牛粪分离液和玉米秸秆不同混合比例对厌氧发酵的影响

Biogas Production Characteristics of Anaerobic Co-digesting of the Separated Liquids of Cow Manure and Corn Straw

固液分离是我国规模化奶牛厂粪污预处理的普遍措施,将牛粪分离液与秸秆进行混合厌氧发酵产沼气是粪污处理的可行的技术途径之一。试验以中温(37±1℃),发酵总体积700 mL,接种量50%,TS 8%为发酵条件,将牛粪分离液按照不同添加量(A组0 mL、B组50 mL、C组150 mL、D组250 mL)与玉米秸秆混合进行厌氧发酵,研究不同处理厌氧发酵产沼气特性及木质纤维素降解情况。结果表明,牛粪分离液添加量为150 mL处理组发酵效果最好,累积产沼气量和累积产甲烷量最高,分别为6283 mL和2806 mL,比不添加牛粪分离液的处理组提高6.21%和24.69%,同时TS产甲烷率最高,为134 mL·g^-1,比不添加牛粪分离液的处理提高20.89%。随着牛粪分离液添加量的增加,纤维素降解率呈先上升后下降趋势,半纤维素降解率呈上升趋势,木质素降解率呈先下降后上升趋势。研究结果为牛粪分离液与玉米秸秆混合厌氧发酵工程的高效运行提供科学依据。

Solid-liquid separation was a common measure for the pretreatment of manure in large-scale dairy farms in China,anaerobic co-digesting of the separated liquids of cow manure and corn straw was an effective method to treat it.Batch experiments were adopted with fermentation volume of 700 mL,total solid(TS)of 8%,the temperature of 37℃±1℃and the inoculum of 50%.The biogas production characteristics and lignocellulose degradation of the anaerobic co-digesting of the separated liquids and corn straw was investigated,which the separated liquids addition was 0 mL(group A),50 mL(group B),150 mL(group C),250 mL(group D),each group had three parallel.The results showed that the co-digesting effective was the second to none when the separated liquids addition was 150 mL.In the circumstances,the cumulative biogas production and the cumulative methane production were the highest(6283 mL and 2806 mL,respectively),which were increased by 6.21%and 24.69%compared to the control group,and the methane production rate of TS was the greatest,134 mL·g^-1,which was increased by 20.89%compared to the control group.With the increasing of the addition of the separated liquid of cow manure,the degradation rate of cellulose increased first and then decreased,the degradation rate of hemicellulose increased all the time,and the degradation rate of lignin decreased first and then increased.The results provided scientific basis for efficient operation of anaerobic fermentation engineering that co-digesting of the separated liquids of cow dung and corn straw.