Krühne Ulrich, Henze Mogens, Larose Alain, Kolte-Olsen Anette, Bay Jørgensen Sten
Department of Chemical Engineering Building 229, Computer Aided Process Engineering Center, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Water Res. 2003 Apr;37(8):1953-71. doi: 10.1016/S0043-1354(02)00561-4.
The behaviour of a pilot scale biological phosphorus removal process (BPR) of the alternating type was investigated during periods of low influent concentrations and increased hydraulic load. A process disturbance of this type result in an increase in the phosphate concentration level in the anoxic/aerobic reactors and in the plant effluent shortly after the influent wastewater returns to normal strength. The accumulation of phosphorus in the system was avoided by the addition of an external carbon source either to the influent or to the effluent from the anaerobic reactor in form of sodium acetate. With the help of such an addition, the internal carbon storage compounds could be maintained at a high level, which is shown by poly-hydroxy-alcanoates (PHA) measurements. Several levels of acetate addition were investigated experimentally in order to determine a minimal amount of internally stored carbon, which could ensure the stabilization of BPR during such dynamic influent conditions. Furthermore reduction of aeration time during periods of low influent concentrations was investigated. It was observed that BPR was stabilized by combining a reduction of aeration time with carbon source addition, which maintained the internal stored carbon at a higher level. This combined control action resulted in a desired high BPR activity when the normal strength of the influent wastewater was re-established. The failure of the BPR process was sometimes observed even when comparatively high concentrations of PHA could be detected and an identification of a minimal PHA level was not possible. During this investigation an extended version of the activated sludge model No. 2 (ASM2), which includes denitrification by phosphate accumulating organisms, is used for the detailed analysis of the experiments. The model predicted the phosphorus build-up after the process disturbance as well as the performance during the stabilized experiments. Assisted by the model, the investigations indicate that a PHA limitation is not the only factor affecting the recovery of the BPR process during periods of low influent concentrations.
研究了交替式中试规模生物除磷工艺（BPR）在进水浓度较低和水力负荷增加期间的运行情况。这种类型的工艺扰动会导致进水废水恢复正常强度后不久，缺氧/好氧反应器以及工厂出水中的磷酸盐浓度水平升高。通过以醋酸钠的形式向进水或厌氧反应器的出水添加外部碳源，避免了系统中磷的积累。借助这种添加方式，内部碳储存化合物可以维持在较高水平，这通过聚羟基烷酸酯（PHA）测量得到了证明。为了确定能够确保在这种动态进水条件下BPR稳定运行的内部储存碳的最小量，对几个醋酸盐添加水平进行了实验研究。此外，还研究了在进水浓度较低期间减少曝气时间的情况。观察到通过将曝气时间的减少与碳源添加相结合，BPR得以稳定，这使得内部储存碳维持在较高水平。当进水废水恢复正常强度时，这种联合控制作用产生了理想的高BPR活性。即使有时能够检测到相对较高浓度的PHA，BPR工艺仍会出现故障，并且无法确定PHA的最小水平。在这项研究中，使用了活性污泥模型No. 2（ASM2）的扩展版本，该版本包括了聚磷菌的反硝化作用，用于对实验进行详细分析。该模型预测了工艺扰动后的磷积累以及稳定实验期间的性能。在模型的辅助下，研究表明PHA限制并不是影响进水浓度较低期间BPR工艺恢复的唯一因素。
