| Anaerobic digestion is the effective means of organic wastes treatment to realize its reclamation and harmless due to its characteristic of degradability and biological feasibility. But in the process of organic wastes anaerobic digestion, hydrolization is the speed-limited step of the whole digestion system because the fermentation substrates usually exist as particle form. In this paper, the regularities of hydrolization and releasing for organic wastes in two phase anaerobic digestion process with sequencing hydrolization and UASB were studied, relying on the key item of national 10th five year plan.①The regularity of hydrolization and releasing of oganic wastes in two phase anaerobic digestion process was researched. The experiment results showed that the concentration of COD and VFA in the releasing liquid and capacity of releasing liquid gradually declined while the soaking time increasing. After 8 days the capacity of releasing liquid became steady. The capacity of NH3-N in releasing liquid increases firstly and then declines. This can be ascribed to the relation between hydrolytic rate of protein and concertration of NH3-N in releasing liquid. By analyzing the solid phase components of waste, it showed that while the soaking time increasing the amount of VS, protein, total sugar in solid phase keep fixed or decline gradually, but the amount of fibrin and crude fat increase gradually. This is perhaps as a result of the different hydrolization rate between the components. By comparison, the hydrolization rate from high to the low is: total sugar, crude protein, crude fat, fribrin. In the experiment, while PH of the inflow is 7, waste particle diameter is 10~15mm, ratio of solid to liquid is 1:1, temperature is 25℃, soaking 200g organic wastes can release 12085.85mg COD and 5648mg VFA in releasing liquid respectively. The percent hydrolysis of VS, fribin, protein, total sugar, crude fat are: 73.48%, 30.37%, 70.34%, 74.85%, 61.75%.②Four influencing factor to hydolization of organic wastes which are PH, ratio of solid to liquid, temperature, particle size are researched by experiment. The experiment results showed that the effectiveness of hydrolization declines in the condition of strong acid and strong alkali due to the inhibiting effects to the microbial growth in extreme environments. Soaking the waste with neutral and alkalescent inflow (PH=7~9) can get the most effective result, and the releasing liquid with PH=5.5~7.5 is propitious to the growth of methanogenic bacteria in the next step. The hydrolization rate of organic waste increases with the ratio of solid to liquid decline. When the ratio of solid to liquid is 1:1, it is propitious to hydrolization and releasing for organic wastes and keeps the well performance of UASB reactor at the same time. When the temperature is 45℃, the effectiveness of hydrolization is the best. Excessively high or low temperature can inhibit the growth of hydrolization and acidification bacterium. Small priticle size is propitious for organic wastes hydrolization as the contacting area between liquid and waste is large. But excessively small particle size size will lead partial particle filter into the liquid and come into being SS, and thus influence the running of the system.③Based on the first order kinetic model, the first order hydrolysis model of different wastes components was created.According to the test results, the Coefficient of Dissolution of VS, cellulose, crude protein, crude fat, total sugar can be obtained by fitting. The Coefficient of Dissolution are 0.1204, 0.0292, 0.1179, 0.0811, 0.1211, respectively.④By using Logarithmic fitting mode (y = ALn(x) +B), the coefficient of variation of the dissolved quantity of each unit and time cost can be fit, and the mathematical relationship between COD dissolved quantity and the time can be obtained. y = 172.57Ln(x) + 119.18And the values of A and B in the unit VS COD Dissolved Quantity VS. Time relation formula in different pH values and different temperatures can be acquired finally.
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