Fouling Development in A/O-MBR under Low Organic Loading Condition and Identification of Key Bacteria for Biofilm Formations

Abstract

Membrane fouling in membrane bioreactors (MBR) remains a major issue and knowledge of microbes associated with biofilm formation might facilitate the control of this phenomenon, Thus, an anoxic/oxic membrane bioreactor (A/O-MBR) was operated under an extremely low organic loading rate (0.002 kg-COD·m−3·day−1) to induce membrane fouling and the major biofilm-forming bacteria were identified. After operation under extremely low organic loading condition, the reactor showed accumulation of total nitrogen and phosphorus along with biofilm development on the membrane surface. Thus, membrane fouling induced by microbial cell lysis was considered to have occurred. Although no major changes were observed in the microbial community structure of the activated sludge in the MBR before and after membrane fouling, uncultured bacteria were specifically increased in the biofilm. Therefore, bacteria belonging to candidate phyla including TM6, OD1 and Gammaproteobacteria could be important biofilm-forming bacteria.

A novel nanofiltration based membrane bioreactor (NF-MBR) and reverse osmosis (RO) for water reclamation

“…It has been reported that bioflocculation could be beneficial to membrane fouling reduction in conventional MBRs ( Van den Broeck et al, 2012), its impact in NF-MBRs will be discussed in Section 5.3.3. (Takimoto et al, 2018, Jo et al, 2016, Xia et al, 2012. Also, the microbial communities in both NF-MBRs had comparable relative abundances (Figure 5-7) with similar observed OTU, Chao1, Shannon and Simpson diversity indexes (Table 5-5).…”

7-Aminocoumarin-4-acetic Acid as a Fluorescent Probe for Detecting Bacterial Dipeptidyl Peptidase Activities in Water-in-Oil Droplets and in Bulk

“…The 16 s rDNA library preparation, sequencing, and data analysis were carried out based on a previous report. 32 Sequencing methods are described in detail in the Supporting Information . Metagenomic sequencing data were analyzed with the Quantitative Insights Into Microbial Ecology software (version 1.9.1).…”

“…The 16 s rDNA library preparation, sequencing, and data analysis were carried out based on a previous report . Sequencing methods are described in detail in the Supporting Information.…”

Performance of modified hollow fiber membrane silver nanoparticles-zeolites Na–Y/PVDF composite used in membrane bioreactor for industrial wastewater treatment

“…Fouling occurs due to the accumulation of pollutants in wastewater and the formation of biofilms by activated sludge [ [11] , [12] , [13] ]. In recent years, many studies on the modification of membrane material by mixing zeolite into the membrane to increase the flux have been reported.…”