Study On Treatment Of Waste Water Containing HPAM With Anaerobic Baffled Reactor

Petroleum, as an important non-renewable fossil fuels, is the lifeblood of economic development. An oil field put into production, how to enhance oil recovery in highest measure, is an important problem that oil field workers have to face. With large-scale exploiting petroleum, many of oil fields in East China have entered into the stage of tertiary oil recovery. Polymer flooding as one of the most effective technique of tertiary oil recovery has been widely used. At the same time it produced a lot of waste water contained polymer. Produced water contained polymer has high viscosity; poor biodegradability and was difficult to be biodegraded. As known to all, the polyacrylamide is non-toxicity and harmless, but the acrylamide monomer produced from polyacrylamide degradation has neurotoxicity, and was determined to be a genotoxic carcinogen. Polyacrylamide in external sewage water cann't be completely degraded in the environment, create environmental pollution and potential risks to human health. Therefore, it is an important problem to be solved to insure oil fields sustainable development.The contents of this thesis were divided into six parts: the first part was literature summarization; the second part was design of experiment and method of analysis; the third part was the start-up of ABR treating waste water contains HPAM; the fourth part was study on sulfate-reducing bacteria (SRB) degrade HPAM; the fifth part was anaerobic co-substance degradation of HPAM and structure analysis of polymer after degraded; the sixth part was conclusion.In this study, the simulated waste water contains HPAM that preparated according to produced water from Gudao Zhongyi block was subject investigated. Use anaerobic biological treatment technology and select anaerobic baffled reactor (ABR) treat it. Based on the experimental results presented, the following conclusions can be drawn:1. After ABR reactor inoculated with anaerobic sludge, it took about sixty-seven days to start successfully. At the end of start-up phase, the volume load was 1.3kgCOD/m3·d, the removal rate of COD was more than 70%, the removal rate of HPAM was above 30%, and the anaerobic granular sludge was formed. By looking microbial phase and scanning electron microscope of granular sludge throughout the start-up phase. The results showed that the ABR reactor system has formed a stable microbial community structure that could degrade HPAM.2. A Sulfate-reducing bacterium that could degrade HPAM from ABR was isolated by using Culture Dish Sandwich Anaerobic Method, and it's physiological and biochemical properties were identified. The impact of environmental factors on the degradation of polyacrylamide of SBR was studied. The results showed that when the degradation time was 10 days, the pH value was 7.5; the temperature was 40℃, and the concentration of HPAM is 200mg/L. Under the above conditions, the removal rate of HPAM was above 36%. And the results showed that SRB could utilize amido in the side chain of HPAM and part of carbon in the main chain of HPAM as sole source of nitrogen and carbon respectively based on the analysis of IR before and after degradation.3. The impacts of HPAM concentration (50,100,150,200,250 mg/L) on the degradation rate were studied under single substrate and using glucose as co-substrate conditions. The results showed that under single substrate condition, when the concentration of HPAM is 100mg/L, the degradation rate was up to 60%; but under co-substrates condition, the highest degradation rate was up to 77%. At the same time, The impacts of glucose concentration (250,500,750,1000,1300 mg/L) on the degradation rate were studied, the results showed that when the concentration of glucose, the concentration of HPAM ratio was 2:1, the degradation rate of HPAM wast up to 74.6%. By using IR analysis HPAM that before and after degradation, the results showed that whether in a single substrate or co-substrate conditions, microorganisms are able to degrade HPAM and use amido in the side chain of HPAM and part of carbon in the main chain of HPAM needed for growth, but under co-substrate conditions microorganisms could degrade amino and carbon more fully than single substrates.