铁粉/鼠李糖脂对高含固率脱水污泥的强化厌氧消化

Enhanced Anaerobic Digestion for Dewatered Sludge of High Solid Content by Dosing of Iron Powder/Rhamnolipid

改善高含固率脱水污泥的厌氧消化反应类型、提高传质效率是当前的研究热点之一。采用批次试验系统研究了铁粉和鼠李糖脂对高含固率污泥厌氧消化的强化效果,结果表明,投加铁粉和鼠李糖脂对高含固率污泥厌氧消化产甲烷均有促进作用。原污泥、投加铁粉污泥、投加鼠李糖脂污泥的日产气量分别在第4 d、第3 d、第1 d达到最大,对应的日甲烷产量分别为184、240、320 mL/(L·d)。加入铁粉后氧化还原电位(ORP)下降显著,在运行10 d后,加铁粉组的ORP最低值为-400 mV。厌氧消化过程中挥发性脂肪酸(VFA)组成以乙酸为主,投加铁粉对丙酸的产生有一定的抑制作用,加入鼠李糖脂有利于加快微生物对底物的利用速率,进而减少VFAs累积,且第10 d时VFAs的含量已下降至最低,均有利于甲烷产生。

Improvement of reaction lype and mass transfer efficiency to enhance anaerobic digestion for dewatered sludge of high solid content is one of the recent research hotspots. Enhancement of anaerobic digestion for dewatered sludge of high solid content by dosing of iron powder and rhanmolipid through batch experiment systematically was investigated. The results showed that the addition of rhan〉 nolipid and iron powder could improve the production of methane. Maximum biogas yields oeeured on the 4th, 3rad and 1st d for raw sludge, when sludge dosed with iron powder and rhanmolipid, whose daily methane productions were 184, 240 mL/（L.d） and 320 mL/（ L. d）, respectively. Addition of iron powder significantly decreased oxidation reduction potential （OItP） and the minimum ORP value of -400 mV occured on the 10th day in iron-powder group. Acetic acid was the dominant volatile fauy acid （VFA） in the whole process. Iron powder was inhibitory to the production of propionie acid and rhamnolipid could improve the microbial utilization of substrates, therefore decreasing the accumnulation of VFAs, and the content of VFAs decreased to the lowest on the 10th day, leading to the improvement of methane production.