Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal.
Requimte/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal.
Water Res. 2014 Nov 1;64:149-159. doi: 10.1016/j.watres.2014.07.004. Epub 2014 Jul 10.
The type of carbon source present in the wastewater is one factor that affects the competition between polyphosphate accumulating organisms (PAO) and glycogen accumulating organisms (GAO) and therefore, the efficiency of the enhanced biological phosphorus removal (EBPR) process. This study investigated the impact of the carbon source composition on the anaerobic and aerobic kinetics of PAOs and the EBPR performance of an 85% PAO enrichment. When both acetate (HAc) and propionate (HPr) were present, propionate was depleted more quickly, with a constant uptake rate of 0.18 ± 0.02 C-mol/(C-mol biomass·h), while the acetate uptake rate decreased with an increase in propionate concentration, due to the substrate competition between acetate and propionate. The metabolic model for PAOs was modified to incorporate the anaerobic substrate competition effect. The aerobic rates for phosphorus (P) uptake, glycogen production and polyhydroxyalkanoates (PHA) degradation were within the same range for all tests, indicating that these rates are essentially independent of the acetate and propionate concentration, simplifying the calibration procedure for metabolic models. The metabolic model applied to describe the anaerobic and aerobic activity agreed well with the experimental data of HAc, HPr, P, PHA and biomass growth. The low glycogen consumption observed suggest that some reducing equivalents were generated anaerobically through the TCA cycle. The results of this work suggest that the propionate uptake kinetics by PAOs can provide them an advantage over GAOs in EBPR systems, even when the propionate fraction of the influent is relatively low.
废水中碳源的类型是影响聚磷菌（PAO）和糖原积累菌（GAO）竞争的因素之一，从而影响强化生物除磷（EBPR）过程的效率。本研究调查了碳源组成对 PAO 厌氧和好氧动力学以及 85% PAO 富集物 EBPR 性能的影响。当同时存在乙酸盐（HAc）和丙酸盐（HPr）时，丙酸盐会更快耗尽，其恒定吸收速率为 0.18 ± 0.02 C-mol/（C-mol 生物质·h），而由于乙酸盐和丙酸盐之间的底物竞争，乙酸盐的吸收速率随着丙酸盐浓度的增加而降低。修改了 PAO 的代谢模型，以纳入厌氧底物竞争效应。所有测试的磷（P）吸收、糖原生产和聚羟基烷酸酯（PHA）降解的好氧速率都在相同范围内，表明这些速率基本上与乙酸盐和丙酸盐浓度无关，简化了代谢模型的校准程序。应用于描述厌氧和有氧活性的代谢模型与 HAc、HPr、P、PHA 和生物质生长的实验数据吻合良好。观察到的低糖原消耗表明，一些还原当量是通过 TCA 循环在厌氧条件下产生的。这项工作的结果表明，即使进水的丙酸比例相对较低，PAO 的丙酸吸收动力学也可以使它们在 EBPR 系统中优于 GAO。
