Study On Intercirculation Anaerobic Reactor And Trentment Of Paper Mill Comprehensive Effluent

In this paper, the structure and working principles of the IC reactor are presented. The fundamental mechanisms, which include the hydrodynamic model, are discussed in details. Aiming at guiding the reactor design as well as operation, the application of these mathematical models in practice is explored. Meanwhile, software was developed to simulate this process by using the Visual C++ language. The article also provides some ideas and principles in reactor and process flow design.The model of influent and the best diameter of circulation pipe in IC ractor is established with grey system method.With the strengthening of people's consciousness on environmental protection and the proposal of sustainable development strategy, the treatment of paper-mill effluent has become the crucial problem for the survival and development of our papermaking industry. As the economical and effective method in treating high strength organic effluent, the Anaerobic treatment shows it's great attraction to remove the pollution caused by paper-mill effluent. At the same time, there are more and more successful experiences of treating paper-milleffluent by high effective anaerobic reactor in many developed countries, which make the treatment possible in our country.In this paper, a lab-scale internal circulation was designed aiming at treating comprehensive effluent from alkaline straw chemical pulp. The performance of the IC reactor was studied in treating the glucose effluent, on the basis of the study on the IC reactor's performance, the quick start-up of the lab-scale IC reactor in treating the comprehensive effluent from the straw pulp was studied.The study on anaerobic biodegradation of the effluent from alkaline straw chemical pulp indicates that the BOD5/ CODcr of the black liquor increased from 0.27 to 0.32, the COD removal increased about 14% after the lignin was deposed using acidThe BOD5/ CODcr of the comprehensive effluent reached 0.3, COD can be removed about 51.4%, and the BD% was 60.66. For these data we can conclude it will be feasible treating the comprehensive effluent from alkaline straw chemical pulp by anaerobic treatment.The study on the performance of the IC reactor shows that the start-up of IC reactor at the volumetric loading rate of 6kgCOD/m3.d could be finished in 20 days, internal circulation was well performed, the volumetric loading rate reached 11 kgCOD/m3.d ,and the COD removal was above 80%.During the course of stable running, IC reactor system can show it's better effect with hydraulic retention time 5.3h and the volumetric loading rate of 32kgCOD/m3.d. The characteristics of granular sludge changed greatly after the running: granular diameter increased, the highest sedimentation rate was enhanced to 98.4m/h, VSS/TSS was increased from 80% to 91.7%.The result of the study on the quick start-up of the lab-scale IC reactor to treat the comprehensive effluent from the straw pulp shows that the start-up can be finished in 38 days, with the volumetric loading rate of 18 kgCOD/m3.d and the hydraulic retention time of 8h, 62.8% COD and 78% BOD5 could be removed, and 0.291/1.d biogas produced rate was reached.