Anaerobic Membrane Reactors

Abstract

In the last decade anaerobic membrane reactors (AnMBRs) have evolved from aerobic MBRs, with the membrane either external or submerged within the reactor. These reactors can achieve high chemical oxygen demand (COD) removals (∼98%) at low hydraulic retention times (HRTs) of 3 hours. In addition, since the membrane stops biomass being washed out of the reactor, they are capable of enhancing performance with inhibitory substrates, and at psychrophilic and thermophilic temperatures, and enable nitrogen removal via Anammox. As with MBRs, fouling is an issue, but addition of activated carbon or resins/precipitants can remove soluble organic products (SMPs) and enhance flux. Due to their low energy use and solids production, and a solids-free effluent, they also have considerable potential to enhance nutrient and water recycling. Nevertheless, more work is needed to compare fouling in aerobic and anaerobic systems, to determine how much knowledge in aerobic systems can be transferred, to determine how reactor operation influences fouling, to evaluate the effect of different additives to the reactor on membrane fouling, to determine whether nitrogen removal can be incorporated into AnMBRs, to determine methane solubility at low temperatures and recover it from the effluent, and to establish sound mass and energy balances on pilot scale plants to evaluate the economics of AnMBRs.

Tracking performance and disturbance in decentralized wastewater treatment systems with fluorescence spectroscopy

“…Although the compartmentalized configuration of ABRs makes them more resilient to shock loads, variable flow conditions, and other disturbance, 6 the treatment efficiency of anaerobic wastewater treatment systems, including ABRs, can be severely impacted by scum formation, 7 which may be monitored using fluorescence-based metrics. Disturbance from the buildup of fats, oils, and grease (FOG) in scum layers was recently shown to negatively impact performance of an ABR–anaerobic filter (AF) system treating domestic wastewater from a community of ∼80 homes in Durban, South Africa (Pietruschka, pers.…”

Influence of temperature and temperature shock on sludge properties, cake layer structure, and membrane fouling in a submerged anaerobic membrane bioreactor

“…Its potential for wastewater treatment lies on some of the principal advantages of SAnMBR systems, such as high quality effluent, complete solidliquid separation, high loading rate, low sludge production, renewable energy source production (i.e., CH 4 ) and small footprint [1,2]. Also, the SAnMBRs have low energy consumption compared to side-stream anaerobic membrane bioreactors.…”

Characterisation of soluble microbial products (SMPs) in anaerobic bioreactors

“…Also of contemporary importance is the role of SMP/EPS in membrane fouling of MBR technologies, which are becoming more prevalent globally nowadays (Roseenberger et al, 2006;Jarusutthirak and Amy, 2006;Meng et al, 2009;Wang and Waite, 2009;Jiang et al, 2010;Stuckey, 2010a). Membrane autopsies reveal significant fouling resistance is contributed by an uneven distribution of SMP/EPS (Cho and Fane, 2002), and this resistance is directly correlated with SMP/EPS, which undergo intermolecular or intramolecular ionic cross-linking, which subsequently clogs the membrane pores and leads to further fouling (Lin et al, 2014;Okamura et al, 2009).…”