污泥厌氧过程中磷释放与SMP特性研究

Characteristics of phosphorus released and soluble microbial products in anaerobic conditions of sludge

以城市污水处理厂剩余污泥为实验污泥,研究污泥厌氧过程中磷释放和溶解性微生物代谢产物(SMP)的变化特性,检测了不同厌氧时长下总磷(TP),SMP中蛋白质与多糖含量,利用三维荧光光谱与液相色谱-有机碳测定仪(LC-OCD)进一步探究了SMP的组分分布状况,应用灰色关联度分析了TP与各组分的相关性.结果表明:随着厌氧时间延长,蛋白质,多糖浓度逐渐增加,TP浓度呈现先增大后减小的趋势,TP浓度在厌氧4d最高,达到14.15mg/g VSS,说明污泥厌氧过程中存在最优释磷时间;将三维荧光光谱分为7个荧光区域,平行因子(PARAFAC)分析表明紫外光区类富里酸和类腐殖酸物质荧光强度随着厌氧时间的延长逐渐增大,微生物代谢产物的荧光强度先增大后减小;SMP中生物高聚物和腐殖酸(Humics)等大分子物质浓度逐渐增大,中分子前驱物呈现先增大后减小的趋势,而小分子物质呈现先减小后增大的趋势;蛋白质、多糖和Humics浓度与TP浓度的关联性显著.研究结果可为优化污泥厌氧释磷,提高磷回收效率提供理论支持.

This study reported the variety of total phosphorus（TP）, protein and polysaccharide of soluble microbial products（SMP） in excess sludge of anaerobic digestion process. Furthermore, the distribution of SMP components was studied by three-dimensional excitation-emission matrix spectra and liquid chromatography-organic carbon detection（LC-OCD） technology. The relationship between TP and components of SMP were also investigated by grey correlation degree. As anaerobic time went on, the concentration of protein and polysaccharide gradually increased, whereas TP concentration increased firstly and then decreased after its maximum level 14.15 mg/g VSS reached at day 4, which indicated that there was an optimal time for phosphorus release in the sludge anaerobic process. The fluorescence intensity of fulvic acid-like and humic acid-like substances increased during the anaerobic period, but the fluorescence intensity of microbial metabolites increased first and then decreased. The high molecular weight substances contained by biopolymers and humics increased gradually, the middle molecular weight substances increased firstly and then decreased while the low molecular weight organics appeared an inverse tendency. The variation of protein, polysaccharide and Humics concentration showed a significant correlation with TP release.