The Study On Coupling Method To Extract Protein From Surplus Sludge And Its Subsequent Processing

Surplus sludge of city sewage treatment plant which without any processing and casually given away will pollute the environment seriously. Extraction of protein from the surplus sludge, fit for the purpose of sludge resources,it is one of the hot topic of current research, the coupling technology of extracting protein from surplus sludge has obvious advantages. This paper takes the sludge from Wuhan Shahu sewage treatment plant as the research object, discusses the application technology based on coupling with the heat and ultrasonic used on extraction of protein from sewage sludge, systematic analysis the temperature of reaction system, reaction time, p H value, ultrasonic output power, ultra sonic wave output time, H2O2 dosage and action time, Na2SO4 dosage such conditions respectively, this will be benefit for the future research on the extraction of sludge protein.This study can be divided into three parts: Study on the extraction process of protein based on thermal coupling; Study on the extraction process of protein based on ultrasonic coupling technology; feasibility study on sewage plant supernatant which under the optimum treatment condition as supplementary carbon source.1)The extraction rate of proteins under the action of single acid hydrolysis, hate treatment is poor, heat and acid coupled processing technology not only has high extraction rate of protein,but also the acidic environment in the course of the experiment can protect the protein in the system, hinders the Maillard reaction, shorten reaction time. In the experimental temperature of 110℃, the experimental condition of pH is about 1, the processing time for the case of 6h, the protein extraction rate can reached to 61.59%, far more than single treatment conditions.2)When the ultrasonic output power is 65%(the total power is 1200W), the ultrasonic processing time is 22 min, the protein extraction rate of single ultrasonic treatment was 62.28%, has a higher rate of extraction. Single H2O2 and ultrasonic coupling H2O2 treatment of excess sludge can extract protein, the rate of extraction were 23.56% and 59.18%, in the process of experiment, H2O2 could hydrolytic the cell wall and have an affect on the protein solution, at the end of the experiment, the remaining H2O2 will continue hydrolysis sludge and protein, it is difficult to master the experiment process. The coupling of ultrasonic and Na2SO4 process for treatment of surplus sludge, the protein extraction rate is high(reach to 69.01%), and the experimental process is easy to grasp, the end of the experiment without any factors, the liquid of experimental is clean, have no solution for further processing, the optimum processing conditions: ultrasonic outputpower of 65%, ultrasonic output time is 20 min, salt(sulfate sodium) dosage for 0.7mol/L.3) At the optimum processing condition of sludge, the supernatant can be used as supplementary carbon source for carbon and nitrogen lower sewage. The surplus sludge supernatant which under ultrasonic coupling salt treatment contains large amounts of SCOD, N and P. The supernatant treated as nutrient solution for activated sludge culture, and analysis the water quality of reactor. After study, the treated sludge supernatant SCOD removal rate reached to 68.4%, the supernatant can be used as supplementary carbon source and was used by activated sludge.