ABSTRACT: Aeration systems consume a large amount of energy in wastewater treatment plants. Fine-pore membrane diffusers are most commonly used in aeration systems. Scaling and fouling on these membrane diffusers will lead to decreased performance in aeration and increase energy consumption. This pilot-scale study focused on the scaling of the three kinds of fine-pore membrane diffusers under different influent hardness conditions. The results showed that the diffusers were mainly polluted by calcium carbonate scaling. Scaling occurred on the outer surface, orifices and inner surface of the membranes. The dynamic wet pressure (DWP) of ethylene-propylenediene monomer (EPDM), silicone and polyurethane (PU) membrane diffusers increased by 126%, 34% and 304%, respectively, within 50 days when the hardness was 400 mg/L (as CaCO3). However, the increase ratio became obviously slow during the subsequent 60-day operation, indicating a scaling rule of membrane diffusers. Considering that the standard aeration efficiency (SAE) acted as a comprehensive index for judging the aeration performance, the silicone diffuser had better performance than the other two diffusers when severe scaling occurred. This research also provides basic support for the design of membrane diffusers to improve their anti-scaling performance.

摘要: 在污水处理厂中曝气系统消耗大量的能量。微孔曝气器是曝气系统中最常用的曝气设备，然而曝气器的结垢和污染将导致曝气性能的下降和能耗的增加。本中试研究了三种微孔膜片曝气器在不同进水硬度条件下的结垢情况。结果表明，曝气器的结垢主要是碳酸钙结垢。膜的外表面、内表面和孔内均出现结垢。在硬度为400mg/L（CaCO3）条件下运行50天，三元乙丙橡胶（EPDM）、硅橡胶和聚氨酯（PU）膜片曝气器的动态湿压（DWP）分别升高了126%、34%和304%。然而，在随后的60天运行中，增长率明显变慢，表明了膜片曝气器的结垢规律。以标准曝气效率（SAE）作为衡量曝气性能的综合指标，当发生严重结垢时，硅橡胶曝气器的性能优于其他两种。本研究也为膜片微孔曝气器的设计提供了理论基础，以提高其抗结垢性能。

原载于Scientific Reports (2020 Impact Factor = 4.01)

原文链接：https://www.nature.com/articles/s41598-020-61814-5