The Studies On The Treatment Of Paes By The Way Of Al-C Micro-electrolysis And Biological Contact Oxidation

Phthalic acid esters (PAEs) are widely used in industrial production as plasticizers.PAEs is anew persistent pollutants commonly found in air, water, soil and biosphere. Some recently studiesreported the volatilization and hydrolysis of PAEs were very difficult, it can easily accumulate inthe sediments or adsorbed on the surface of soil particles. With the increasing of PAEs in theenvironment, the research of removal technology of PAEs has become increasingly important.The experimental research on the treatment of PAEs by the way of Al-C micro-electrolysisand biological contact oxidation and analysised by high performance liquid chromatography(HPLC). Main research contents:(1) The optimum reaction conditions were determined byorthogonal test and single factor test;(2) Enhance the effect of Al-C micro-electrolysis bychanging the other condition;(3) The different between removal of COD and PAEs by differentfiller and different biofilm mode were studied in the boot process biological contact oxidationpond.(4) The factors which influence the treatment effect were also studied during the operation.The experimental results are summarized as follows:(1) According to the orthogonal test, the initial conditions of Al-C micro-electrolysis weredetermined as following: The pH value of12, Al/C rate of1:1, reaction time of60min. At thesme time, the order of single factor test was determined as pH, Al/C rate and reaction time.(2) The optimum parameters of Al-C micro-electrolysis were determined as following: ThepH value of12, Al/C rate of1:1, reaction time of30min. Under these conditions, we can achievethe optimum reaction effect, the removal rate of DMP was49.94%.(3) By changing the treatment of other conditions can alter the effect of Al-Cmicro-electrolysis. Ultrasonic could enhance the processing effects while the DMP、DEP andDBP degrading rate could reach63.38%、32.75%、32.23%respectively. Adding a little bit ironand copper could also enhance the processing effects, but it would achieve the opposite resultwhen add H2O2to the system.(4) Compared with K1filler, reed have a quick biofilm speed, more oxygen and lessmicroorganism in unit volume. After completion of biofilm, the COD removal rate was75.9%byreed filler, and90.48%by K1filler.(5) According the different biofilm ways in the boot process by K1filler, inoculation biofilmhave a quick biofilm speed. The K1filler surface adhere biofilm in about a week, but the naturalbiofilm need two week. The inoculation biofilm method can removal COD in the beginning, butnatural biofilm method can not removal COD in water. Unexpectedly, they almost have the sameCOD removal rate.(6) The removal rate of PAEs increased gradually with the running time by the result ofdomestication of microorganism. At the beginning, the DMP、DEP and DBP degrading rate were57.8%、52.6%、45.7%，and the degrading rate arrived the maximum value at the end of the domestication process when the DMP、DEP and DBP degrading rate were96.1%、93.7%、97.1%respectively.(7) The effect of the removal of PAEs was observed by changing the hydraulic retentiontime, influent pH and aeration intensity. It was found that longer HRT correspond higher PAEsremoval rate. What’s more, influent pH also have influence on the removal of PAEs. Too acid ortoo alkaline will inhibit the microorganism’s activity. In addition, low aeration cause lowdissolved oxygen, then decrease the treatment effect. On the other hand, excessive aerationdoesn’t have advantages to biofilm attachment and it’s also increasing the power consumption.