Pilot Study On The Advanced Treatment Of Corn Processing Wastewater By Membrane Bioreactor And Reverse Osmosis

Corn deep processing industry cost a huge amount of water every year,and recirculating cooling system is also a major part of the water consumption,accounting for about one third of total production water consumption.Carried out the water reuse technology research,the corn deep processing wastewater treatment to the water quality of circulating cooling water water and reuse,it will not only reduce the amount of fresh water,but also can make to reduce total emissions of sewage.So enterprises will obtain economic and environmental benefits at the same time.This study is part of the“12th five-year plan”of national water project“Liaohe typical industry water pollution control and water reuse technology research and demonstration”.This study is also based on the regenerated water reuse project of Siping Tiancheng corn development co.,LTD.A pilot-scale experiment combined process of ultrafiltration and reverseosmosis was used for advanced treatment of mixture which came from the existing aeration tank in the corn procssing enterprise so as to meet the wastewater reuse requirement without the secondary precipitation and pretreatment.The results showed that the average turbidity value of the effluent from the ultrafiltration membrane was 0.1NTU and SS was about zero,which met the requirements of water quality for RO membrance.Conductivily,total hardness and total alkalinity could be effectively removed by RO membrane,RO membrane also had effective separation of COD,NH₃-N,NO₃^--N,PO₄^3--P at the same time.The removal rates of conductivily,COD,NH₃-N,NO₃^--N,NO₃^--N were 96.4%,100%,97.6%,96.9%,99.4%respectively by the whole system.The effluent quality could meet the requirements of Reusing Wastewater Quality Standard for Industrial Circulating Cooling Water?HG/T3923-2007?.The double membrance method for advanced treatment and reuse of corn processing wastewater is feasible in engineering application.MBR choose outer tubular ultrafiltration membrane module,RO membrane module for roll type.By batch experiments,the best operating parameters of ultrafiltration-reverse osmosis were optimized.The results showed that the best UF operating pressure was 0.10MPa,backwash cycle was 30min and backwashing time was 60s;RO optimum operating pressure was 0.7MPa,the recovery rate of RO was10%.Membrane fouling is a common problem in operation of MBR-RO combination craft,and it is also a difficult problem to solve.Membrane fouling membrane will increase cleaning frequency,shorten the life of the membrane,increase operating costs,or even worsen the treatment effect of the system and reduce water quality.Comprehensive analysis,most of the reasons of RO membranes pollution and MBR pollution are same,MBR membrane filtration clipped a relatively large particle contaminants,so RO pollution tends to be more of fine particles.Therefore,under the premise of stable operation of the pilot plant,the performance change of MBR membrane and the RO membrane was focused on,the phenomenon of membrane fouling was analysed,and the pollution factors had been cleared,effective chemical cleaning method had been tried,so as to provide design basis for water special demonstration project and operation experience.