微量元素强化污泥和油脂厌氧共消化生物产气

Simulated Digestive Gas Production from Sludge and Grease Anaerobic Co-digestion by Trace Element Addition

在序批式厌氧反应器中比较了污泥单独发酵,污泥+油脂,污泥+油脂+微量元素发酵生物气的产量及甲烷的含量并探究了微量元素对污泥和油脂共消化产甲烷的影响。实验结果表明微量元素的投加能够显著提高生物气的产量,并且产量为243 mL/g挥发性悬浮固体(VSS),是空白组的1.3倍。然而对甲烷的体积分数作用不明显。微量元素的存在能够提高水解和酸化过程,为产甲烷菌提供更多的消化基质。进一步研究发现,微量元素能够减少污泥和油脂共消化过程中长链脂肪酸的积累,减缓了长链脂肪酸对产甲烷菌的抑制影响。

Comparisons of the yield of biogas and the content of methane among sludge sole anaerobic digestion,sludge + lipids and sludge + lipids + trace elements anaerobic digestion in the sequencing batch reactor were conducted. The experimental results show that the addition of trace elements can significantly increase the yield of biogas,and the yield is 243 mL/g volatile suspended solids( VSS),which is 1. 3 times of that in blank,however,the change of volume fraction of methane was not obvious. The presence of trace elements enhanced the processes of hydrolysis and acidification,thereby provided more digestive substrates for the production of methane. Further studies have found that trace elements reduced the accumulation of long chain fatty acids in the co-digestion of sludge and lipids,and slowed down the inhibitory effect of long chain fatty acids on the methanogens.