【作者】 钱小青；

【导师】 赵由才；

【作者基本信息】 同济大学 ， 环境工程， 2006， 博士

【摘要】 泔脚废物日益增长的产量及其环境安全影响已引起人们的普遍关注。从环境友好及废物资源化的角度，厌氧发酵技术是对其进行科学处理的较佳选择。因而，为了推进泔脚废物处理的产业化进程，进行泔脚废物厌氧发酵处理的可行性及其系统工艺研究是非常必要的。此外，氢能是未来最具潜力的可替代能源之一，随着厌氧生物产氢研究的渐渐深入，利用有机废物进行多阶段的产氢、产甲烷资源回收概念已逐步成为世界各国的共识，积极对其展开研究探索，具有重要的技术理论发展意义。 本文首先从泔脚处理迅速工程化的角度，系统的研究了泔脚的组成、脱水及酸化特性；厌氧发酵的影响因素和启动优化条件；发酵的温度、负荷、营养物、相分离的过程影响；优化工艺的扩大中型试验；沼液的农用影响等工程化必须条件参数。再根据有机废物处理的技术发展趋势，创新性进行了污泥热处理程序、矿化垃圾等多孔介质对泔脚发酵产氢的影响研究，试验探讨了矿化垃圾协同泔脚产氢的内在机制，掌握了泔脚发酵生物产氢的初步条件，取得了较高的生物氢产率。主要的研究成果如下： (1)泔脚有机物含量高，极易酸化；亲水性强，难以机械脱水，减容效果差。生物接种率、有机负荷、含水率是影响其厌氧发酵启动的主要因素；小型静态试验表明，80％接种率，90％含水率条件是泔脚废物厌氧发酵启动的最佳条件，系统产气率达到0.65L／g。良好的搅拌条件能促进甲烷化的潜力和进程，降低启动阶段的生物接种率；在70％接种率、90％含水率条件下，具有机械搅拌装置的实验室扩大试验能稳定进行，比气化率达到0.68L／g，沼气中甲烷气浓度达到50～55％之间，具有稳定的沼气化发酵特性。 (2)小型批量连续发酵表明，发酵负荷是影响发酵稳定和效率的关键因素。中温条件下，泔脚发酵的适宜负荷应介于1.00gVS／L.d左右；提高负荷，系统难以稳定启动运行；试验中，0.90gVS／L.d负荷的平均产气率达到0.56L／gVS。混合营养液的添加能促进甲烷菌的活性恢复，并一定程度刺激甲烷菌的产气活性，试验中，生物气产率提高约17％。高温发酵能促进系统的产气率及产气量，但不能提高系统的有机负荷；适宜负荷下产气量相对于中温条件提高40％左右。进行泔脚预酸化碱度调节的改进两相发酵表明，两相系统的发酵负荷和产气率相比单相系统最大能提高接近50％，发酵负荷为1.5gVS／L.d时，小试产气率达到0.9L／g(VS)。 (3)基于工程化参数研究的需要，在小型试验的基础上，进行了总容积1300L的预酸化两相连续发酵的中试设备构建设计；运行试验结果表明，在中温发酵条件下，泔脚废物的预酸化两相处理，在较优负荷1.66kg／m3.d时，废物最大停留时间为50d，每吨泔脚能产生102m~3的沼气。与城市有机废物大型发酵工艺的技术与运营指标的对比定性分析表明，本工艺条件下的泔脚厌氧发酵处置具有广阔的社会产业化应用前更多还原

【Abstract】 The quantity of food origin wastes is increasing dramatically in China cities due to the habits of Chinese and their food structures. According to the local regulations, food origin wastes cannot be used as feedstuff for livestock as it contains hazardous bacteria and virus. Anaerobic digestion is considered to be a favorable option for the effective treatment of the wastes so that methane gas and fertilizer can be produced while the wastes are stabilized. Traditionally, only methane is obtained. Biological hydrogen production from the wastes is highlighted in world using anaerobic digestion.In this work, experiments at bench and pilot scale were well conducted for food origin wastes to determine the optimum operating conditions to maximize the biogas output. Apart from that, the influences of biogas fluid from food wastes digestion on germination and sprout growth of familiar plant seeds were also investigated. The seeds used in tests were the seeds of rice- 4512, rice- 1750, wheat and cucumber- Jinyou No.1. The results showed that anaerobic digestion was an effective and promising technology for food origin wastes treatment. Further, the primary research was performed on bio-hydrogen production from food wastes for first time in China, from which some favorable harvests were acquired involved in bio-hydrogen process such as the influences of porous matter addition, aged refuse inoculums, and so on.First of all, the food origin wastes were characterized with chemical composition, dehydration behavior and acidification processing. The average water content, VS, C/N, C/P, C/Ca in the wastes was determined to be about 85%, 89%TS, 21.6, 202.8, 34.3, respectively. Plentiful microelements and little poisonous matters in the wastes would benefit for the growth of anaerobic microorganisms. It was also found that the wastes were quite difficult to be dehydrated and readily to be biologically acidified with negligible biogas production.The bench scale experiments were conducted aiming to quest for the feasibility of the anaerobic digestion for food origin wastes and find out the digestion conditions preparing for pilot scale experiments. The optimum ratios of sludge to waste food, water contents, organic load, temperature, etc., were explored in a single-phase or two-phase anaerobic digestor. The results indicated that water content should be controlled to over 90% and inoculation rate of 80% (sludge) so that anaerobic digestion can start and run successfully with a methane content of 50～55% in biogas. Meanwhile, an excellent mixing in the digestion system and a steady temperature profile was also required.更多还原