牛粪高浓度厌氧消化的试验研究

Study on Anaerobic Digestion of Cow Dung with the High Concentrations

高浓度物料厌氧消化容易产生酸抑制现象。试验在中温条件下,以牛粪为消化原料,通过研究厌氧消化的启动阶段及消化过程中累计产气量、原料降解率等指标的测定,分析消化浓度对物能转化量的影响。结果表明,选取活性良好的接种物,降低启动时的TS浓度(2%～5%),并增加投料次数和延长投料时间间隔,可以有效地解决酸化问题。在消化浓度为8%,且分三次进料的条件下,累计产气量和投入TS产气量最高,分别为38525 mL和0.20 m3.kg TS-1。探讨了在实际沼气工程中,当消化浓度为8%时,可将水力滞留期(HRT)控制在30～35 d;当消化浓度为10%时,可将HRT控制在35～40 d。

Anaerobic digestion with high concentrations is prone to acidification. In this paper, the effect of digestion concentration on material-energy conversion was studied with cow dung as raw material. The anaerobic start-up phase, the cumulative gas production, and material gas production rate were determined and analyzed. The result showed that the problem of acidification could be solved by selecting a higher active inoculum, reducing TS concentration （2% ~ 5% ）, in- creasing feeding frequency and feeding intervals at starting-up. In this study, the highest cumulative gas production （38525 mL） and TS gas production rate （0.20 m3 ~ kg TS-1 ） were obtained for digestion concentration of TS 8%, in which feeding was completed in three times for starting - up phase. In practical biogas project, the HRT could be controlled at 30 - 35 d for TS 8% digestion,and 35-40 d for TS 10% digestion.