GLOSSARY

Activated Sludge: A biological wastewater treatment process in which air is bubbled through the wastewater, stimulating the growth of microorganisms that consume organic pollutants.

Anaerobic Digestion: A biological process occurring in the absence of oxygen where microorganisms break down organic matter, producing biogas (primarily methane and carbon dioxide).

Aerobic: A process that requires the presence of oxygen.

Anoxic: A process that occurs in the absence of dissolved oxygen but with the presence of combined oxygen (e.g., in nitrates).

Bioreactor: A vessel used for biological processes, such as the degradation of organic matter by microorganisms.

Biomass: The total mass of microorganisms in a biological treatment process.

BOD (Biochemical Oxygen Demand): A measure of the amount of oxygen required by microorganisms to decompose organic matter in a water sample.

CAS (Conventional Activated Sludge): A traditional biological wastewater treatment process that uses a settlement tank (clarifier) for solid/liquid separation after the aeration tank.

COD (Chemical Oxygen Demand): A measure of the amount of oxygen required to chemically oxidize the organic matter in a water sample.

Flux: The rate at which permeate (treated water) passes through a membrane per unit area.

Fouling (Membrane Fouling): The accumulation of material on the membrane surface or within the membrane pores, which reduces flux and increases transmembrane pressure.

HRT (Hydraulic Retention Time): The average time that wastewater remains in a bioreactor.

Immersed MBR: An MBR configuration where the membrane modules are submerged directly in the bioreactor tank.

MABR (Membrane Aerated Biofilm Reactor): An aerobic biological treatment process where a biofilm is fixed to a membrane surface, with oxygen supplied through the membrane.

MBR (Membrane Bioreactor): A wastewater treatment process that integrates membrane separation with a biological activated sludge process.

Mixed Liquor: The mixture of activated sludge and wastewater in the aeration tank of a biological treatment process.

OPEX (Operational Expenses): The ongoing costs associated with operating a system, such as energy, labor, and maintenance.

Permeability: A measure of how easily a fluid can pass through a membrane.

Permeate: The treated water that has passed through the membrane.

Polishing: A final treatment step to improve the quality of treated wastewater.

Primary Sludge: Sludge removed from the primary sedimentation tank in conventional wastewater treatment.

Sidestream MBR: An MBR configuration where mixed liquor is pumped from the bioreactor to an external membrane unit for separation.

Sludge: The solid or semi-solid residue generated during wastewater treatment.

Sludge Conditioning: Pre-treatment of sludge to improve its dewaterability.

Sludge Dewatering: Reducing the moisture content of sludge by mechanical means.

Sludge Stabilization: Processes that reduce the odor, putrescence, and pathogen levels in sludge.

Sludge Thickening: Reducing the volume of sludge by removing water, resulting in a pumpable product.

SRT (Solids Retention Time): The average time that the biological solids (biomass) remain in a biological treatment system.

TMP (Transmembrane Pressure): The pressure difference across the membrane that drives the filtration process.

WAS (Waste Activated Sludge): The excess activated sludge that is removed from the biological treatment process.