Clinical Autopsy of a Reverse Osmosis Membrane Module

Frontiers in Chemical Engineering

Thomas Altmann¹  Ratul Das²  Ali Reza Behzad³  Andreia S. F. Farinha⁴  Paulus J. Buijs⁴  Szilard S. Bucs⁴  Chengyan Zhao⁴  Graciela Gonzalez-Gil⁴  Tariq Nada⁵  Johannes S. Vrouwenvelder⁶ 

[1] ACWA Power Innovation Department, Dubai, United Arab Emirates;ACWA Power Innovation Department, Thuwal, Saudi Arabia;Advanced Nanofabrication Imaging and Characterization, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia;Biological and Environmental Science and Engineering Division (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia;CTO Representative KSA, ACWA Power, Jeddah, Saudi Arabia;Faculty of Applied Sciences, Department for Biotechnology, Environmental Biotechnology, Delft University of Technology, Netherlands;

关键词: reverse osmosis;    full scale desalination plant;    membrane module autopsy;    fouling;    biofouling;    drinking water;   

DOI  :  10.3389/fceng.2021.683379

来源: DOAJ

【 摘 要 】

The desalination of seawater using reverse osmosis membranes is an attractive solution to global freshwater scarcity. However, membrane performance is reduced by (bio)fouling. Membrane autopsies are essential for identifying the type of fouling material, and applying corrective measures to minimize membrane fouling. Information from full-scale membrane autopsies guiding improved plant operations is scant in the formal literature. In this case-study, a reverse osmosis membrane from a full-scale seawater desalination plant with a feed channel pressure drop increase of about 218% over the pressure vessel was autopsied. The simultaneous determination of microbial cells, ATP, and total organic carbon (TOC) abundances per membrane area allowed estimating the contributions of biofouling and organic fouling. The abundance of microbial cells determined by flow cytometry (up to 7 × 108 cells/cm2), and ATP (up to 21,000 pg/cm2) as well as TOC (up to 98 μg/cm2) were homogeneously distributed on the membrane. Inorganic fouling was also measured, and followed a similar coverage distribution to that of biofouling. Iron (∼150 μg/cm2, estimated by ICP-MS) was the main inorganic foulant. ATR-FTIR spectra supported that membrane fouling was both organic/biological and inorganic. High-resolution SEM-EDS imaging of cross-sectioned membranes allowed assessing the thickness of the fouling layer (up to 20 μm) and its elemental composition. Imaging results further supported the results of homogeneous fouling coverage. Moreover, imaging revealed both zones with and without compression of the polysulfone membrane layer, suggesting that the stress due to operating pressure was heterogeneous. The procedure for this membrane autopsy provided a reasonable overview of the diverse contributors of fouling and might be a starting point to building a consensus autopsy protocol. Next, it would be valuable to build a RO membrane autopsy database, which can be used as a guidance and diagnostic tool to improve the management and operation of RO desalination plants.

【 授权许可】

Unknown