Insights on fouling development and characteristics during different fouling stages between a novel vibrating MBR and an air-sparging MBR for domestic wastewater treatment

Chuansheng Wang; Tze Chiang Albert Ng; Meiyue Ding; How Yong Ng

doi:10.1016/j.watres.2022.118098

Insights on fouling development and characteristics during different fouling stages between a novel vibrating MBR and an air-sparging MBR for domestic wastewater treatment

Water Res. 2022 Apr 1:212:118098. doi: 10.1016/j.watres.2022.118098. Epub 2022 Jan 18.

Authors

Chuansheng Wang¹, Tze Chiang Albert Ng², Meiyue Ding³, How Yong Ng⁴

Affiliations

¹ Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 3, 117580 Singapore.
² Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 3, 117580 Singapore; National University of Singapore Environmental Research Institute, 5A Engineering Drive 1, 117411 Singapore. Electronic address: albert.n@nus.edu.sg.
³ Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 3, 117580 Singapore; National University of Singapore Environmental Research Institute, 5A Engineering Drive 1, 117411 Singapore.
⁴ Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 3, 117580 Singapore; National University of Singapore Environmental Research Institute, 5A Engineering Drive 1, 117411 Singapore. Electronic address: howyongng@nus.edu.sg.

PMID: 35114533
DOI: 10.1016/j.watres.2022.118098

Abstract

Membrane fouling remains a major hindrance to a prevalent application of membrane bioreactor (MBR) for wastewater treatment. Vibrating membrane technology has recently attracted increasing attention in energy-efficient fouling control in MBR compared to air sparging. However, little is known about its fundamental fouling control mechanism and whether the vibrating MBR (VMBR) is a highly effective strategy to control fouling constitutions and fouling sources compared to the conventional air-sparging MBR (ASMBR). This study operated two parallel MBRs with vibrating or air-sparging membrane modules for long-term (215 d) real domestic wastewater treatment. Effects of air sparging and vibration rates on fouling control, fouling development and fouling sources across three fouling stages were comprehensively evaluated. Results showed that the VMBR achieved 70% lower fouling rates compared to the ASMBR due to a remarkable retardation in each fouling stage by membrane vibration. The VMBR significantly reduced over 62.7% of colloid_CL and SMP_CL within the cake layer (CL) to simultaneously alleviate the reversible and irreversible fouling compared to the ASMBR. The comparatively lower dissolved organic matter (DOM) and biopolymer contents in the cake layer of the VMBR resulted in a slower TMP rise. The main DOMs in the foulants of both MBRs were found in the following order: aromatic protein > soluble microbial by-products > other organics. EPS_ML from mixed liquor (ML) contributed more DOMs to form membrane foulant than the SMP_ML in both MBRs. Aromatic proteins and soluble microbial products in the EPS_ML were markedly reduced in the VMBR but increased in the ASMBR in high-shear phase, demonstrating higher effectiveness in fouling control by membrane vibration. This study provided insights into understanding fouling control, fouling development characteristics and fouling mechanisms between the VMBR and ASMBR, which might guide the researchers and engineers to apply novel vibrating MBRs to better control membrane fouling for holistic wastewater treatment in full scale.

Keywords: Dissolved organic matters; Domestic wastewater; Fouling control; Fouling development; Vibrating membrane bioreactor.

MeSH terms

Air
Bioreactors
Membranes, Artificial*
Wastewater
Water Purification*

Substances

Membranes, Artificial
Waste Water