| Pharmaceutical wastewater with high concentration of organic matter, difficultbiodegradation, high toxicity, big impact load, is difficult to meet current discharge standards bythe conventional biochemical treatment technology. Especially, a few of mother liquordischarges into the original water treatment system irregularly, has a strong impact on biochemicalsewage treatment system, so that the water quality index of effluent exceed the standardfrequently.At present,the main pretreatment of the pharmaceutical wastewater include the coagulation,chemical flocculation, gas float, adsorption, micro electrolysis, electrolytic, Fenton and ozoneoxidation. These methods are not used widely because of its complex operation and high cost.In view of this situation, this paper aims to seek a pharmaceutical mother liquor wastewaterpretreatment process with simple operation and low cost.With the study of cavitation, it was found that cavitation technology could provide a newwater treatment technology and method in toxic organic wastewater treatment. Hydrodynamiccavitation had the advantages of low cost, simple device and easy to realize industrializedapplication in wastewater treatment. In order to further study on the hydraulic cavitationtechnology research and application in water treatment, more attention are paid to thecombination hydraulic cavitation with oxidation reagent, strengthen the amount of freeradicals’s production to achieve a higher removal rate of organic pollutants. The mainadditives included H2O2, Fenton reagent, ozone, Fe2+, etc.On the basis of the study of domestic and foreign literature, a set of hydrodynamiccavitation coupling ozone oxidation processing equipment is designed. The equipment is usedto study the effect on CODCrremoval rate with different factors in pharmaceutical wastewatertreatment, the factors including ozone dosing, inlet pressure and reacting time. The result isprovided for the optimum operation parameters, the process is applied to practicalengineering.Major work and conclusions of this paper could be divided into the following sections:1) Different operating parameters such as ozone dosing, inlet pressure and time areanalyzed especially on the effect of the pharmaceutical wastewater CODCrremoval rate. The results proved that operating parameters such as ozone dosing, inlet pressure and time had aneffect on the pharmaceutical wastewater CODCrremoval rate, CODCrremoval rate could reachto21.15%with the optimal operation parameters, inlet pressure0.41Mpa and ozone dosage1.812g/h, treatment time60min in the pharmaceutical wastewater treatment by the way ofhydrodynamic cavitation coupling ozone oxidation processing.2) Ozone oxidation and hydrodynamic cavitation is used in pharmaceutical wastewatertreatment respectively. The CODCrremoval rate by hydrodynamic cavitation coupling ozoneoxidation processing is2.52times of by ozone oxidization treatment,17.33times of byhydrodynamic cavitation treatment and2.2times of ozone oxidization and hydrodynamiccavitation together. The results show the synergistic effect between hydraulic cavitation andozone.3) Flocculation Experiment.The optimum dosage is confirmed by the comparison ofprecipitation effect, which PAM dosage is4.5mg/L and PAC dosage is45mg/L.4) The flocculation deposition effluent is reprocessing by hydrodynamic cavitationcoupling ozone oxidation treatment experiment. The CODCrremoval rate of pharmaceuticalwastewater is reached to49.95%after the30minutes processing.5) The main pharmaceutical wastewater treatment process of “hydrodynamic cavitationcoupling ozone oxidation+flotation+hydrodynamic cavitation coupling ozone oxidation” isdetermined. It can be effectively used in the pharmaceutical wastewater treatment.Thistreatment process have been applied in a pharmaceutical factory and treatment effect is goodwith CODCrremoval rate over40%on average.Above all, it is feasible for pharmaceutical wastewater treatment by using hydrodynamiccavitation coupling ozone oxidation, it have a very good application prospect in organicwastewater treatment engineering. |
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