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Anaerobic fermentation to produce biogas process of crop straws in accordance with the conversion process can be divided into the hydrolysis acid production phase and methanogenic phase. Study of Vieitez and Nopharatana shows that the solid organic acid hydrolysis rate is lower than the rate of methane production, which is the rate-limiting step of anaerobic fermentation of solid organic matter. Thus two-phase anaerobic hydrolysis acid production has become the focus of the study. Combined with straw biogas engineering is facing the countryside and farmers, project investment and operation cost is the important factor to determine whether the technique is feasible. with the development of modern, mechanized collection of straw has become the premise of straw resources utilization, mechanical compactness increased significantly after collecting straw, which is not clear to impact on subsequent anaerobic biological gas of straws.The temperature is an important aspect of the microbial activity, and thus affect the hydrolysis acid yield rate of wheat straw.Therefore, we carried out the acid hydrolysis to produce properties of different compaction straws under different temperature conditions, three processing methods of straws:bundling, compaction, osteoporosis (TS concentrations were5.88%,3.77%,2.30%), respectively, at three different temperatures of10,20,30℃, analyzed pH value, solution organic matter content in liquid water, fluid volatile fatty acid production of the hydrolysis process of the wheat straw. the results show that the temperature is important influence factors of straw hydrolysis rate and the hydrolysis rate,so the hydrolysis temperature should be increased in biogas project;After being stable of hydrolysis acidification, water solution in fermentation tank respectively sets emptying,1/2,1/3of dealings, and then with the same amount of biogas slurry added to the fermentation tank to promote the further hydrolysis of straw. Test runs73d,4dischargings.In the process of hydrolysis, pH, COD, SCOD, VFAs were analyzed matter in hydrolysis process and dry matter, cellulose, hemicellulose, lignin content changes before and after hydrolysis of straw. The results show that the whole quantity of discharging is more advantageous to straw hydrolysis acidification. COD of straw dry matter yield were increased by32%and43.48%than1/2andl/3respectively. Straw dry matter loss rate were increased by42.86%and100%than1/2and1/3respectively. To maintain a higher concentration of COD solution is not conducive to the acid hydrolysis of straw.Combined with the previous test, liquid is stable in the straw hydrolysis hydrolysis after the platoon, improve the degradation rate of straw. In this experiment reflux hydrolysate bundling wheat straw effects are systematically studied, hydrolysis settings do not cycle,1days a cycle,3days a cycle of different recirculation frequency effect on wheat straw to produce acid and gas, studied the physicochemical properties and structure wheat straw before and after hydrolysis fermentation pH, COD, VFA, gas production, methane content, fermentation, the results indicated that:the cyclic treatment has a significant influence on wheat straw hydrolysis and acidification,3days a cycle COD emissions compared to1days in a cycle and not circulation treatment increased14.40%,20.24%. Circulation is conducive to the promotion of organic matter in the straw digestion, but too often the cycle will curb acid-producing bacteria activity, reduces the ability of acidified hydrolysis acid-producing bacteria.In order to study the effects of mixed hydrolysis on hydrolysis and acidification of baled wheat straw, the characteristic that hydrolysis acid production mixed by manure, food waste and vegetable waste with straw respectively. The pH value, COD, SCOD and VFAs were analyzed during the experiment process. The results showed that, either wheat straw hydrolyzed alone or hydrolyzed with other organic waste, the appropriate output time was during3-7d. And the COD content decreased after7days reaction. Mixed vegetable waste with wheat straw, the pH value of hydrolysis liquid reduced amplitude was maximum as the toatal organic acid concentration was the highest, the pH was5.31as lowest, the organic acid up to6.46g/L, and the SCOD content were the maximum. Addition with the pig manure evidently promote the wheat straw hydrolysis of organic matter dissolved, the unit dry matter rate of hydrolysis and the rate of acid production were increased by43%-134%and50.53%than the control, but the hydrolysate SCOD content, TVFA content, declined hydrolysate pH were not as good as vegetable waste. And the effect of the food waste was between pig mmanure and vegetable. From the promotion of wheat straw hydrolysis acid production point of view, to adding pig manure effect best.
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