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Tertiary Treatment

Final polishing, filtration, and disinfection that transforms biologically treated effluent into compliant discharge. Advanced oxidation, membrane separation, and activated carbon adsorption for the most stringent permit requirements.

The Final Barrier Before Discharge

Ensuring every effluent stream meets its permit requirements

Tertiary treatment provides the final polishing step that removes residual suspended solids, pathogens, colour, and specific contaminants remaining after secondary biological treatment. For applications with stringent discharge limits, water reuse requirements, or sensitive receiving waters, tertiary treatment is essential for consistent compliance. Reynolds & Bauhm designs each tertiary stage to complement upstream processes and achieve the required effluent quality reliably.

Filtration

Sand, multimedia, and membrane filtration remove residual suspended solids and polish turbidity to levels required for sensitive receiving waters or reuse applications.

Disinfection

UV, ozone, and chemical disinfection destroy pathogenic organisms to meet microbial discharge limits and protect public health in receiving environments.

Advanced Oxidation

Ozone, UV/H±0.2O±0.2, and Fenton processes destroy refractory organic compounds, pharmaceutical residues, and micropollutants that evade biological treatment.

Filtration Systems

Removing fine suspended solids and polishing turbidity

Pressure Sand Filters

Multi-media pressure filters with graded sand and anthracite layers for depth filtration of biologically treated effluent. Backwash systems with air scour and water wash ensure sustained performance over long operating cycles.

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Self-Cleaning Filters

Automatic backwash filters that clean themselves without interrupting flow. Ideal for continuous operation applications where downtime is not acceptable and operator intervention must be minimised.

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Cartridge Filters

Absolute-rated cartridge filters for final polishing where specific particle size removal is required. Disposable element design with housings in stainless steel or reinforced thermoplastic for chemical compatibility.

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Disc Filters

Cloth media disc filters for tertiary solids removal achieving very low TSS in a compact footprint. Low headloss and automated backwash make them ideal for retrofit and upgrade applications.

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Membrane Filtration

Ultrafiltration and microfiltration membranes providing absolute barrier filtration for suspended solids, bacteria, and colloidal matter. Produces consistent filtrate quality for reuse or discharge to sensitive waters.

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Activated Carbon

Granular activated carbon adsorption for colour, odour, organic micropollutant, and pharmaceutical residue removal. Rechargeable carbon systems with steam regeneration or disposable carbon changeouts.

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Disinfection Technologies

Destroying pathogens to protect receiving waters

UV Disinfection

Ultraviolet irradiation destroys bacteria, viruses, and protozoan cysts by disrupting their DNA. No chemical residuals are introduced to the effluent, making UV ideal for discharge to sensitive aquatic ecosystems and for water reuse applications. Reynolds & Bauhm UV systems include automatic quartz sleeve cleaning, UV intensity monitoring, and validated dose delivery.

Medium-pressure and low-pressure lamp options
Automatic sleeve wiping for sustained transmittance
Validated UV dose for target organism inactivation
No chemical residual in treated effluent
Compact footprint with open-channel or closed-vessel design
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Ozone Disinfection

Ozone is one of the most powerful oxidants available for wastewater disinfection. It destroys a broad spectrum of pathogens including chlorine-resistant organisms, removes colour and odour, and oxidises organic micropollutants. On-site ozone generation eliminates chemical storage and transport risks.

Corona discharge ozone generation on-site
Effective against chlorine-resistant pathogens
Decolourisation and deodorisation in one step
No harmful chemical residuals in effluent
Degrades to oxygen - environmentally benign
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Advanced Oxidation Processes

Destroying refractory contaminants and micropollutants

UV/H±0.2O±0.2 AOP

Combined ultraviolet irradiation and hydrogen peroxide dosing generates hydroxyl radicals that destroy pharmaceutical residues, endocrine disruptors, and persistent organic compounds resistant to biological treatment.

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Ozone AOP

Ozone-based advanced oxidation with hydrogen peroxide or UV enhancement achieves rapid oxidation of colour, COD, and specific contaminants in textile, pharmaceutical, and chemical effluents.

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Fenton Process

Iron-catalysed hydrogen peroxide oxidation for high-COD industrial effluents. Effective at low pH for colour removal, COD reduction, and degradation of complex organic structures in textile and dyehouse wastewater.

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Wet Air Oxidation

High-temperature, high-pressure oxidation for concentrated industrial effluents with very high COD. Destroys refractory organics that resist conventional biological and chemical treatment at ambient conditions.

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Process Fundamentals & Design

This treatment stage is engineered to achieve specific contaminant removal targets while providing stable, predictable performance across variable inlet conditions. Design parameters are calculated from wastewater characterisation data, regulatory requirements, and site-specific constraints including footprint, energy availability, and operator capability.

Process Optimisation

Design validated by CFD modelling and pilot testing to confirm performance guarantees.

Mechanical Reliability

Equipment selected for 20-year design life with minimal wearing parts and easy access.

Chemical Efficiency

Automated dosing and feedback control minimise reagent consumption and sludge production.

Compliance Assurance

Online monitoring and data logging demonstrate continuous consent compliance.

Design Parameters

Design Flow10 – 5,000 m³/h (application specific)
Inlet VariabilityDesigned for 1:3 peak-to-average flow ratio
Removal Efficiency85 – 99% depending on target contaminant
Hydraulic RetentionCalculated from kinetic constants and safety factors
Power Consumption0.5 – 5.0 kWh/100 m³ (process dependent)
Chemical DoseAuto-controlled based on online analysers
Sludge Production0.2 – 1.5 kg DS/kg contaminant removed
MaterialsSS304, SS316L, or carbon steel with coating

Integration with Treatment Train

No treatment stage operates in isolation. This process is designed to receive conditioned influent from upstream stages and deliver effluent quality suitable for downstream processes. Hydraulic and organic loading rates are balanced across the complete treatment train to prevent bottlenecking and ensure overall plant efficiency. Our engineers model the complete flowsheet to optimise Capital expenditure and Operating expenditure across the plant lifecycle.

Upstream Protection

Screening, equalisation, and pre-treatment protect this stage from damage and overload.

Downstream Conditioning

Effluent quality ensures downstream biology, filtration, or disinfection performs optimally.

Recycle Streams

Reject streams, filtrate, and centrate are routed back to appropriate upstream points.

Related Pages & Equipment

Equipment Catalogue

Browse our full range of water treatment equipment and systems.

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DAF Systems

Dissolved air flotation for solids and oil separation.

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Lamella Clarifiers

High-rate settling for primary and secondary clarification.

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Biological Treatment

Activated sludge, MBBR, and SBR systems for organic removal.

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Sludge Dewatering

Belt press, centrifuge, and screw press dewatering.

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Chemical Dosing

Automated coagulant, flocculant, and pH correction systems.

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Pilot Testing

Validate process performance with on-site pilot trials.

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Speak to Our Engineers

Request a consultation or quotation for your project.

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Design Your Tertiary Polishing Stage

Our process engineers will determine the optimal combination of filtration, disinfection, and advanced oxidation to meet your discharge permit or water reuse requirements.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.