C/P对EBPR系统PAOs与GAOs竞争及PHAs代谢过程影响研究

以富含聚磷菌(PAOs)活性污泥为基础,基于FISH技术研究了SBR工艺不同C/P(25∶1、20∶1、15∶1和10∶1)对EBPR系统中功能菌变化特征与微生物胞内聚合物(PHAs)代谢过程的影响.结果表明,经过10 d运行处理,C/P分别为25∶1、20∶1和15∶1系统磷酸盐去除率88%,而C/P为10∶1系统磷酸盐的去除率为0%.FISH检测结果显示,随着C/P从25∶1下降到10∶1,EBPR系统中PAOs的含量相应从(76.42±1.24)%减少到(10.40±0.97)%,而聚糖菌(GAOs)则从(16.36±3.41)%增加到(34.25±2.59)%.在厌氧段,不同C/P条件下EBPR系统中PHB和PHV的合成动力学系数大小分别为K25∶1K20∶1K15∶1K10∶1和K15∶1K20∶1K25∶1K10∶1.随着C/P从25∶1下降到10∶1,合成PHB在PHAs中所占的比例从85%下降到24%,而PHV则从15%上升到76%;在好氧段,不同C/P系统消耗PHB和PHV的动力学系数大小均为K20∶1K25∶1K15∶1K10∶1,且C/P为25∶1、20∶1和15∶1时系统消耗主要成分是PHB(占PHAs 71%～75%),而C/P为10∶1时系统消耗主要成分是PHV(占PHAs 71%).由此表明,随着C/P的降低,EBPR系统内GAOs增加而PAOs减少,从而导致系统内PHB合成与消耗比例逐渐减少,而PHV合成与消耗比例逐渐增加.

Effects of C/P on the Competition Between PAOs and GAOs and PHAs Metabolism in EBPR System

Based on accumulating enrich phosphorus accumulating organisms (PAOs) in activated sludge and by fluorescence in situ hybridization (FISH) technique, the effects of C/P (25: 1, 20: 1, 15: 1 and 10: 1) on flora changes and polyhydroxyalkanoates (PHAs) metabolism in enhanced biological phosphorus removal (EBPR) system were systematically studied. The results show that after 10 days treatment (acetate as carbon source), the systems with C/P of 25: 1, 20: 1 and 15: 1 have good phosphate removal rate (> 88%); while for C/P of 10: 1 system, the phosphate removal rate was 0%. FISH results showed that the content of PAOs decreased from( 76.42 +/- 1.24) % to (10.40 +/- 0.97) % with C/P decreasing from 25: 1 to 10: 1, while glycogen accumulating organisms (GAOs) increased from (16.36 +/- 3.41)% to (34.25 +/- 2.59)%. In various C/P systems in the anaerobic, the production kinetic coefficients of PHB and PHV were K25: 1 > K20: 1 > K15: 1 > K10: 1 and K15: 1 > K20: 1 > K25: 1 > K10: 1, respectively. The PHB production in the proportion of PHAs decreased from 85% to 24%, while PHV increased from 15% to 76% with C/P decreasing from 25: 1 to 10: 1. For various C/P systems in the aerobic phase, their consumption kinetic coefficients of both PHB and PHV were K:20: 1 > K25: 1 > K15: 1 > K10: 1. PHB (the proportion of PHAs is 71% -75%) was the main consumption component in C/P of the 25: 1, 20: 1 and 15: 1 systems; while PHV(the proportion of PHAs is 71%) was the main consumption component in C/P of 10: 1 system. It is suggested that an increases of GAOs and decreases of PAOs in the EBPR system lead to the decreasing of PHB production and consumption, and to the increasing of PHV.