Optimization Of Isolated Soy Protein Wastewater Treatment Process

Since 1980s, China began to develop new soybean deep food industry. In China, the soybean processing industry is currently focused on the development of soy protein. China has built hundreds of soybean producers. There are dozens of large-scale manufacturers. According to China's current level of technology, production of 1 ton of soy protein isolate would discharge 30-35 tons of waste water. However, in our country, because of the unreasonable waste water treatment process selection result out that part of the wastewater discharge difficult to achieve standards.The paper describes the soy protein isolate characteristics of wastewater treatment technologies in the world. For example, a company of 2000 m3/d of soybean protein isolated wastewater treatment projects in Shandong, the article analyzed the defects of the company, found out the key factors that influencing discharging standard, then optimized and improved the technology, achieved good results. The old project used biochemical treatment processes of A/O of "UASB+CASS". The treated water would achieve CODcr>800 mg/L, SS>1300 mg/L, out of the standards. Analyzed the reason, you will find that the wastewater SS is about 5000 mg/L. The concentration is out of the old project's (UASB) ability. As a result, the efficiency of anaerobic treatment phase would be low. The wastewater after anaerobic treatment would change, CODcr> 2000 mg/L, SS> 4000 mg/L. This kind of wastewater flowing into aerobic phase would result that the treated water couldn't achieve standards.The transformation is based on SS removal from wastewater r as a breakthrough. Enhanced biological treatment facilities, improved in efficiency, in order to achieve the purpose of discharge standards. The subject adopts "physicochemical and biochemical" processing routes to optimize the original process. To ensure the anaerobic phase of the treatment effect, it is necessary to remove SS in front of the flotation of anaerobic. It dose not only reduce the overall load of biological treatment systems, but also to ensure the stable operation of anaerobic processes. It is the basis of the overall project compliance and stability. Use EGSB anaerobic treatment processes instead of UASB, the processing efficiency improved from less than 80% to 90%. The result indicated that use EGSB process to discharge soy protein isolate wastewater is feasible. The project rebuilt "two A/O" process based on 2 original CASS pool after anaerobic. The process of NH3-N treatment effect was better than CASS process. The stability of the overall project has played a key standard role. Block 1 new secondary sedimentation tank, the remaining organic pollutants and ammonia nitrogen to be removed. There was a good wastewater treatment efficiency of soy protein isolate through to transform the structures. After the transformation in the project, the effluent CODcr<100 mg/L, NH3-N<15 mg/L, SS<70 mg/L, achieved "Integrated Wastewater Discharge Standard"(GB8978-1996) Table 4 emission standards in the level and achieved the emissions standards.