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Wastewater Tertiary Polishing
Water & Effluent Treatment

Wastewater Tertiary Polishing

Tertiary polishing of biologically treated wastewater using granular activated carbon to remove micropollutants, dissolved organic carbon, and trace contaminants before discharge or reuse.

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The Challenge
Conventional wastewater treatment (primary plus secondary biological) removes biological oxygen demand and suspended solids but leaves dissolved organic micropollutants that survive the biological stage. Surface water discharge consents increasingly target these residuals; reuse for irrigation or industrial water requires further polishing.
Quick Answer

Wastewater tertiary polishing applies granular activated carbon downstream of biological treatment to remove the micropollutants that survive the secondary stage: pharmaceutical residue, pesticide breakdown products, persistent organic compounds, and disinfection byproduct precursors. Outlet meets surface water discharge or reuse specification.

Wastewater Tertiary Polishing

Biological Treatment Leaves Persistent Residuals

Conventional wastewater treatment (primary settling plus activated sludge biological treatment) removes biological oxygen demand, ammonia, and suspended solids to the level that the secondary clarifier achieves. What survives are the dissolved organic micropollutants, pharmaceutical residue, pesticide breakdown products, persistent organic pollutants, and the THM precursors that haunt downstream drinking water reuse. These residuals are the focus of the modern tertiary polishing stage.

GAC as the Tertiary Adsorption Stage

The SorbiTech tertiary stage uses GAC 1240 in a downflow fixed bed contactor. The bed is sized by empty bed contact time matched to the target micropollutant class: 15 to 25 minutes for general polishing, longer for the more recalcitrant compounds. Outlet meets the surface water discharge consent or the reuse specification.

Wastewater Tertiary Polishing process equipment

Reuse vs Discharge Configuration

Where the polished effluent is discharged to a surface water body, the wetted materials and the polishing duty meet the regional surface water consent. Where the polished effluent is reused for irrigation, industrial process water, or indirect potable reuse, the wetted materials shift to NSF/ANSI 61 certification and the carbon grade shifts to the food contact compliant grade.

Service Contract and Reactivation

The SorbiTech GAC is reactivated thermally through the SorbiTech reactivation programme, which lowers the lifecycle cost by 40 to 60 percent versus single use. Sector coverage is industrial water and municipal water treatment.

Selection Guidance

GAC 1240 in a downflow fixed bed contactor sized for the target contaminant (EBCT 15 to 25 minutes for general micropollutant polishing). Backwash and reactivation cycle. NSF/ANSI 61 wetted materials if effluent is reused as drinking water.

How SorbiTech Solves It

A Specified, Verified Solution

Define the duty

We capture your process conditions: flow, composition, pressure, temperature, and the target outlet specification.

Select media & configuration

Our engineers recommend the adsorbent grade and system type that meet the duty with margin.

Size & engineer

Bed sizing, vessel design, and cycle parameters are engineered to your case and documented for approval.

Commission & verify

We support loading, start up, and performance verification against the guarantee.

Recommended Products & Systems

Media

Adsorbents & Media

  1. 01 Activated Carbon GAC 1240 Adsorbent Activated Carbon GAC 1240 Coal based granular activated carbon for dechlorination, taste and odour, and dissolved organics in water. Form 12 × 40 US mesh (0.42–1.70 mm)
  2. 02 Powdered Activated Carbon Adsorbent Powdered Activated Carbon Fine powder carbon for slurry dosing in water treatment, sugar decolorization, pharmaceutical purification, and emergency contamination response. Form 200×325 mesh (45–75 µm)
  3. 03 SorbiTech Activated Alumina Aa 201 Fluoride Removal Defluoridation Adsorbent Activated Alumina AA-201 Smooth sphere activated alumina for compressed air and gas drying, fluoride removal, and guard bed duty. Water Cap. ≥ 18 %
Equipment

Engineered Systems

  1. 01 SorbiTech Activated Carbon Water Contactor Drinking Water GAC Polishing Contactor Equipment Activated Carbon Water Contactor Granular activated carbon fixed bed water contactor for dechlorination, taste and odour, dissolved organic carbon, and emerging contaminant polishing in drinking water and process… Capacity 5–2,000 m³/h
  2. 02 SorbiTech Community Defluoridation Treatment Unit Activated Alumina Fluoride Removal Skid Equipment Community Defluoridation Treatment Unit Containerised activated alumina defluoridation unit for community and decentralised drinking water supply to the WHO guideline of 1.5 mg per litre. Capacity 0.5–50 m³/h
  3. 03 SorbiTech Multi Media Filter Water Treatment Pressure Vessel Mmf Equipment Multi Media Filter Multi media filter for suspended solids and turbidity removal upstream of activated carbon polishing, reverse osmosis, or process reuse in water treatment trains. Capacity 5–500 m³/h
  4. 04 SorbiTech Coalescing Filtration Skid Oil Water Coalescer Filter Package Equipment Coalescing Filtration Skid Two stage coalescer and separator skid that removes fine dispersed hydrocarbons and solids from water down to single digit ppm. It is the polishing… Capacity 2–200 m³/h
Industries

Industries Using This Application

  1. 01 SorbiTech Industrial Water Treatment Pulp Paper Mill Water Block Daf GAC Sector Industrial Water Treatment Process water polishing, cooling tower blowdown, boiler feedwater, and groundwater remediation served by SorbiTech adsorbent media and engineered treatment skids.
  2. 02 SorbiTech Municipal Water Treatment WWTP Clarifiers GAC Contactor Hall Sector Municipal Water Treatment Activated carbon and activated alumina for taste and odour, dechlorination, and fluoride removal in drinking water treatment. NSF eligible media and complete treatment units.

Specify a Solution for This Application

Provide your process conditions and our team will recommend the grade, configuration, and sizing.

contact@sorbitech.com