牛粪高浓度发酵微氧脱硫过程中的含硫物质研究

针对牛粪沼气发酵进行了微氧法原位脱硫研究。对照组进行严格厌氧发酵,试验组每隔一段时间通入微量空气。试验采用两个容积7 L的发酵罐,各加入纯牛粪4 kg,牛粪的TS为14.96%,发酵温度为40℃,试验组每日通入空气量为18 mL。为分析微氧脱硫法对牛粪高浓度发酵的适用性,重点针对发酵前后发酵液中的含硫物质进行研究。试验结果表明:通入微量空气对纯牛粪发酵进行原位脱硫的平均脱硫率能够达到89.5%。在发酵过程中,含硫物质的转化是硫酸盐还原菌(SRB)和硫化物氧化菌(SOB)的综合作用,当通入空气量与发酵液内的菌群不匹配时,沼气中的硫化氢含量会发生周期性的波动。对发酵前后的发酵物进行硫平衡分析显示,微氧法脱硫后沼液中可计量的含硫物质量明显高于厌氧发酵,说明微氧法脱硫的脱硫效果较好。

Study on sulfur-containing substance in high concentration cow manure fermentation by micro-oxygen desulfurization

In this study,the in-situ desulfurization of micro-oxygen method was taken in cow manure biogas fermentation.The control groups were subjected to anaerobic fermentation,while the experimental groups were subjected to microamount air fermentation.Two 7 L fermenters were used,each added 4 kg of cow dung,the TS of cow dung was 14.96%,the fermentation temperature was 40℃,and the daily intake air volume of the fermenter for micro-oxygen desulfurization was 18 mL.The applicability of micro-oxygen desulfurization to high-concentration fermentation of cow manure was analyzed.And the sulfur-containing substances in fermentation liquor before and after fermentation were studied.The experimental results showed that the average desulfurization rate of in-situ desulfurization of pure cow manure fermentation can reach 89.5%by using trace air.In the fermentation process,the transformation of sulfur substances is the comprehensive effect of sulfate reducing bacteria(SRB)and sulfide oxidizing bacteria(SOB).When the air supply does not match the bacteria in the fermentation liquid,the content of hydrogen sulfide will fluctuate periodically.Sulfur balance analysis was carried out on the fermentants before and after fermentation,and it was concluded that the amount of sulfur content which can be measured in the biogas slurry after micro-oxygen desulfurization was obviously higher than that of anaerobic fermentation,indicating that micro-oxygen desulfurization has better desulfurization effect.