| China is a big country of the animal husbandry.with the development of large-scale intensive farms, livestock and poultry waste pollution is more and more serious, thus,reasonable removal process of animal manure and waste treatment technology will reduce the impact of waste on the surrounding environment. In order to obtain the better effect biogas anaerobic digestion, pig farms often apply deep-pit process, but the effect of different storage conditions deep-pit on its effluent anaerobic digestion is unclear. In this study, swine manure and urine were collected, and the mixture was stored under different temperatures(20℃,30℃) and storage periods(7d,14 d,21d) to produce deep-pit effluents,which be used as substrate to investigate the effects of the characteristics of deep-pit on anaerobic digestion, it can provide the basic data for applying deep-pit technique and its subsequent anaerobic fermentation biogas engineering for large-scale pig farms.(1)The analog test of deep-pit showed that: With the prolongation of the storage time, total solid content,organics ammonia nitrogen concentration in water increased, the anaerobic digestion gas production rate is lower, and the longer the storage time, the lower the biogas yield.Different storage temperature has little influence on the effluents.Carbon dioxide emissions is obviously greater than the methane emissions during the storage period of swine manure, and under the condition of high temperature storage of carbon dioxide emissions is visibly greater than the lower.(2)In the test,With the increase of TS, the anaerobic digestion cumulative gas production gradually decreased, but the difference was not significace. The anaerobic digestion treatment group nissan volume difference obvious(P < 0.05). With the increase of TS, anaerobic digestion, nissan volume is on the decline. TS, the greater the blisters dung the VS lower methane production rate. Blisters fecal material volatile solids and COD for the effect of anaerobic digestion with total solid concentration on the influence law of anaerobic digestion gas characteristics are basically identical. Concentration ofammonia nitrogen in anaerobic digestion, and the effects of gas is mainly influence on anaerobic digestion rate of producing gas. Ammonia nitrogen concentration in 2000 mg/L,the average methane production rate of 691.7 mL/gVS, ammonia nitrogen concentration is3000 ~ 4300 mg/L, the methane production rate averaged only 413.7 mL/gVS, P < 0.01).Blisters fecal material ammonia nitrogen concentration greater than 3000 mg/L to the inhibition of anaerobic fermentation increased significantly.(3)The biogas yield has been at a higher level within 7 days of anaerobic digestion in experiments,and anaerobic fermentation process has leveled off after 10 days, with the c umulative yield of biogas reaching 80% of the total yield. It is recommended that when usi ng deep-pit sewage as fermentation materials, hydraulic retention time can be adjusted tim ely according to the wastewater characteristics and related parameters, to make sure that us e resources efficiently and improve the operation efficiency of the biogas project.(4)The experimental data show that first order hydrolysis dynamic model can be used to simulate the substrate digestion and predict the cumulative methane yield;(5) Swine farm effluent anaerobic digestion monitoring results show that an anaerobic fermentation of feed material VS methane production rate is with the change of the total volatile solids in the wate. the water increases, the total volatile solid material VS methane production rate decreased; Water volatile solid volume decreases, and the material VS methane production rate increased.In July, the average water VS 1.6 ± 1.2%, the average daily VS methane production rate for 920 + 720 ml/g, methane concentrations for62 ± 2%;in December, the average water VS 2.8±0.9%, the average daily VS methane production rate was only about 750 ±330 ml/g, methane concentrations for 60±1%. |
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