烷基糖苷联合水热预处理对污泥发酵产酸的影响

Effect of Alkyl Glycoside Combined with Hydrothermal Pretreatment on Acid Production by Sludge Fermentation

本文针对污泥中有机质水解率和酸化率低,采用烷基糖苷(APG)联合水热预处理提高有机质水解率,并且考察了其对污泥厌氧发酵产酸的影响。正交实验得到180℃、0.4 g·g^(-1) TS APG、40 min为APG联合水热预处理污泥的最佳条件;该条件下污泥溶解性化学需氧量溶出率(DDSCOD)为80%,液相中蛋白质和多糖浓度均为原始污泥的30倍以上,联合预处理更易促进有机质快速溶出;污泥的结构变得松散、多孔,有利于微生物对有机质的降解;APG联合水热预处理厌氧发酵体系提高了产酸效能,日产酸量最大为2058.35 mg COD·L^(-1),约为原泥的4.9倍。微生物群落多样性分析发现,联合预处理促进了水解菌群和产酸菌群的富集,利于有机物的水解和酸化,进而提高了挥发性脂肪酸(VFAs)产量,实现污泥的资源化利用。

In view of the low hydrolysis rate and acidification rate of organic matter in sludge,alkyl glycoside(APG)combined with hydrothermal pretreatment was used to improve the hydrolysis rate of organic matter,and the effect of the pretreatment on the acid production of sludge anaerobic fermentation was investigated.The results shown that hydrothermal pretreatment could promote the rapid dissolution of organic matter.Orthogonal experiments shown that the optimal conditions of APG combined hydrothermal pretreatment were 180℃,0.4 g·g^(-1) TS APG and 40 min.With these conditions,dissolved chemical oxygen demand dissolution rate(DDSCOD)was 80%,the concentration of protein and polysaccharide in the sludge liquid phase are more than 30 times of the raw sludge,and combined pretreatment was more likely to promote rapid dissolution of organic matter.The structure of the sludge becomes loose and porous,which is conducive to the degradation of organic matter by microorganisms.APG combined with hydrothermal pretreatment of anaerobic fermentation system can improve the acid production efficiency,and the maximum daily acid yield was 2058.35 mg COD·L^(-1),which was about 4.9 times of the raw sludge.The analysis of microbial community diversity shown that the combined pretreatment promoted the enrichment of hydrolytic bacteria and acid-producing bacteria,which is conducive to the hydrolysis and acidification of organic matter,and thus improved the yield of volatile fatty acids(VFAs),and realized the resource utilization of sludge.