Technische Universitat Darmstadt, IWAR, Wastewater Technology, Petersenstrabetae 13, 64287 Darmstadt, Germany.
Environ Sci Technol. 2009 Nov 15;43(22):8561-5. doi: 10.1021/es901559f.
To investigate the effect of sludge retention time (SRT) and the concentration of mixed liquid volatile suspended solids (MLVSS) on oxygen transfer in activated sludge, we studied mass transfer coefficients (k(L)a) in a pilot-scale membrane bioreactor, which treated synthetic greywater. Additionally, experiments with iron hydroxide flocs were performed to examine the role of free water content in oxygen transfer. The results demonstrate that the alpha-factor is reduced when free water content decreases and floc volume increases. Because the MLVSS concentration in activated sludge mainly regulates floc volume, a reduction of oxygen transfer with increasing MLVSS concentration was observed. If the floc volume remains unchanged, oxygen transfer increases with increasing SRT.
为了研究污泥停留时间（SRT）和混合液挥发性悬浮固体浓度（MLVSS）对活性污泥中氧传递的影响，我们在一个处理合成灰水的中试规模膜生物反应器中研究了传质系数（k(L)a）。此外，还进行了氢氧化铁絮体的实验，以研究游离水含量在氧传递中的作用。结果表明，当自由水含量降低且絮体体积增加时，α 因子减小。由于活性污泥中的 MLVSS 浓度主要调节絮体体积，因此观察到随着 MLVSS 浓度的增加，氧传递减少。如果絮体体积保持不变，随着 SRT 的增加，氧传递增加。
