Application Of Triple Evaporators And Membrane Bioreactor For CMC Waste Water Treatment

Carboxymethyl Cellulose(CMC),namely industry gourmet,is a qualified additive that approved by FAO and WHO,and widely used in food,toothpaste,ceramic,drilling,battery,etc because of its good characteristics.The wastewater generated from CMC process contains high salt and high COD.It is one of the most difficult industrial wastewater to be treated.The higher efficiency and lower cost treatment of this waste water has the practical significance.In this study,an analysis for the existed simple evaporator in a Guangdong CMC plant was conducted at first,the results indicated that its discharged COD was about 90mg/L,which was higher than the request of < 60mg/L according to GB31571-2015.Furthermore,the wastewater treatment cost per ton CMC was > 550 Yuan.Based on the study of similar domestic and international processes,the treatment efficiency,total investment,land using,operation cost etc were selected as the optimization target for the design of new wastewater treatment process.Aspen was used to simulate the multi evaporators to optimize the operational condition for reducing the energy consumption in the process and improving the equipment reliability.Finally,the triple evaporators and membrane bioreactor was chosen as the wastewater treatment process,the details of the triple evaporators and membrane bioreactor were given with optimal design for improving the treatment efficiency.The industrial application results of the optimal design showed that,under condition of the 50,000~80,000mg/L of inlet COD level and 30% of the salt content,the final discharge of the new waste water treatment process was less than 60mg/L,which meets the request of GB31571-2015.At the same time,the operation cost is reduced to under 50% of original level.