Effects of temperature on nitrifying membrane-aerated biofilms: An experimental and modeling study.

Temperature is known to have an important effect on the morphology and removal fluxes of conventional, co-diffusional biofilms. However, much less is known about the effects of temperature on membrane-aerated biofilm reactors (MABRs). Experiments and modeling were used to determine the effects of temperature on the removal fluxes, biofilm thickness and morphology, and biofilm microbial community structure of nitrifying MABRs.

Unique stratification of biofilm density in heterotrophic membrane-aerated biofilms: An experimental and modeling study.

We consistently find a band of high cell density develop within heterotrophic membrane-aerated biofilms. This study reports and attempts to explain this unique behavior. Biofilm density affects volumetric reaction rates, biofilm growth rates, substrate diffusion, and mechanical behavior.

Effect of membrane type on the behavior of nitrifying membrane aerated biofilms: silicone membranes vs. micromembrane cords.

There is increasing interest in membrane-aerated biofilm reactors (MABRs), due to their energy efficiency and ability to intensify wastewater treatment. While MABR membranes play a key role, supporting biofilms and transferring O, little research has addressed how membrane types impact MABR performance. This research compared two types of membranes used in commercial MABRs: a silicone hollow-fibre membrane and a 'micromembrane cord,' consisting of an inert cord surrounded by fine proprietary polymeric membranes.

Assessing Intermediate Formation and Electron Competition during Thiosulfate-Driven Denitrification: An Experimental and Modeling Study.

There is increasing interest in thiosulfate-driven denitrification for low C/N wastewater treatment, but the denitrification performance varies with the thiosulfate oxidation pathways. Models have been developed to predict the products of denitrification, but few consider thiosulfate reduction to elemental sulfur (S), an undesirable reaction that can intensify electron competition with denitrifying enzymes. In this study, the model using indirect coupling of electrons (ICE) was developed to predict S formation and electron competition during thiosulfate-driven denitrification.

Unique biofilm structure and mass transfer mechanisms in the foam aerated biofilm reactor (FABR).

The foam-aerated biofilm reactor (FABR) is a novel biofilm process that can simultaneously remove carbon and nitrogen from wastewater. A porous polyurethane foam sheet forms an interface between wastewater and aerated water, making it a counter-diffusional biofilm process similar to the membrane-aerated biofilm reactor (MABR). However, it is not clear how biofilm develops the foam interior, and how this impacts mass transfer and performance.

Unraveling encapsulated growth of Nitrosomonas europaea in alginate: An experimental and modeling study.

Encapsulation is a promising technology to retain and protect autotrophs for biological nitrogen removal. One-dimensional biofilm models have been used to describe encapsulated systems; they do not, however, incorporate chemical sorption to the encapsulant nor do they adequately describe cell growth and distribution within the encapsulant. In this research we developed a new model to describe encapsulated growth and activity of Nitrosomonas europaea, incorporating ammonium sorption to the alginate encapsulant.

A computational model for the catalytic hydrogel membrane reactor.

The catalytic hydrogel membrane reactor (CHMR) is a promising new technology for hydrogenation of aqueous contaminants in drinking water. It offers numerous benefits over conventional three-phase reactors, including immobilization of nano-catalysts, high reactivity, and control over the hydrogen (H) supply concentration. In this study, a computational model of the CHMR was developed using AQUASIM and calibrated with 32 experimental datasets for a nitrite (NO)-reducing CHMR using palladium (Pd) nano-catalysts (~4.

New insight into CO-mediated denitrification process in H-based membrane biofilm reactor: An experimental and modeling study.

The H-based membrane biofilm reactor (H-MBfR) is an emerging technology for removal of nitrate (NO) in water supplies. In this research, a lab-scale H-MBfR equipped with a separated CO providing system and a microsensor measuring unit was developed for NO removal from synthetic groundwater. Experimental results show that efficient NO reduction with a flux of 1.

Catalytic Hydrogel Membrane Reactor for Treatment of Aqueous Contaminants.

Heterogeneous hydrogenation catalysis is a promising approach for treating oxidized contaminants in drinking water, but scale-up has been limited by the challenge of immobilization of the catalyst while maintaining efficient mass transport and reaction kinetics. We describe a new process that addresses this issue: the catalytic hydrogel membrane (CHM) reactor. The CHM consists of a gas-permeable hollow-fiber membrane coated with an alginate-based hydrogel containing catalyst nanoparticles.