Study On Treatment Of Wastewater From Purification Of Restaurant Oil-Smoke

In this paper, the purpose of the study is to find a treatment method for the wastewater from purifying restaurant oil-smoke by wet purifying device.The method should be simple, easy to be controlled , economical ,and efficient .The effluent must reach discharge standard so that the secondary pollution of the wet purifying devices can be eliminated and the capacity of the equipments'market competitiion can be further strengthened.According to the properties of this wastewater from purifying oil-smoke of restaurant, the regulations of corresponding discharge standard, a lot of references and selective comparisons of treatment methods, Coagulation technique is adopted to treat the wastewater from purifying oil-smoke of restaurant. Coagulation process is simple, easy to be controlled , economical and efficient.It is of many advantages, such as breaking emulsification,removing oil and reducing the surfactants'disturbtance to the follow-up treatment and so on. Therefore, Coagulation technique is suitable to treating wastewater from purifying restaurant oil-smoke of restaurant which has much detergents and been emulsified largely. After the comparision of flocculation efficiencies of FeCl₃,PAC,AlCl₃,Al₂(SO₄)₃ and Fe₂(SO₄)₃,FeCl₃ is adopted .The results show that the flocculation efficiencies of FeCl₃ is favorable and the treated effluent can reach the regulations of discharge standard by FeCl3 flocculant.The removal efficiency of CODCr is above 70% in the following conditions: 250 mgFeCl3/L dosage , 15min sedimentation time , 120 r/min mixed rate, and 1 min mixed time. And the effluent treated could meet the regulations of Discharge Standard for municipal wastewater (CJ3082-1999) and the Rank 3 of Integrated wastewater discharge standard(GB8978-1996).The research result has been used in the practice. the effluent treated by the method above has been used as washing water in the purification of oil-smoke so that the fresh water is saved.The method enhances the competitiveness of wet fume purification equipment in the market.