Characteristics of a Self-Forming Dynamic Membrane Coupled with a Bioreactor in Application of Anammox Processes

Abstract

A novel anammox self-forming dynamic membrane bioreactor (SFDMBR) was proposed to achieve an efficient anammox process with high biomass retention and cost-effective operation. The cake layer formed on nylon mesh (pore size, 20−25 μm) was referred to as a dynamic membrane (DM). The high permeability of the DM layer contributed to low transmembrane pressure (TMP), which kept below 10 kPa for 50 days in one filtration cycle of 82 days. Compared to the high TMP (mainly > 20 kPa) in the MBR using polyvinylidene fluoride (PVDF) microfiltration membrane, energy can be significantly conserved in the SFDMBR. Besides, the mature DM layer achieved efficient biomass retention comparable to that of PVDF membrane, which favored anammox bacteria enrichment. Concomitantly, an appropriate microenvironment for autotrophic anammox bacterial growth with wellcontrolled extracellular polymeric substances (EPS) concentration (33.22 mg•g −1 VSS) was achieved in SFDMBR. According to specific filtration resistance (SFR) analysis, reducing the EPS concentration in the bulk sludge improves sludge filterability and alleviate fouling, which was achieved in the SFDMBR system with a low SFR of 1.47 × 10 12 m −1 •kg −1 . Our results show that the cost-effective operations and technical merits make anammox SFDMBRs promising for practical applications.

Development of a Flow-through Biofilm Reactor for Anammox Startup and Operation: Nitrogen Removal and Metacommunity

“…In addition, it is also reasonable to hypothesize that different living environments induced by flux variations (Figure S1) might create and alter the distributions of the attached biofilm community, thus resulting in a different reactivity toward nitrogen conversion. In future applications, the selection of suitable flux should take many factors into consideration, such as the changes of hydraulic resistance, energy cost, as well as turbidity and nitrogen removal performance …”

Membrane processes

“…When the A-MBR system was bubbling with 10% CO 2 , nitrogen removal capacity increased from 2.6 ± 0.4 g m −3 d to 3.6 ± 0.4 g m −3 d. Moreover, membrane fouling was reduced in the A-MBR system with CO 2 addition, possibly because of overcoming mineral precipitation on the membrane due to lower pH. Zhu, Cao, Cao, and Wang (2019) conducted a study on anammox self-forming dynamic MBR (SFD MBR) using nylon mesh. The cake formed on the mesh is called dynamic membrane showed high permeability, high biomass retention, and a low transmembrane pressure (TMP).…”

“…Zhu, Cao, Cao, and Wang (2019) conducted a study on anammox self‐forming dynamic MBR (SFD MBR) using nylon mesh. The cake formed on the mesh is called dynamic membrane showed high permeability, high biomass retention, and a low transmembrane pressure (TMP).…”

Innovative Biofouling Control for Membrane Bioreactors in Cold Regions by Inducing Environmental Adaptation in Quorum-Quenching Bacteria

“…The polysaccharide and protein concentrations were measured as EPS concentrations using the phenol-sulfuric acid method and the Bradford assay, respectively. Despite the fact that some previous studies have questioned their accuracy, , the methods are still valid for comparing EPS concentrations if the difference of compared data is significant, as widely adopted in MBR studies. − …”