中文摘要：

探讨了胞外聚合物对污水污泥性质的影响机制。通过γ-射线辐照和酸碱预处理，考察了活性污泥中EPS的变化；采用UV—vis光谱分析了EPS的组分变化；用重量法测定EPS的含量变化；采用红外光谱分析了不同辐照条件对EPS分子结构的影响，最后结合活性污泥处理提取EPS前后的扫描电镜观测，揭示了γ-射线辐照和酸碱预处理对EPS的影响机制。结果表明：UV—vis谱图分析表明，在2～15kGy范围内，污泥经过γ-射线辐照后，EPS含量比辐照前大幅增加，EPS在260～300nm波段出现新吸收带；红外光谱分析表明，EPS主要功能基团蛋白质、多聚糖等受辐照条件影响很大，而且上述效果在碱预处理条件下更加显著；扫描电镜结果表明，相对于酸性条件（pH值2．50），碱预处理和辐照更易使污泥絮体和细胞结构发生破坏，释放的EPS量增加。

英文摘要：

The mechanisms of extracellular polymeric substances （EPS） influencing sludge characteristics were discussed. With γ-irradiation and acid/alkaline pretreatment, changes of EPS from municipal wastewater sludge were investigated. UV-vis spectra was used to analyze the change in constituents of EPS. Weight method was used to analyze the change of EPS content. Fourier transform infrared （FTIR） spectrophotometry was used to analyze the effects of γ- irradiation and alkaline pretreatment on the functional groups in EPS. The changes of EPS were evidenced by Scanning Electron Microscopy （SEM） observation of the sludge samples before and after EPS extraction at different conditions. Results showed that, at absorhed doses from 2 kGy to 15 kGy, the extractable EPS were clearly higher. UV-vis spectra showed that, there was a new absorption band near 260 nm to 300 nm for all irradiated samples, except for at acid condition. The results of FTIR spectroscopic analysis indicated that, irradiation influenced major functional groups in EPS, such as protein and polysaccharide, and these effects were clearer when alkaline pretreatment was taken. Observation of sludge by SEM indicated that compared with acid condition （pH 2.50）, alkaline condition and γ- irradiation were more effective in making the sludge floes and cells broken.