The Study Of Lower Concentration Oily Wastewater Treatment With A New Designed Oil-water Separator

In today’s society, oily wastewater pollution has been rather serious. Theemission of oily wastewater has unpredictable impacts on the ecological equilibrium,environmental maintenance and other aspects. Also, recycle of oily wastewater isimperative. Therefore, the treatment of oily waste water has considerable ecologicaland economic value.Nowadays coalescing oil-water separation is widely used, which shows lots ofadvantages, like its unnecessary of extra chemical reagents, avoidance of secondarycontamination and low operating costs. Much research has been performed on thecoalescence material and separator form.This project focuses on the designing of the new oil-water separator, thusrealizing the integration of coalescing tank and separation tank and the synchronizationof coalescence and separation, solving the problem of the overlarge coverage of theexisting oil-water separator. The application of the device on the treatment of oilywater in the laboratory has been performed. The oily sewage reuse and oil recoverycome true. Meanwhile, emphasized research is performed on the recycle andregeneration of fiber layer. The longtime running of the device has been preliminarilyrealized.The optimization study indicates that the novel oil-water separator showsoptimum processing performance when the body is cylindrical with a diameter of20cm while using single stage fiber layer made of lipophilic fiber A. The optimizedoperating conditions are as follows: fiber layer thickness7cm, water flow <1.8L/min,fiber fill rate125kg/m3, under which conditions the effluent oil concentration canreach less than0.3mg/L.Single factor standard addition experiments show that when filled with thelipophilic fibers A, the device can tolerate a maximum LAS concentration of15mg/L,a pH range of3~9. The addition of electrolyte substances can effectively improve thetreatment effect. This device can be applied to the treatment of various kinds of oilywastewater. According to the research on the treatment of engine oil and lubricating oilwith water, it is concluded that the treatment always shows a better effect when the oilcontained in the wastewater displays a greater kinetic viscosity.By the long-time operation study, a new theory: the is put forward which is thenew fiber layer covered with oil slick. The stability time of the original period inoperation greatly are shortened from5~7d to3~5h, thus the operating efficiencyincreased accordingly. Through a long-term exploration and attempt, the operation mode the front-end jet and back-end recoil are proposed to solve the oil-pluggingproblem. A series of parameters are obtained as follows. When the water flow ismaintained at about0.8L/min, the outlet water becomes standard until the front endwater pressure reaches0.8mH2O. When it runs into2.0mH2O and recoil once every12hours. When the pressure rises to3.0~3.5mH2O, front-end jet and back-end recoil,and then repeat the operation recoil once every12h. The operation cycle of the fibersprolongs from60h to150h successfully. By changing the filling way of the fiber layer,the pressure rise of fiber layer is effectively decelerated.