parameters and the actually process is running well.The main work and conclusions in this paper could be concluded in the following:1) The Micro-electrolysis tested the effects of reaction time, original pH value, aerationvolume and B/C value. The optimum parameters is: reaction time90min, original pH value equals3.0, aeration volume equals2L/min. In this condition, the removal rate of CODcrreached up to about27%; The final pH value stay about5, B/C value increaseed from0.11to0.28.2) The Fenton oxidation tested the effects of dosage of H2O2, dosage of FeSO4, reactiontime, original pH value and B/C value. The optimum parameters is: dosage of H2O210ml/L,dosage of FeSO4equals6g/L, original pH value equals3.0. In this condition, the removal rateof CODcr reaches it maximum of44.3%, B/C value increaseed from0.11to0.21.3)Micro-electrolysis and Fenton oxidation combined process experiment showed that theoptimum reaction parameters is: two stages micro-electrolysis reaction time equals45minseparately, original pH value equals3.0, aeration volume equals2L/min; Altered the outflow’spH value about3.0～3.5and go on with the Fenton oxidation, the Fenton oxidation reactiontime equals90min; Altered the outflow’s pH value about8.0and go on with flocculationexperiment. The experiment on the optimum parameters shows the removal rate of CODcrreached up to57.1%; The removal rate of formaldehyde and phenol reached up to98.3%and85.9%; B/C value reached up to0.35, which is suitable to the following biological process.4) The final treatment processes is determined as “two stages of Micro-electrolysis+Fenton oxidation”，which based on the best parameters of the experiment. The best removalrate of CODcr keeps about35%, the outlet water pH value reaches about7, the removal rateof phenols and formaldehyde reaches more than80%and20%and Per cubic meter of sewagetreatment cost about28.92yuan when the project is actually running.Above all, the Micro-electrolysis and Fenton oxidation combined process treating withphenolic resins production wastewater is available and feasible and have a broadly and widelyapplication value and market prospects.