Research On Treatment Of Oil Emulsion Wastewater In Mechanical Processing Industry

For the past few years, the emission load of emulsion oily wastewater is more and more, harm of which to environment is increasingly highlighted and seriously affect the ecological balance and the natural life of humans. So, the treatment problems in the emulsion oily wastewater have been received more and more attention.The traditional treatment of oily wastewater is first put the wastewater coagulation demulsification and after that do biochemical treatment, resulting in the large consumption of chemicals in the process of coagulation. The emulsion oily wastewater show a good biodegradability in early trials, based on which, we plan to use “active sludge biochemical treatment + coagulation” treatment process to deal with it. This way can utilize the activated sludge wastewater to degrade organic composition in the first, to a certain degree, it can reduce the consumption of chemicals in the process of coagulation. Finally, the experiment gets the desired effect, the main conclusions are as follows:(1)Using emulsion diluted with sewage to domesticate the activated sludge gets a better treatment effect. On the one hand, the volume of sewage is in the majority, in the mixed wastewater, which can provide a large amount of nutrient elements for activated sludge; on the other hand,the concentration of the oil substances in the mixed wastewater is not very big, which could not inhibit the activity of the activated sludge.(2)When using the method of activated sludge to do the biochemical treatment to the emulsion wastewater, found that under the condition of room temperature 20℃, pH = 6.0~ 8.0, the initial reactor COD is at most 6.0×103 mg/L, near 30 hours of aeration time, the activated sludge can degrade COD of emulsion wastewater to below 1.0×103 mg/L, the removal rate can reach more than 80%, the water seems milky white opacity,but it did not get a obvious effect on the degradation to the oil substance of waste water.(3)On the demulsification of emulsion wastewater, by using acidification, salting out, and the coagulation process respectively to treat the wastewater, it is considered that the effect of using polyaluminium chloride with polyacrylamide is better. Under the condition of pH = 8.0 ~ 9.0, dosing quantity of PAC is 1.4×103 mg/L, dosing quantity of PAM is 50 mg/L, the COD removal rate can reach to 70%, oil substances removal rate can reach to 90%, gets a good effect.