The Study Of Demulsification-Fenton Treating Method For Emulsifying Wastewater With Oil

Emulsifying wastewater with oil is derived from many industries such as petrochemical industry, dyeing and printing industry, machine machining, food producing and so on. It has a few characteristics such as wide varieties, large capacity of drainage, complicated component and high chemical oxygen demand (COD).It is a class of unmanageable organic wastewater and harmful to eco-environment if it is discharged to environment directly. Therefore, the kinds of emulsifying wastewate rmust be treated effectively. However,it is difficult for the traditional single physical or chemical or biological methods to reach efficiency degradation. To resolve this problem, the joint approach was used to make up deficiencies in individual technology and achieve the discharge standards of oily wastewater.A chemical emulsion breaking-Fenton reagent method was used in this article. The relationships between the effect of the main factors to the emulsion breaking reaction and Fenton reaction are investigated.The parameters are optimized. The best treatment conditions are ascertained. According to the experimental study on the treatment of emulsifying wastewater with oil, the main contents and results are as follows:(1) From the demulsification experiment, CaCl2 is better than MgSO4 and MgCl2. And a mixture of CaCl2 and AICl3 polymer is better than CaCl2 singlely. The best experimental conditions of emulsion breaking are as following:adding CaCl 1.5g /L; stirring speed 70r/min; stirring time 10min; temperature 40℃; pH 5; then adding AlCl3 polymer 1.5g/L; stirring speed 70r/min; mixing time 20min; optimal settlement time 15min. Under this condition,the COD removal was over 85%. (2) The parameters'effectiveness of the Fenton reagent oxidation was determined by orthogonal experiments:[Fe2+]/[H2O2] ratio (mole ratio)> FeSO4 adding dose > the initial pH conditions> reaction time.The optimal condition is obtained by the orthogonal experiment method and is showed as following:Fe2+ adding dose 1.7g/L; H2O2 adding dose 6.5ml/100ml;pH 2.85; reaction time 2h.Then the COD removal is more than 85% and better biodegradability is achieved for BOD5/COD 0.45.(3) The researeh shows that chemieal demulsification-Fenton reagent oxidation-SBR biochemical-activated carbon adsorption process have a good effect in emulsifying wastewater with oil,which can be applicated by a engine manufacturing corporation in Xi'an. The effluent can meet "Integrated Wastewater Discharge Standard" (GB8978-1996) and the second category of pollutants discharge standard of "the Weihe River (Shaanxi above) Integrated Wastewater Discharge Standard "(DB61-224-1996).