Membrane fouling in a microalgal-bacterial membrane photobioreactor: Effects of P-availability controlled by N:P ratio. (November 2021)

• Record Type: Journal Article
• Authors: Zhang, Meijia; Leung, Kam-Tin; Lin, Hongjun; Liao, Baoqiang
• Is Part Of: Chemosphere. Volume 282(2021)
• Publication Date: 2021-11
• Subjects: Biomass properties -- Membrane fouling -- P-availability -- N:P ratio -- Microalgal-bacterial membrane photobioreactor; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131015
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Microalgal-bacterial membrane photobioreactor (MB-MPBR) is a promising technology to simultaneously remove organics and nutrients from wastewater. However, membrane fouling in MB-MPBR was seldom studied. In this study, potential effects of P-availability on biomass properties and membrane fouling in MB-MPBR were investigated. Under a nitrogen sufficient condition, a lower N:P ratio of 3.9:1 (P-rich) caused more severe membrane fouling. The dominant fouling mechanism was cake layer formation. Serial characterization showed a smaller particle size distribution (PSD), more free microalgae and significantly different surface composition of microalgal-bacterial flocs at N:P ratio of 3.9:1 compared with that of 9.7:1. The variations on PSD and surface composition were fully consistent with that of filtration resistance and thus considered as the primary contributors to the different fouling performance. The above results suggested that controlling microalgae/bacteria consortium in a good ratio by optimizing operating conditions is the key event for membrane fouling control in MB-MPBRs. Graphical abstract: Image 1 Highlights: Effects of P-availability on the membrane fouling of MB-MPBR was investigated. Lower N:P ratio (P-rich) led to more severe membrane fouling. Smaller PSD at lower N:P ratio was the underlying cause for faster membrane fouling. A good microalgae/bacteria ratio is the key to control membrane fouling.