摘要
为优化猪粪厌氧消化总固体质量分数(total solid,TS),以猪粪为原料,采用批式试验方法,研究不同TS对厌氧消化产气性能的影响。结果表明:底物固体质量分数分别为3.0%、7.5%、12.0%和15.0%时,猪粪的挥发性物质(volatile solid,VS)沼气产率随底物固体质量分数的增加而降低,分别为579、527、356和237 m L/g,底物固体质量分数为3.0%和7.5%时的CH4产率优于其他固体质量分数,分别为317和326 m L/g,占理论CH4产率的66.9%和68.8%;不同固体质量分数厌氧消化过程中,最高产CH4速率分别为37.0、24.4、10.4和4.7 m L/(g·d);固体质量分数为7.5%时消化体系的TS、VS降解率最高,分别达到49.2%和65.5%;固体质量分数为3.0%和7.5%的厌氧消化过程符合一级动力学方程,但猪粪的产甲烷速率常数从0.126 d-1下降到0.063 d-1;与3.0%的固体质量分数相比,消化时间为30 d时,底物的生物转化产CH4效率随固体质量分数的增加分别降低6.3%、55.8%和74.7%,固体质量分数为3.0%和7.5%时生物转化产CH4效率达到58.0%所需的时间分别为18和30 d。
Anaerobic digestion was a suitable technology for agricultural waste management as it combined waste treatment, energy output and recycling of by-product which can be used in agriculture as nutrient. The total solid（TS） or organic loading rate, hydraulic retention times and others parameters will influence the performance of anaerobic digestion. Among of these factors, TS was an important factor which influenced the biogas production efficiency, characteristics of the digested and the economic benefits of biogas plants because the appropriate TS can improve the utilization efficiency of working volume and increase the volume biogas production of the reactors. In order to optimize the total solid of anaerobic digestion with swine manure, batch experiment was carried out to investigate the effects of different TS contents on anaerobic digestion at TS of 3.0%, 7.5%, 12.0% and 15.0% under mesophilic conditions（35℃）. In the period of 62 d, the accumulative biogas production, volume percentage of CH4 in biogas, TS and VS, p H value before and after digestion were monitored. The biogas production and methane yields were key indicators which were used to evaluate the anaerobic digestion, and the first-order kinetic was used to model the anaerobic digestion process. The results showed that the biogas yields basing on VS decreased with total solids fraction increasing from 3.0% to 15.0% and the biogas yields were 579, 527, 356 and 237 m L/g. The CH4 yields at different solids fraction were 317, 326, 222 and 140 m L/g, respectively. The CH4 yields of 3.0% and 7.5% accounted for 66.9% and 68.8% of the theoretical methane productivity（474 m L/g） which was calculated by the protein, fat and carbohydrate content in swine manure. The maximum CH4 production rate of different TS appeared at 2 d, the values were 37.0, 24.4, 10.4 and 4.7 m L/（g·d）, respectively and the CH4 production rate during the experiment decreased with the increasing of TS generally. The volume percentage of CH4 in biogas was between 67% and 74% after 22 d, the value of solids fraction at 15.0% was the lowest. TS and VS degradation efficiency of anaerobic digestion decreased with the increasing of solids fraction from 7.5% to 15.0%, TS and VS degradation efficiency at TS of 7.5% were 49.2% and 65.5%, but that of TS at 15.0% were 37.4% and 46.9%. The VS degradation efficiency at TS of 3.0% was lower than that of the others mainly attributed to the TS content in inoculum. The first-order kinetic was used to simulate the anaerobic digestion process of swine manure at different TS contents, the results indicated that it was suitable for modeling the digestion when the solids fraction were 3.0% and 7.5%, and the degradation rate constants were 0.126 and 0.063 d-1. The first-order kinetic was not fitting well for the TS content of 12.0% and 15.0%, this can be explained that there were obvious lag phase in anaerobic digestion at high total solids fraction, the other reasons were the accumulation of intermediate product such as volatile acid（VFA） or ammonia nitrogen which resulted in the inhibition for methanogens. Compared with total solids fraction of 3.0%, the biodegradability（BAD） of swine manure at 30 d decreased by 6.3%, 55.8% and 74.7%, the methane production ratio（MPR） decreased by 8.8%, 36.9% and 42.6% with the increasing of total solids fraction from 3.0% to 15.0%. The time BDA achieved at 58.0% needed were 18 and 30 d when the total solids fraction were 3.0% and 7.5%. At the end of this experiment, BAD of different TS content were 66.9%, 68.8%, 46.8% and 29.5%, respectively.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2014年第24期246-251,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(51008163)
"十二五"国家科技支撑计划课题(2012BAD15B02)
作者简介
杜连柱，男，辽宁铁岭人，副研究员，博士，研究方向为农业废弃物资源化处理与利用。天津农业部环境保护科研监测所，300191。Email：dulianzhu99@163．com
通信作者：张克强，男，湖北武穴人，研究员，博士，主要从事农业废弃物资源化处理与利用研究。天津农业部环境保护科研监测所，300191。Email：kqzhang68@126．com
