The Experimental Study On Yeast Wastewater Treatment Process

The yeast wastewater has the characteristics of high COD concentration,high chroma,high sulfate concentration and difficult biodegradation.The pollution of yeast wastewater to the environment is becoming a serious problem and the bottleneck of the development of domestic yeast enterprises.This paper aims at the problem of low removal efficiency of existing yeast wastewater treatment processes,the wastewater treatment process of yeast at present was analyzed,appropriate treatment options were explored.at last,pretreatment-two stages EGSB-desulfurization-aerobic process-advanced treatment process was used to treat yeast wastewater.the optimal process parameters were got.(1)Pretreatments: the yeast wastewater was pretreated by iron-carbon microelectrolysis.The optimal operating conditions determined by orthogonal experiments were as follows: pH value of 4,Fe /C of 2:1,iron dosage of 40 g /L,reaction time of 3h.The yeast wastewater was treated by iron-carbon micro-electrolysis,the effluent COD concentration can reach about 3000mg/L,and the average removal rate of COD was above 40%.(2)The first EGSB: the temperature maintained at room temperature,pH at 6.5~7.0,HRT: 48 h,reflux ratio of 100%;The second EGSB: the temperature maintained at room temperature,pH at 6.8~7.2,HRT: 24 h,reflux ratio of 100%.(3)Advanced treatment: The advanced treatment of aerobic wastewater was flocculation and precipitation method with poly aluminum chloride(PAC).The optimal operating conditions determined by orthogonal experiments were as follows: pH value of 8,PAC dosage of 40 g /L.After the advanced treatment,the COD and chroma of effluent were 82.19mg/L and 20 times respectively,which reached the discharge standard of yeast wastewater.The experimental results show that the combined process has high treatment efficiency in the treatment of yeast wastewater,and has a certain reference value in the future application.