Waste activated sludge pretreatment is indispensable as sludge hydrolysis is limited during anaerobic fermentation. In this study, a new pretreatment method by adding formic acid has been proposed to improve carbon recovery from waste activated sludge. With formic acid addition, carbon was recovered as methane or/and volatile fatty acids and the recovery efficiency was higher than HCl pretreatment at the same concentration. The highest carbon recovery efficiency (almost 40%) was shown in the group of 0.1 mol/L formic acid pretreatment which might be attributed to isoelectric-point pretreatment. That was, the produced methane with the purity of 80% and little volatile fatty acids were detected with 0.1 mol/L formic acid pretreatment. However, the carbon recovery efficiency did not increase with the increasing acids concentration. Thus, 0.1 mol/L formic acid was regarded as the optimum pretreatment approach for anaerobic fermentation of waste activated sludge. The results of microbial communities showed that enrichment of hydrogen-producing bacteria Petrimonas and hydrogenotrophic methanogens was triggered, and then might improve carbon recovery from waste activated sludge.

由于厌氧发酵过程中污泥水解受到限制，因此废活性污泥预处理是必不可少的。在这项研究中，提出了一种添加甲酸的新预处理方法，以提高废弃活性污泥的碳回收率。添加甲酸后，碳以甲烷或/和挥发性脂肪酸的形式回收，回收效率高于相同浓度的HCl预处理。在0.1 mol/L甲酸预处理组中表现出最高的碳回收效率（近40%），这可能归因于等电点预处理。即在0.1 mol/L的甲酸预处理下，生成的甲烷纯度为80%，挥发性脂肪酸很少。然而，碳回收效率并未随着酸浓度的增加而增加。因此，0。1 mol/L甲酸被认为是废弃活性污泥厌氧发酵的最佳预处理方法。微生物群落结果表明产氢菌富集Petrimonas和氢营养产甲烷菌被触发，然后可能会提高废弃活性污泥的碳回收率。