Study On Two-grade Biochemical Treatment Of Biogas Slurry And Organic Matter Degradation

The biogas slurry can be treated by returning and natural biological systems,while a lot of land is needed and biogas slurry returning is also restricted by season changes.Other treatment patterns,such as fermentation bed treatment,are restricted by many factors.The pattern of industrialization is an alternative choice for biogas slurry treatment for the region with limited land resources.The deep treatment of the large amounts of biogas slurry is inant difficult,which have been widely conducted by many estic scholars.Recently,the deep treatment of biogas slurry exhausted large expense on treatment technology and operation.Moreover,the environmental protection departments have improved the emissions standards and the green taxes.As a traditional small profit,the feasible and stable operational craft to get excelent water quality is needed for the pig industry.According to the problems and disadvantages for current biogas slurry treatment by biochemical system,the pHysical and chemical pretreatment technology,fundamentally change the original farm biogas slurry treatment directly using anaerobic-aerobic treatment of box,for improve the biogas slurry can improve the pretreatment method of biological sex,the mechanism of changes of organic matter after biogas slurry pretreatment,by GC-MS detection means,such as the determination of different stages of organic matter composition,analysis of organic matter composition before and after the biogas slurry treatment,biological treatment and changes of the corresponding conventional indicators do regression analysis,to study the changes of internal reasons,at the same time,the two times after the pretreatment of biogas slurry and waste water into the secondary SBR system,studies the operation process of the whole system,from system to explore the advantage bacterium group changes in system stability operation method and verify the result of organic matter composition change,on this basis,establish an economic and effective treatment.Through this topic research,makes every effort to find the solution to the depth of the biogas slurry processing problems,has importa nt theoretical guiding significance but also has a strong reference value in practical engineering.According to this work,the main conclusions are obtained as follows:?1?study the changes of the organic composition of the biogas slurry pretreatment and the improvement of biochemical,and analysis the correlation of conventional index after biogas slurry pretreatment,by applying the UFe to generate the free radicals in the coordinated pretreatment system and ultrasonic cavitation effect and shearing action to break the chain as the foundation.The results showed that UFe coordinated pretreatment mainly destroy the structure of organic matter,the long chain or hydrocarbon chain break or open loop,molecular into large,medium,small molecules,the refractory organic matter in wastewater oxidation of easily degradable organics,BOD₅/COD increased to 0.4 from 0.2 the biogas slurry,biochemical availability is improved greatly,the correlation coefficient of BOD,COD,TOC has statistically significant;?2?The mechanism of the synergy of UFe with hydrogenation dechlorination,free radicals and the reduction of iron oxide,etc.,by observing the SEM found on the surface of the iron powder particles in the UFe in collaborative system,acidic conditions in addition to the acid and the action of the zero-valent iron particles on the surface of the corrosion caused by ultrasonic cavitation high-speed erosion and cavitation?destruction of particle surface oxide la yer?,cleaning effect,such as alkaline conditions generated cavitation bubble collapse when the instantaneous effect of high temperature and high pressure,ultrasonic through erosion,cavitation,fracture,cleaning,fusion and other effects,activation and enhance the surface properties of iron powder;?3?after pretreatment,and through the UFe biogas slurry into the first stage SBR system?SBR1?in-depth processing,COD removal rate is not ideal,generally below70%,the highest removal rate less than 80%of ammonia NH3-N,dehydrogenase activity was 45.8925?TF mu g/L,activated sludge hours?,showed that the activated sludge reactor is normal,OUR 13.631 mg O₂/g MLVSS·h.Less than 25 mg O₂/g MLVSS·h,at a lower level,indicates that there are more refractory organic compounds in the water body,which leads to the unsatisfactory effect of COD and ammonia NH₃-N removal;?4?in order to improve the sewage biological sex,for the purpose of the SBR1 water with ozone?O₃?pretreatment,to control the O₃ oxidation reaction after biochemical improve before,mineralization reaction,the study found that the core role of O ₃pretreatment is the change of UV₂₅₄,O₃ is the main reason is to eliminate the UV₂₅₄O₃ and water of C=C,C=O structural responses,such as O₃ at the same time use its strong oxidizing aromatic ring of the organic matter in waste water and a double bond structure,make the organic matter of ultraviolet absorption weakened,thus resulting in a decline in UV₂₅₄ and oxidation process was made into small molecular organic macromolecular organic matter decomposition,change the molecular structure and polarity,still reserved as organic matter in water,increase the number of medium and small molecule organic compounds,water is advantageous to the next period of biochemical reaction;?5?on the basis of pretreatment of pretreatment of UFe,SBR1 and O₃,the operation of SBR2 in the two-stage SBR system was studied.After SBR1 treatment,the water is treated with ozone pretreatment to enter SBR2.The water intake COD is about 650mg/L,and the average COD outlet water is67.7 mg/L.The ammonia NH3-N was about 200 mg/L,and the average ammonia NH₃-N was 10.6 mg/L,which met the comprehensive first-level emission standard;?6?using two levels of pretreatment and two combination SBR process,the system run continuously for two months,study the stability of the system in operation process and the technical feasibility,and using the existing SBR process as the reference,in the practice of the process on the basis of the technology,investment,energy consumption and operating costs of technical economy came to the conclusion that two levels of pretreatment and the combination of the two stage SBR process and conventional SBR process of water can be even lower than the national emission standard,is technically feasible,from the perspective of investment and operation cost perspective,the two levels of pretreatment combination with two-stage SBR process is more suitable for the depth of the pig biogas slurry treatment.