Polyhydroxyalkanoates (PHAs) are a potential substitute for traditional plastics. Synthesis of PHAs using excess sludge without additional domestication as a mixed microbial culture can reduce production costs. PHAs were synthesized using excess sludge (R1) from a continuous flow system performing simultaneous nitrification/denitrification and phosphorus removal. Excess sludge (R2) from a A2O wastewater treatment plant was used as a mixed microflora culture (MMC) and the waste fermentation liquid was used as a carbon source. Results showed that with volatile fatty acid (VFA) concentrations of 430-520 mg/L (COD of 650-750 mg/L), when R1 and R2 were reacted under anaerobic conditions, the maximum generated concentrations of PHAs were 84.41 mg/g and 30.8 mg/g, respectively. When aeration volumes were 5, 10, 15, and 20 L/h, the amounts of PHAs synthesized from R1 and R2 increased by varying degrees, with the highest amount generated at 10 L/h (108.6 mg/g and 58.58 mg/g, respectively). In the process of PHA formation, ORP shows a decreasing trend. When the concentration of PHAs reaches a maximum level, ORP drops to a "valley point." Lower ORP valley points indicate a higher potential for synthesis of PHAs. Therefore, ORP can be used as a control parameter to reflect the reaction process in the micro-oxygen synthesis of PHAs.

中文翻译：

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微氧工艺改进了未驯化过剩污泥的PHAs的合成。

聚羟基链烷酸酯（PHA）是传统塑料的潜在替代品。在不进行额外驯化的情况下，使用过量污泥合成PHAs作为混合微生物培养可以降低生产成本。使用过量的污泥（R1）从同时进行硝化/反硝化和除磷的连续流系统中合成了PHAs。来自A2O废水处理厂的过量污泥（R2）被用作混合菌群培养（MMC），废发酵液被用作碳源。结果表明，在挥发性脂肪酸（VFA）浓度为430-520 mg / L（化学需氧量为650-750 mg / L）下，当R1和R2在厌氧条件下反应时，PHA的最大生成浓度为84.41 mg / g和30.8 mg / g。当曝气量为5、10、15和20 L / h时，从R1和R2合成的PHAs的量不同程度地增加，最高生成量为10 L / h（分别为108.6 mg / g和58.58 mg / g）。在PHA形成过程中，ORP呈下降趋势。当PHA的浓度达到最大水平时，ORP下降到“谷点”。较低的ORP谷点表明合成PHAs的潜力较高。因此，ORP可以用作控制参数，以反映PHAs微氧合成中的反应过程。较低的ORP谷点表明合成PHAs的潜力较高。因此，ORP可以用作控制参数，以反映PHAs微氧合成中的反应过程。较低的ORP谷点表明合成PHAs的潜力较高。因此，ORP可以用作控制参数，以反映PHAs微氧合成中的反应过程。