King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
Water Res. 2019 Mar 1;150:1-11. doi: 10.1016/j.watres.2018.11.054. Epub 2018 Nov 21.
Biofouling severely impacts operational performance of membrane systems increasing the cost of water production. Understanding the effect of critical parameters of feed water such as biodegradable substrate concentration on the developed biofilm characteristics enables development of more effective biofouling control strategies. In this study, the effect of substrate concentration on the biofilm characteristics was examined using membrane fouling simulators (MFSs). A feed channel pressure drop (PD) increase of 200 mbar was used as a benchmark to study the developed biofilm. The amount and characteristics of the formed biofilm were analysed in relation to membrane performance indicators: feed channel pressure drop and permeate flux. The effect of the characteristics of the biofilm developed at three substrate concentrations on the removal efficiency of the different biofilms was evaluated applying acid/base cleaning. Results showed that a higher feed water substrate concentration caused a higher biomass amount, a faster PD increase, but a lower permeate flux decline. The permeate flux decline was affected by the spatial location and the physical characteristics of the biofilm rather than the total amount of biofilm. The slower growing biofilm developed at the lowest substrate concentration was harder to remove by NaOH/HCl cleanings than the biofilm developed at the higher substrate concentrations. Effective biofilm removal is essential to prevent a fast biofilm regrowth after cleaning. While substrate limitation is a generally accepted biofouling control strategy delaying biofouling, development of advanced cleaning methods to remove biofilms formed under substrate limited conditions is of paramount importance.
生物污垢会严重影响膜系统的运行性能，增加水生产的成本。了解进水关键参数（如可生物降解基质浓度）对所形成生物膜特性的影响，有助于开发更有效的生物污垢控制策略。在这项研究中，使用膜污垢模拟器（MFS）研究了基质浓度对生物膜特性的影响。以 200 mbar 的进料通道压降（PD）增加作为基准，研究了所形成的生物膜。分析了形成的生物膜的量和特性与膜性能指标之间的关系：进料通道 PD 和渗透通量。评估了在三种基质浓度下形成的生物膜的特性对不同生物膜去除效率的影响，应用了酸碱清洗。结果表明，较高的进水基质浓度导致生物量增加、PD 增加更快，但渗透通量下降更低。渗透通量下降受生物膜的空间位置和物理特性影响，而不是生物膜的总量。在最低基质浓度下生长较慢的生物膜比在较高基质浓度下生长的生物膜更难通过 NaOH/HCl 清洗去除。有效去除生物膜对于防止清洗后快速生物膜再生至关重要。虽然基质限制是一种普遍接受的生物污垢控制策略，可以延迟生物污垢的形成，但开发先进的清洗方法以去除在基质限制条件下形成的生物膜至关重要。
