Ozone Technical Glossary

A treatment approach that generates highly reactive species (often hydroxyl radicals) to oxidise difficult contaminants.

Why it matters: Ozone can be used alone or as part of AOP (e.g., ozone + UV or peroxide) depending on target compounds.

A rapid hygiene test that measures adenosine triphosphate (ATP) as an indicator of biological residue on surfaces.

Why it matters: Useful for validating cleaning effectiveness; it does not directly measure ozone dose.

An instrument that measures ozone concentration in air (typically in ppm) for safety monitoring in plant rooms and enclosed spaces.

Why it matters: Ozone is a respiratory irritant; ambient monitoring supports alarms, interlocks and safe operation.

Ozone can oxidise certain arsenic species, but “removal” typically requires downstream separation (e.g., adsorption/filtration) as part of a treatment train.

Why it matters: Avoid assuming ozone alone removes arsenic; design around oxidation + separation and verify performance with testing.

EU/UK regulatory framework for biocidal products. In practice, it affects how certain disinfection claims and biocide products are marketed and used.

Why it matters: Compliance messaging and documentation can be important for procurement, audits and public claims.

A halogen disinfectant commonly used in pools/spas; it behaves differently from chlorine in terms of residual and by-products.

Why it matters: In water applications, “ozone vs bromine” usually comes down to residual strategy and regulatory/site preferences.

Media used in catalytic ozone destructors to accelerate ozone conversion back to oxygen.

Why it matters: Catalyst choice impacts destructor size, temperature limits and maintenance intervals.

Formation and collapse of microbubbles due to pressure changes, sometimes used to enhance mixing and oxidation processes.

Why it matters: Can influence mass transfer and equipment wear; design must consider pump and injector conditions.

A widely used disinfectant that provides a measurable residual in distribution systems, commonly as free chlorine or combined chlorine (chloramines).

Why it matters: Ozone is strong but short-lived; many systems use ozone for primary treatment and chlorine for downstream residual (application dependent).

A vessel or hydraulic loop that provides the required contact time (CT) for ozone to react with water and achieve the target outcome.

Why it matters: Generator output alone does not guarantee performance; CT and mass transfer often set the real limit.

The most common ozone generation method, where a high-voltage field splits oxygen molecules to form ozone.

Why it matters: Performance and reliability depend on feed gas quality (dryness), cooling and electrical design.

A practical metric used to describe disinfection exposure, calculated as dissolved ozone concentration multiplied by contact time.

Why it matters: CT relates more directly to microbial inactivation than generator g/h ratings.

A measure of oxidisable material in water, commonly used as a wastewater strength indicator.

Why it matters: High COD can increase ozone demand and reduce residual/CT unless dosing and contact are designed correctly.

A process step where undissolved gas is separated from water, often used to control off-gas and improve downstream safety.

Why it matters: Off-gas management is essential where ozone could accumulate in enclosed or occupied areas.

The concentration of ozone dissolved in water (often mg/L). It can be measured online or via sampling methods.

Why it matters: DO₃ is the parameter most closely tied to CT and treatment performance.

The temperature at which moisture condenses from a gas. Lower dew point means drier gas.

Why it matters: Dry feed gas improves ozone stability and reduces corrosion risk in air-fed systems.

Dose is ozone applied; demand is ozone consumed by reactions with organics/inorganics and losses.

Why it matters: Meeting a target residual requires dosing above demand and verifying with measurement.

A component used to reduce moisture in the feed gas to protect the ozone cell and improve stability (e.g., refrigerant or desiccant dryers).

Why it matters: Moisture increases nitric acid risk (air-fed) and can reduce ozone output and cell life.

A gas distribution device (often porous) that introduces ozone as fine bubbles into a contact tank or loop.

Why it matters: Can be suitable when venturi hydraulics are not available, but tank design and off-gas control become critical.

Ozone generated directly from water via electrolysis, producing ozone in water (and sometimes gas) without a separate oxygen feed system.

Why it matters: Useful where compact “ozone-in-water” is needed, but capacity and cost differ from corona systems.

The gas supplied to the ozone generator: dry air or oxygen (from PSA, bottled oxygen, or LOX).

Why it matters: Oxygen-fed systems typically achieve higher concentration and better mass transfer, often improving efficiency.

A common rating for ozone generator production capacity, describing mass output over time.

Why it matters: g/h alone does not define performance; concentration, dissolution efficiency, CT and losses matter.

The time required for dissolved ozone concentration to drop by half. It varies with temperature, pH, organics, and catalysts.

Why it matters: Short half-life can require higher dosing or tighter control to maintain a residual.

Describes equilibrium partitioning of ozone between gas and liquid phases.

Why it matters: Helps explain why concentration, pressure and temperature affect dissolution behaviour and off-gas.

A safety or process condition that enables/disables ozone generation (e.g., ventilation proof, door switch, leak alarm, flow permissive).

Why it matters: Interlocks reduce operational risk and are often expected in industrial sites.

A high-purity oxygen supply option used for higher-capacity ozone systems and stable performance.

Why it matters: Often chosen when PSA capacity is insufficient or when consistent high concentration is required.

The process of moving ozone from the gas phase into water. It depends on concentration, injector design, pressure and mixing.

Why it matters: Many “underperforming ozone systems” fail on mass transfer, not generator nameplate output.

A concentration unit used for dissolved ozone in water. For dilute aqueous solutions, mg/L is approximately equivalent to ppm.

Why it matters: Useful for comparing targets, sensor readings and CT calculations.

Very small gas bubbles (typically sub-micron to micron scale) that can remain suspended for longer periods than conventional bubbles.

Why it matters: May improve gas transfer behaviour in some systems, but performance depends on water chemistry and application.

A gas volume referenced to standard conditions (temperature/pressure) to allow consistent comparison of gas flows and concentrations.

Why it matters: Ozone concentration (g/Nm³) uses this reference to avoid confusion across sites and conditions.

Undissolved ozone-containing gas leaving a contactor, tank or degassing vessel.

Why it matters: Off-gas must be safely routed and often destroyed to prevent ozone accumulation in occupied spaces.

A device that converts ozone back to oxygen, commonly using thermal or catalytic media.

Why it matters: Essential for safe off-gas management and to meet site safety expectations.

The amount of ozone per unit volume of gas, often expressed as g/Nm³ or weight percent.

Why it matters: Higher concentration can improve mass transfer and reduce gas flow requirements (duty dependent).

Water containing dissolved ozone. It is used for disinfection, oxidation and hygiene applications where a short-lived oxidant is advantageous.

Why it matters: Strong oxidising action with minimal persistent residue, but requires correct safety and verification.

An electrochemical measurement (mV) reflecting overall oxidising conditions in water, influenced by multiple species.

Why it matters: ORP is useful for trending, but it is not a direct measurement of dissolved ozone concentration.

A technology that produces oxygen on-site from air, commonly ~90–95% purity depending on design and flow.

Why it matters: Enables self-sufficient oxygen-fed ozone systems without bottled oxygen logistics.

A unit expressing concentration. In water, ppm is often approximately equal to mg/L for dilute solutions.

Why it matters: Used for ambient ozone limits and dissolved ozone targets; always confirm whether it refers to air or water.

The loss of pressure across piping, injectors, static mixers or contactors due to friction and flow restrictions.

Why it matters: Pressure drop drives venturi performance and pump selection, and can limit achievable mass transfer.

The measurable dissolved ozone remaining after contact/reaction, often targeted to confirm dosing or hygiene conditions.

Why it matters: Residual is application-specific; too high can create off-gas risk, too low may indicate insufficient CT.

Control strategy using ORP/redox signal to adjust ozone dosing, typically as a proxy rather than a direct ozone measurement.

Why it matters: Useful for trend control, but DO₃ measurement is better when precise ozone residual is required.

An inline mixing element used to improve gas–liquid contact and homogenise dissolved ozone concentration.

Why it matters: Can improve mass transfer and stabilise sensor readings downstream.

A pre-assembled, pipework-and-instrumented package that integrates multiple components into a single installation-ready unit.

Why it matters: Reduces site work, speeds commissioning and improves repeatability of installation.

A measure of water clarity caused by suspended particles, typically reported in NTU.

Why it matters: High turbidity can increase ozone demand and affect disinfection performance and sensor stability.

A measure of how much UV light passes through water. It often correlates with organic content and treatment difficulty.

Why it matters: While UVT is mainly discussed for UV systems, it’s a useful proxy for organics that can consume ozone.

An injector that uses pressure differential to draw ozone gas into a water stream and promote dissolution.

Why it matters: Effective when hydraulics allow it; backpressure and flow set the achievable suction and transfer.