Occurrence and removal of microbial indicators from municipal wastewaters by nine different MBR systems.

Nine different membrane bioreactor (MBR) systems with different process configurations (submerged and external), membrane geometries (hollow-fiber, flat-sheet, and tubular), membrane materials (polyethersulfone (PES), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE)) and membrane nominal pore sizes (0.03-0.2 μm) were evaluated to assess the impact of influent microbial concentration, membrane pore size and membrane material and geometries on removal of microbial indicators by MBR technology.

Peak flux performance and microbial removal by selected membrane bioreactor systems.

A pilot study was conducted over a period of 18 months at the Point Loma Wastewater Treatment Plant (PLWWTP) in San Diego, CA to evaluate the operational and water quality performance of six selected membrane bioreactor (MBR) systems at average and peak flux operation. Each of these systems was operated at peak flux for 4 h a day for six consecutive days to assess peak flux performance. Virus seeding studies were also conducted during peak flux operation to assess the capability of these systems to reject MS-2 coliphage.

Kinetics of nitrate and perchlorate reduction in ion-exchange brine using the membrane biofilm reactor (MBfR).

Several sources of bacterial inocula were tested for their ability to reduce nitrate and perchlorate in synthetic ion-exchange spent brine (30-45 g/L) using a hydrogen-based membrane biofilm reactor (MBfR). Nitrate and perchlorate removal fluxes reached as high as 5.4 g Nm(-2)d(-1) and 5.

Effect of membrane configuration on bench-scale MF and UF fouling experiments.

Hollow fiber and flat sheet membranes were compared in side-by-side bench-scale experiments to evaluate whether the configuration has an impact on the rate of membrane fouling. Both microfiltration (MF) and ultrafiltration (UF) membranes were evaluated. In general, flat sheet membranes fouled more rapidly than hollow fiber membranes.

Effect of coagulation on the size of MF and UF membrane foulants.

Microfiltration (MF) and ultrafiltration (UF) have become common water treatment technologies for the removal of particles from natural waters. Many water utilities are now integrating MF/UF with other treatment processes to provide treatment for nonparticulate contaminants. Research is needed to understand the impact that other processes have on MF/UF performance.

Investigation of seawater reverse osmosis fouling and its relationship to pretreatment type.

Desalination of seawater using reverse osmosis (RO) technology is an important option available to water-scarce coastal regions. A major challenge to seawater reverse osmosis (SWRO) is membrane productivity decline due to fouling. Systematic studies in the area of SWRO fouling are lacking as compared to RO fouling by freshwater.