Research On IC Reactor+A/O+Physicochemical Treatment Process In The Treatment Of Soybean Protein Wastewater

With rapid development of soybean protein processing industry, pollution caused by soybean protein wastewater is getting more and more attention. As a kind of concentrated organic wastewater, soybean protein wastewater is quite difficult to be disposed of due to its complicated composition and large amount of organic matters.On the basis of consulting a large number of domestic and foreign literatures, Internal Circulation(IC)-Anacrobic/Oxic(A/O)- Physicochemical treatment process was adopted to treat soybean protein wastewater.IC and A/O experiment was performed in pilot-scale while physicochemical treatment in lab-scale.Firstly, optimal operating parameters for granular sludge acclimation and start-up of IC anaerobic treatment was selected to guarantee the stability and efficiency of the reactor. After that, optimal selection parameters for denitrification and phosphorus removal of A/O treatment was also chose to ensure efficiency and achieve energy-saving and cost-reducing.Finally, economic and efficient advanced treatment was selected to achieve wastewater discharge standard, by using coagulation and absorption method. The main conclusions were summarized as follows:1. IC anaerobic reactor was started successfully.The organic load was 9.5 kgCODCr/(m3·d) and CODCr of effluent was below 1000 mg/L, while the removal rate reached 80%. The load of the follow-up biological treatment unit was reduced after IC reactor.2. During the start-up of the IC reactor, The water quality indexes, such as pH、temperature、volatile fatty acid (VFA), should be tested regularly to ensure the system worked well and take corresponding measures in the case of organic loading shock.3. Mature granular sludge was produced by inoculating the reactor with floe sludge from municipal sewage treatment plant.The granular sludge was black and ellipsoid with clear boundary.Particle size of it was about 0.5 to 3 mm.The cost was reduced greatly, compared to the direct inoculation of granular sludge.4. The CODCr removal rate of A/O treatment is more than 80% and the denitrification and phosphorus removal effect is also quite good. The effluent concentration of CODcr 70-90mg/L while the one of NH3-N is less than 5mg/L.5. CODCr was futher removed by using the coagulation and absorption physic ochemical advanced treatment. As a result,the indicators of effluent was lower than the limits of the discharge standards of Shandong Province (CODcr< 60mg/L,NH3-N<5mg/L).The concentrations of coagulant (PAC)、coagulant aids (PAM) and adsorbent (Activated Carbon) are 4mg/L,0.5mg/L and 30mg/L...