Study On Comprehensive Utilization And Treatment Of Rapeseed Process Water

The process of rapeseed oil extracted by aqueous enzymatic method produces plenty of process water, it contains a lot of water soluble protein and carbohydrate, a small count of oil and anti-nutritional factors. It will get smell and pollute the environment if it was not treated in time. The text relied mainly on fermentation by microorganism, had a preliminary study on comprehensive application and treatment of process water.First of all, to analysis and determinate main basis in the process water, it contained2.44%protein,1.6%rapeseed oil,0.4%phytic acid, free amino acid81.9mg/L, pH4.6.To Reuse the process water, determinated accumulated content of each ingredient, and compared the oil extraction rate, emulsifying degree, the quality of oil, to make a synthesize evaluation. The result shows:based on an overall consideration of various factors, the best repeated use of process water was2.Process water itself was not toxic, each organic ingredient accumulated after reuse, part of the process water could be used as feed after concentration, used yeast fermentation to degradate phytic acid, the anti-nutritional factor in the water. Selected4kinds of yeasts:Candida tropicalis, Beer yeast, K yeast, Bayberry yeast, screened by phytic acid degradation rate. The result shows:the K yeast had a better degradation effect on phytic acid than other three. Selected3factors:time, temperature, pH, each one with3levels, to design a orthogonal test, the result shows:phytic acid degradation rate could reach to87%in an optimal condition:cultural temperature32℃, pH7, cultural time36h.The rest part of process water dischargeed after treatment. Used2pretreatment methods:filtered aster heating, and adjusted pH to isoeletric point of protein, then had a filtration. The result shows:the COD degradation rates were18%and20%. The next step was biological treatment, selected from11strains of bacterium. After screening, M46and Bacillus Licheniformis were selected, mixed with K yeast. After the best inoculation proportion of mixed bacterium (1:2:2) was determined, selected fermentation time, pH, inoculum, temperature to do single factor tests, then found the optimum by orthogonal text, the result shows:COD degradation rate could reach to95%in optimal condition which was cultural temperature at30℃, pH7, cultural time36h,10%inoculum, recycled the SCP, the dry crude protein content was52%, biological treatment had a good effect on process water.