鼠李糖脂-热对污泥厌氧发酵中脱水性能的影响

为了探究鼠李糖脂以及低温热水解预处理污泥厌氧发酵过程对污泥脱水性能的改变，利用毛细吸水时间（CST）表征脱水性能指标，有机物溶出、粒径分布以及三维荧光光谱分析阐明脱水性能变化机制.研究发现在厌氧发酵之前，预处理后污泥脱水性能均会降低；厌氧发酵之后原污泥脱水性能降低，经过热水解的污泥脱水性能改善；粒径分布变化表明粒径减小是预处理污泥脱水性能变差的部分原因，发酵之后粒径增大对于污泥脱水性能改善不明显.溶解性有机物（SCOD）、溶解性碳水化合物（SC）以及溶解性蛋白质（SP）的溶出情况发现粒径的减小是由于预处理手段对污泥的有效破解.三维荧光平行因子分析（PARAFAC）表明，污泥预处理且厌氧发酵前后溶解性有机质（DOM）均包含类腐殖酸C1（386nm/462nm）和C3（342nm/438nm）、酪氨酸类蛋白C2（278nm/306nm）以及色氨酸类蛋白C4（290nm/358nm）.其中，类腐殖酸的增多是热水解污泥脱水性能变差的主要原因，厌氧发酵之后酪氨酸蛋白的积累是原污泥脱水性能变差的原因，类腐殖酸的分解是热水解污泥发酵后改善的原因.

Effect of rhamnolipid and heat on dewatering performance of sludge in anaerobic fermentation

To explore the effect of rhamnolipid and low-temperature thermolysis on the variation of sludge dewaterability, capillary absorption time (CST) was used to quantify the alteration while particle size distribution, the content and fluorescent property of the dissolved organic matter were analyzed to understand relevant mechanism. The results showed that the dewaterability of the sludge became worse after pretreatment and anaerobic fermentation. In comparison, thermolysis and that combined with rhamnolipid could improve the dewaterability of the sludge after anaerobic fermentation. Decreased particle size contributed to worse dewaterability of the pretreated sludge, but increased particle size after fermentation presented no obvious effect on the improvement of sludge dewaterability. Dissolution of organic matter (SCOD), soluble carbohydrate (SC) and soluble protein (SP) indicates that the decrease of particle size is due to of sludge cracking. Three dimensional fluorescence with parallel factor analysis (PARAFAC) showed that before and after sludge pretreatment and anaerobic fermentation the dissolved organic matter(DOM) contained humic acid C1 (386nm / 462nm) and C3 (342nm / 438nm), tyrosine protein C2 (278nm / 306nm) and tryptophan protein C4 (290nm / 358nm). The increased content of humic acid is related to the worsened dewaterability of the thermolyzed sludge. The accumulation of tyrosine protein after anaerobic fermentation seems correlate to the adverse change of sludge dewaterability, while the decomposition of humic acid contributes partly to the improvement on the dewaterability of the thermolyzed sludge after fermentation.