Effects Of Two Kinds Of Adsorption-type Additives On Anaerobic Aigestion Of Chicken Manure And Cow Dung

With the intensive and large-scale development of China's animal husbandry,the rational disposal and resource utilization of livestock and poultry manure has become an important issue to ensure the stability of the ecological environment,energy development and protection of food safety.Anaerobic digestion is a widely used treatment technology of animal manure resource utilization.It not only solves the problem of environmental pollution,but also produces biomass energy biogas,and solves the short-term problem of fossil fuel.In this study,under simulated household biogas fermentation environment,at a constant temperature of 35±1?,chicken manure and cow dung are used as fermentation substrates.The biochar accounts for 0%,2.5%,5%,7.5%and 10%of the substrate concentration,and the n ZIV accounts for 0%,0.25%,0.5%,0.75%and 1%of the substrate concentration.Three repeated batch fermentation tests for each treatment setting.The aim is to explore the dynamic effects of adding biochar and n ZIV on the anaerobic digestion characteristics of different raw materials,to seek the optimal concentration of anaerobic digestion,and to provide theoretical and technical basis for efficient anaerobic fermentation of different raw material substrates.It's an effective method for the practical application of anaerobic fermentation.The conclusions reached are mainly as follows:?1?Adding biochar can reduce the possibility of anaerobic digestion and acidification of chicken manure,stabilize the system environment,and significantly increase the cumulative biogas production?P<0.05?.Among them,the treatment with 5%biochar added had the highest cumulative biogas production,up to 21,532 m L.Compared with the control,the cumulative biogas production of each treatment increased by 66.23%,93.96%,88.60%and 60.43%,respectively.The addition of 2.5%,5%,7.5%biochar can significantly increase the cumulative biogas production of anaerobic fermentation of cow dung?P<0.05?,of which the addition of 2.5biochar treatment has the highest cumulative biogas production,reaching 6739 m L.Compared with the amount of biogas produced,they respectively increased by 23.74%,23.57%,17.55%and decreased by 30.33%.The addition of high concentration biochar can inhibit the anaerobic fermentation of cow dung.?2?The addition of n ZIV has no effect on the cumulative biogas production of anaerobic fermentation of chicken manure.nZIV increases the system p H and keeps the p H in a higher alkaline range,thus affecting the gas production effect.The addition of 0.75%and 1%n ZIV significantly increased the cumulative biogas production of anaerobic fermentation of cow dung.The cumulative biogas production of BN1 treatment was the highest,reaching 7046 m L.Reduced by 8.04%,65.26%and increased by 16.34%,29.38%.?3?By comparing the efficiency of anaerobic fermentation gas production of two raw materials with two adsorbent additives,biochar has a significant effect on the gas production efficiency of anaerobic fermentation of two raw materials?P<0.05?.In fermentation,the optimal fermentation parameters of CB₅ treatment are the best,the cumulative cumulative gas production in the same fermentation cycle is the largest,and the fermentation gas production efficiency is the highest;in the anaerobic fermentation of cow dung,the alternative fermentation of BB_2.5 treatment is the best,the same fermentation cycle The highest cumulative biogas production and the highest fermentation gas production efficiency;due to the reduction of nitrogen content in cow dung,high-concentration biochar has an inhibitory effect on the anaerobic fermentation gas production efficiency;nano zero-valent iron additives on chicken manure anaerobic fermentation gas production efficiency There is no obvious promotion effect,and the high concentration of nano-zero-valent iron has an inhibitory effect on the gas production efficiency of anaerobic fermentation;but the appropriate concentration of nano-zero-valent iron significantly improves the fermentation effect of anaerobic fermentation of cow dung?P<0.05?.?4?Optimal dosage based on mathematical model:A quadratic curve model was used to perform nonlinear regression on the results of anaerobic fermentation of chicken manure with different concentrations of biochar,and the final fitting result was converted into the optimal biochar addition.It is 15.32 g,and the maximum cumulative biogas production is21844.75 m L.According to the prediction of the improved Gompertz model,adding 2.5%biochar to cow manure and having cumulative cumulative gas volume,reducing stagnation time and metabolic fermentation cycle and better gas production potential,so 2.5%biochar in this experiment is cow dung annoying the optimal amount of biochar added for oxygen fermentation.There is no suitable prediction model for the effect of different concentrations of n ZIV on the gas production efficiency of anaerobic fermentation of the two raw materials.?5?Dehydrogenase activity directly reflects the ability of microorganisms to degrade organic waste.The addition of n ZIV can promote DHA during the fermentation of two substrates.The DHA value is significantly greater than that of biochar treatment and control treatment.Therefore,in this experiment,n ZIV can increase the degradation and reduction capacity of anaerobic fermentation microorganisms,and provide a reference for the study of microscopic effects.