污泥好氧发酵过程中热解特性变化研究

Pyrolysis Characteristics during Sludge Aerobic Fermentation Process

选用脱水污泥和木块进行好氧发酵，采用热重分析仪对污泥好氧发酵过程中不同阶段的污泥进行热重分析，研究不同阶段污泥热解特性的变化，并为探索污泥好氧发酵过程中有机质的变化规律提供参考。结果表明，污泥热解过程可分为4个阶段，分别为：水分析出阶段（T1）、挥发性有机物析出转化阶段（T2）、大分子有机物转化析出阶段（T3）和矿物质分解阶段（T4）。其中挥发性有机物析出转化阶段和大分子有机物转化析出阶段为失重的主要阶段。随着发酵时间的延长，污泥的最大失重率逐渐减小。发酵第1、4、7、10、13、16天，污泥最大失重率分别为51.14%、43.50%、43.18%、39.79%、35.72%、35.46%。当堆体处于升温期时，污泥样品挥发性有机物析出转化阶段及大分子有机物转化析出阶段失重率变化较大，分别减少2.11%和4.13%；堆体温度维持在40℃左右时，污泥样品大分子有机物转化析出阶段失重率变化较大，3d内减少了4.68%。第13天与第16天污泥样品总失重率仅相差0.22%，好氧发酵在第13天已接近结束。不同发酵阶段污泥样品均以大分子有机物转化析出阶段失重率为最大，挥发性有机物析出转化阶段次之，矿物质分解阶段最小。有机质降解主要发生在发酵第1~4天和第7~10天，其中第1~4天污泥中挥发性有机物和大分子有机物均有显著降解，第7~10天以大分子有机物降解为主。

The dewatered sludge and block were used to ferment in aerobic, and the thermal gravimetric analyzer were used to analysis the pyrolysis characteristics during aerobic fermentation process, to study the pyrolysis characteristics changes of sludge in different stages, so as to provide reference to exploring the organic matter change rules in the sludge aerobic fermentation process.The results showed that the pyrolysis process divided into four stages: water analysis stage, volatile organic matter transformation stage, large molecular organic matter transformation stage and mineral decomposition stage. With the increase of fermentation process, and among which the main stages of weightlessness was volatile organic compounds precipitate phases and macromolecul-ar organic matter the precipitate phase transformation. With the increase of fermentation time, the maximum weightloss rate of sludge was decreased. The sludge maximum weight loss rate of the first day, the fourth day, the seventh day, the tenth day,the thirteenth day, the sixteenth day was 51.14%, 43.50%, 43.18%, 39.79%, 35.72%, 35.46%, respectively. When the pile maintainthe warming period, volatile organic compounds in the sludge precipitation and transformation stage of large organic moleculestransformation phase change is greatly, reduced by 2.11%, 4.13%, respectively; when the temperature of pile maintained about 40℃,sludge samples of large organic molecules transformation phase change was relatively large, reduced by 4.68% in three days. Thetotal weight loss rate of sludge samples from thirteenth days to sixteenth days was only 0.22%, which was close to the end of aerobicfermentation on thirteenth days. The weight loss rate of sludge samples was the biggest in different fermentation stages ofmacrom-olecular organic matter; the volatile organic matter was the second, and the mineral decomposition stage was the least.Organic matter degradation mainly occurred in first to fourth days and seventh-tenth days, and the volatile organic compounds and the macromolecular organic compounds had a significant degradation in first to fourth days, but the macromolecular decomposition mainly occurred in seventh to tenth days.