Issue 2, 2021

Effects of NaClO shock on MBR performance under continuous operating conditions

Abstract

In situ chemical cleaning with sodium hypochlorite (NaClO) is frequently employed to maintain a constant permeability in membrane bioreactor (MBR) systems. In this study, the effects of NaClO shock on MBR performance under continuous operating conditions were investigated. A lab-scale MBR was operated for three runs with in situ chemical cleaning. Experimental results demonstrate an obvious increase of the membrane fouling rate (13.7, 23.5 and 23.3 kPa d−1) on day 1 of cleaning, followed by a rapid reduction (6.4, −0.2 and 3.5 kPa d−1) on day 2 of cleaning. This indicates the rapid self-recovery ability of the NaClO-shocked sludge. Furthermore, as the operating time increased, the sludge extracellular polymeric substance (EPS) content initially increased, followed by a subsequent decrease, with the gradual improvement of sludge filterability that consequently reduced membrane fouling. Thermodynamic analysis revealed that the shocked-sludge surface properties, including the surface electron donor component (γ), hydrophobicity, adhesive energy and self-cohesive ability, were gradually restored to the raw sludge level, which reduced the membrane fouling potential.

Graphical abstract: Effects of NaClO shock on MBR performance under continuous operating conditions

Article information

Article type
Paper
Submitted
15 אוג 2020
Accepted
17 נוב 2020
First published
17 נוב 2020

Environ. Sci.: Water Res. Technol., 2021,7, 396-404

Effects of NaClO shock on MBR performance under continuous operating conditions

M. Sun, B. Hou, S. Wang, Q. Zhao, L. Zhang, L. Song and H. Zhang, Environ. Sci.: Water Res. Technol., 2021, 7, 396 DOI: 10.1039/D0EW00760A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements