| To achieve the comprehensive utilization of bean products wastewater, improve the utilization rate of soybean resources, extend the industrial chain of traditional bean product and reduce the emissions of high concentration organic wastewater, this paper mainly studied the separation and purification of three kinds of functional components from soybean slurry water(soybean whey protein, soybean isoflavone and soybean oligosaccharides).Evaluation of protein recovery,total sugar transmission, soybean isoflavone transmission and ultrafiltration membrane flux,using flocculation and ultrafiltration preliminarily separated protein, oligosaccharides and isoflavone in bean products wastewater. The optimum condition was that : 0.3mg/m L chitosan was used in flocculation, while 10 k Da polyether sulfone membrane was used in ultrafiltration.Protein recovery rate reached 76.1%, total sugar transmission rate reached 76%, soybean isoflavone transmission reached 77.2%, and the average flux was 18.9L/m2·h-20L/m2·h. The purity of the protein after flocculation and ultrafiltration was 50.7%.Using alkali-solution and acid-isolation purified protein. Evaluation of alkali-soluble p H, ratio of solid to liquid, extraction time,extraction temperature and acid precipitation p H optimized protein purification process.The results showed that : When the alkali-soluble p H was 9, ratio of solid to liquid was 1:20, extraction temperature was 40℃,extraction time was1.5h,and acid precipitation p H was 3.7,after 10000r/min centrifugal protein precipitation rate reached 89.8%. The protein yield was 75.5%. The purity of the protein after purification reached 90.5%, while the ash was 3.76%.Using ethyl acetate extraction and macroporous resin adsorption,soybean isoflavone was extracted from soybean products wastewater.Comprehensively considering the factors of extraction rate, desorption rate, operating cycle and the processing capacity, the best extraction process was as follows: dynamic adsorption with AB-8 resin,filling resin height 100 mm in ф16*150mm chromatography column,loading amount 180 m L in the speed of 1.2m L/min; elution flow rate 0.6m L/min, successively eluting with 10% ethanol1 BV, 40% ethanol 1BV and 80% ethanol elution 2BV.Under the optimal conditions,the extraction rate was 69.7%,while the eluting ratio and The total recovery rate of soybean isoflavone were 59.6% and 85.5% respectively in 40% and 80% ethanol eluton liquid. Using acetone extraction and ethanol recrystallization purified soybean isoflavone,of which purity was 22.4%. The optimum condition was that : Adding 200 m L acetone at acetone boiling point(55 ℃)for 1h to 5g soybean isoflavone extracts each time, after 4 times the extraction rate of soybean isoflavone reached 92.6%;Using absolute ethanol to recrystallize soybean isoflavone, soybean isoflavone purity reached 89.2%, and the rate of recovery was 26.1%.Taken macroporous resin-active carbon as decolorant,evaluation of total sugar holding rate and de-coloration rate,the optimum decolorization process of wastewater after ultrafiltration was studied.The results showed that :Filling AB-8 resin in glass column with diameter 16 mm to the height of 100 mm,while the resin bed volume was 20.1m L,the feeding rate was 1.2m L/min, and the loading amount was 180 m L,the de-coloration rate reached 83.8%,total sugar holding rate reached 79.0%.Comparison of Anion exchange resin series desalination and mixed bed desalting process, evaluation of desalination rate and total sugar holding rate, the optimum desalting process was as follows: Using mixed bed process for desalination of decoloring wastewater,employing glass column with diameter of 20 mm, while the filling height was100 mm, the mixed bed volume was 31.4m L, the volume ratio of cation to anion in mixed bed was 2:1, the feeding rate was 3m L/min, and the loading amount was 120 m L(3.82BV),the desalination rate reached 96.3%, and the total sugar holding rate was 61.1%. |
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