中性蛋白酶水解排水管网沉积物

采用中性蛋白酶水解排水管网沉积物以缓解管网淤堵问题，考察了酶投加量、反应时间、pH、温度等对沉积物水解效果的影响，并通过EPS、三维荧光光谱以及SEM等表征分析方法探讨了可能的机理。结果表明，在酶投量为8%(质量百分数)、pH=7 、25 ℃条件下反应3 h，沉积物的水解效果较好，SCOD由原泥的259.03 mg·L⁻¹升至 6 715.40 mg·L⁻¹，多糖从14.21 mg·L⁻¹升至5 797.27 mg·L⁻¹，氨氮由23.02 mg·L⁻¹升至47.89 mg·L⁻¹，有机质含量由50.42%降至48.24%，促进了有机质从固相向液相的迁移。经中性蛋白酶水解后，沉积物的结构和EPS被破坏，内部物质溶出，溶出的多糖占主导地位，且EPS含量变化趋势为S-EPS>TB-EPS>LB-EPS。水解后上清液中微生物代谢产物与腐殖质物质增多，蛋白类(酪氨酸、色氨酸)和富里酸类物质减少。以上研究结果可为缓解管网沉积物淤堵提供参考。

Hydrolysis of drainage network sediment by neutral protease

Neutral protease was used to hydrolyze the sediment of drainage pipe network and alleviate the problem of blockage. The effects of enzyme dosage, reaction time, pH and temperature on sediment hydrolysis were investigated, and the mechanism was explored through EPS, 3D EEMs and SEM characterization.The results showed that at enzyme dosage of 8% (w/w), pH=7, 25 ℃ and 3h reaction, good sediment hydrolysis was achieved. The SCOD increased from 259.03 mg·L−1 to 6 715.40 mg·L−1, polysaccharide increased from 14.21 mg·L−1 to 5 797.27 mg·L−1, NH3-N increased from 23.02 mg·L−1 to 47.89 mg·L−1, and organic matter content decreased from 50.42% to 48.24%. This results promoted the migration of organic matters from the solid phase to the liquid phase. After hydrolyzed by neutral protease, the structure of sediment and EPS were destroyed, then the internal substances dissolved out, of which the dissolved amount of polysaccharide dominated, and the varying trend of EPS contents were S-EPS>TB-EPS>LB-EPS. After hydrolysis, the microbial metabolites and humic substances in the supernatant increased, and protein (tyrosine, tryptophan) and fulvic acid substances decreased. The results of this study provides a new method for alleviation of sediment blockage of pipe networks.