Effects Of Storage Time And Solid Content On Anaerobic Fermentation Of Blisters In Piggery

With the large-scale development of pig farming,the large-scale concentrated discharge of piggery waste is a serious threat to the environment,ecology and human health.In the large-scale pig farms,the transfer and slaughter of live pigs have periodical storage and discharge of vesicular excrement in the piggery storage tanks,and the seasonal water use difference also leads to the content of vesicular excrement total solids?TS?.Significant changes.Therefore,studying the characteristics of greenhouse gas emissions within the vesicular storage cycle and its effect on the subsequent methane fermentation efficiency is of great significance for the reduction of greenhouse gas emissions and the improvement of methane fermentation efficiency.This paper aims to reduce greenhouse gas emissions and increase energy conversion rate.The effects of storage time and TS on the anaerobic fermentation process of blisters are comparatively studied.The appropriate blisters storage and emission cycle and the appropriate concentration of TS for methane fermentation are determined.Provide guidance for the management of pig houses and the design and operation of blisters anaerobic fermentation engineering.Simulation of pig manure vesiculation process,static fermentation test,storage time and TS in the vesicular excrement storage process,the main pollutant conversion and greenhouse gas emissions characteristics.The results showed that during the storage of vesicular excrement,the degradation of organic matter mainly occurred in the first 14 days.The concentration of SCOD,TP,NH₄⁺-N and VFAs increased with time and reached a peak value,and remained relatively stable afterwards;with blisters With the increase of manure TS,the production of SCOD,TP,NH₄⁺-N,and VFAs increased significantly.The length of the blisters storage time affected CH4 and CO2 emissions more than TS,and the CO2 emission flux was much greater than CH4.The longer the emission flux,the longer the storage time,the greater the emission of CO2 and CH4.With the increase of TS,the emission flux of CO2 is greater,and the emission flux of CH4 is showing a downward trend.Longer storage time and lower TS are more conducive to methane fermentation and contaminant removal of blisters,and the effect of storage time is significantly greater than that of TS.For blisters with storage time of 28 d and TS of 3%,the cumulative methane production and specific methane production rates were up to 3.02 L/L and 0.13 L/L/d,respectively,and the removal rates of dissolved COD and volatile solids were respectively Reached 63% and 55% respectively.For blisters with a storage time of 14 days,the lower p H caused by the accumulation of volatile fatty acids severely inhibited the growth and metabolism of acetogenic bacteria and methanogens,which were the main factors limiting the performance of methane fermentation.The length of the storage time will significantly affect the microbial community structure in the storage stage of blisters,but it has little effect on the microbial community structure in the stage of methane fermentation.The predominant flora of vesicular excrement is intestinal bacteria and Brevibacterium methane.The predominant microflora in the final communities formed during storage are the hydrolytic fermentation flora and the Methanosphaeroides.The resulting communities formed during the methane fermentation process produce acetogens and methane filaments for hydrogen production.Bacteria occupy a dominant position.The predominant species in storage and methane fermentation are mainly Clostridium sensu stricto,Ignatzschineria,Lactobacillus,Terrisporobacter,and clumps.Comanonas et al.,and the dominant methanogens are Methanothrix,Methanobrevibacter,and Methanosphaera.