Abstract:

In recent years, with the emergence of resource shortages and environmental pollution, the research on the recovery and utilization of surplus sludge protein has received extensive attention. This paper focused on the study of the influence of the content of extracellular polysaccharides on the dissolved sludge protein and the hydrolysate solid-liquid separation by the alkaline-thermal hydrolysis method, and the preliminary analysis of its influence mechanism was carried out. The results showed that the increase in the content of extracellular polysaccharides had a significant inhibitory effect on the protein dissolution of the remaining sludge, and at the same time, the solid-liquid separation performance of the hydrolysate deteriorated. When the mass fraction of extracellular polysaccharide was 350mg/gTS, the dissolution rate of protein was 29.62%, the mass fraction of DNA in the hydrolysis residue was 233.33mg/gTS, the volume of the filtrate was 23.60mL, and the viscosity of the hydrolysate was 545.33mPa·s. Excitation emission matrix spectra and confocal laser scanning microscopy showed that with the increase of extracellular polysaccharide content, the Maillard reaction between polysaccharide and protein intensifies, and the area coverage of polysaccharide increased, which were not conducive to the dissolution of sludge protein.

Key words: extracellular polysaccharide, excess sludge, alkaline thermal hydrolysis, protein dissolution, solid-liquid separation, waste treatment

摘要：

近年来，随着资源短缺及环境污染问题的凸显，剩余污泥蛋白质的回收利用研究受到了广泛关注。本文重点研究了胞外多糖含量对碱热水解法溶出污泥蛋白质及水解液固液分离性能的影响，并对其影响机制进行了初步分析。结果表明，胞外多糖含量的增加对剩余污泥蛋白质溶出有明显的抑制作用，与此同时，水解液的固液分离性能恶化。当胞外多糖含量为350mg/gTS时，蛋白质的溶出率为29.62%，水解残渣中的DNA含量为233.33mg/gTS，滤液体积为23.60mL，水解液的黏度为545.33mPa·s。三维荧光光谱法和共聚焦扫描显微镜观察发现，随着胞外多糖含量升高，多糖与蛋白质类物质间的美拉德反应加剧，多糖的面积覆盖率升高，这些均不利于污泥蛋白质的溶出。

关键词: 胞外多糖, 剩余污泥, 碱热水解, 蛋白质溶出, 固液分离, 废物处理