| This paper takes the PVC production waste water of Shaanxi Xi'an Chemical Factory as the object of study.In that the PVC production waste water has distinctive features such as high concentration of organic matter,high turbidity,and poor biodegradability.Therefore,the thesis makes scientific research on treating the PVC production waste water with the coagulation-sedimentation-Fenton oxidation technology.Fenton reagent advanced oxidation technique has covered several fields of industrial waste water disposal,which has bright application prospects.However,up to the present,there is no report on Fenton advanced oxidation technique of treating the PVC production waste water.So the thesis on the coagulation-sedimentation-Fenton oxidation technology treating the PVC production waste water,not only has broadened the application field and has laid the necessary foundation of Fenton oxidation technique,but also has practically provided a new technical method for treating the PVC production waste water.The thesis,through PVC production waste water treatment experiments,comes to a conclusion about the best technical parameters of the coagulation-sedimentation-Fenton oxidation technology treating the PVC production waste water of Shaanxi Xi'an Chemical Factory.The conclusion has theoretical significance and practical significance for the practical project of PVC production waste water treatment.The thesis,through coagulation experiments on factors such as coagulant type, dosage and pH value,comes to a conclusion of the optimum reaction condition in coagulation stage.The thesis,through Fenton oxidation experiments on factors such as pH value,hydrogen peroxide dosage,ferrous sulfate dosage,reaction time and temperature,comes to a conclusion of the optimum reaction condition in Fenton oxidation stage.In terms of the optimum reaction condition in coagulation stage and in Fenton oxidation stage,through coagulation-Fenton oxidation of the joint experiments, the thesis comes to following conclusions.(1) The best operating parameters and processes of coagulation-Fenton oxidation technology are as follows.At atmospheric temperatur,400ml PVC production waste water is poured into a 500ml beaker.After pH value adjusted to 9,the beaker is placed on the mixer.Adding 60.0mg/L of PAC into the beaker.At the same time,the mixing is beginning.In the rapid mixing,velocity gradient G value is 247.81/s and mixing number GT value is 29,737.34.In the slow mixing,velocity gradient G value is 106.40/s,and mixing number GT value is 95,758.36.The rapid mixing takes 2min and the slow mixing taks 15min.Then static settlement stands for 60min.The supernatant, obtained from that beaker to a clean 500ml beaker,is adjusted its pH value to 2.Then the beaker is placed on the mixer.Adding 0.9g/L ferrous sulfate and 0.27g/L hydrogen peroxide,PVC production waste water is started mixing at the same time.In the mixing, the velocity gradient G value is 247.81/s and mixing number GT value is 297,373.41. The mixing takes 20min.Then static settlement stands for 60min.After above treatments,PVC production treated waste wate is adjusted pH value to 6 to 9 and is filtrated with filter paper and glass funnel.Analysis the COD and turbidity of PVC production percolated waste water.The PVC production treated waste water can be discharged.(2)The coagulation-Fenton oxidation process of PVC production waste water treatment effect:PVC production raw waste water COD is 1041.37mg/L;Turbidity is 426NTU;Suspended solids is 1158.37mg/L.After coagulation-Fenton oxidation treatmen,PVC production treated waste water COD is 56.66mg/L in average;Turbidity is 2.01NTU in average;Suspended solids is 14.19mg/L in average.The average COD removal rate is 94.56 percent;The average turbidity removal rate is 99.53 percent;The average suspended solids removal rate is 99.22 percent.It shows that by coagulation-Fenton oxidation process treatment,PVC production treated waste water quality index both meet our national standards level 1 for wastewater discharge.In a word,the coagulation-Fenton oxidation process treating the PVC production waste water of Shaanxi Xi'an Chemical Factory is feasible.By the coagulation-Fenton oxidation process treatment,PVC production treated waste water quality objectives can be achieved our national standards level 1 for wastewater discharge.
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