Lü F, He P J, Hao L P, Shao L M
State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Water Sci Technol. 2008;58(8):1637-43. doi: 10.2166/wst.2008.511.
Two trials were established to investigate the effect of recycled effluent on hydrolysis during anaerobic co-digestion of vegetable and flower waste. Trial I evaluated the effect by regulating the flow rate of recycled effluent, while Trial II regulated the ratio of hydrolytic effluent to methanogenic effluent, which were recycled to hydrolysis reactor. Results showed that the recirculation of methanogenic effluent could enhance the buffer capability and operation stability of hydrolysis reactor. Higher recycled flow rate was favourable for microbial anabolism and further promoted hydrolysis. After 9 days of hydrolysis, the cumulative SCOD in the hydrolytic effluent reached 334, 407, 413, 581 mg/g at recycled flow rates of 0.1, 0.5, 1.0, 2.0 m3/(m3 x d), respectively. It was feasible to recycling a mixture of hydrolytic and methanogenic effluent to the hydrolysis reactor. This research showed that partially introducing hydrolytic effluent into the recycled liquid could enhance hydrolysis, while excessive recirculation of hydrolytic effluent will inhibit the hydrolysis. The flow ratio 1:3 of hydrolytic to methanogenic effluent was found to provide the highest hydrolysis efficiency and degradation rate of lignocelluloses-type biomass, among four ratios of 0:1, 1:3, 1:1 and 3:1. Under this regime, after 9 days of hydrolysis, the cumulative TOC and TN in the hydrolytic effluent reached 162 mg/g and 15 mg/g, the removal efficiency of TS, VS, C and cellulose in the solid phase were 60.66%, 62.88%, 58.35% and 49.12%, respectively. The flow ratio affected fermentation pathways, i.e. lower ratio favoured propionic acid fermentation and the generation of lactic acid while higher ratio promoted butyric acid fermentation.
开展了两项试验，以研究循环废水对蔬菜和花卉废弃物厌氧共消化过程中水解的影响。试验一通过调节循环废水的流量来评估其影响，而试验二则调节水解出水与产甲烷出水再循环至水解反应器的比例。结果表明，产甲烷出水的循环可以增强水解反应器的缓冲能力和运行稳定性。较高的循环流量有利于微生物合成代谢，并进一步促进水解。水解9天后，在循环流量分别为0.1、0.5、1.0、2.0 m³/(m³·d)时，水解出水中累积溶解性化学需氧量（SCOD）分别达到334、407、413、581 mg/g。将水解出水和产甲烷出水的混合物再循环至水解反应器是可行的。该研究表明，将部分水解出水引入循环液中可增强水解，而水解出水的过度再循环会抑制水解。在0:1、1:3、1:1和3:1这四个比例中，发现水解出水与产甲烷出水的流量比为1:3时，木质纤维素类生物质的水解效率和降解率最高。在此条件下，水解9天后，水解出水中累积总有机碳（TOC）和总氮（TN）分别达到162 mg/g和15 mg/g，固相中的总固体（TS）、挥发性固体（VS）、碳和纤维素的去除效率分别为60.66%、62.88%、58.35%和49.12%。流量比影响发酵途径，即较低的比例有利于丙酸发酵和乳酸生成，而较高的比例则促进丁酸发酵。
