GAC Fundamentals
Deep dive into adsorption science, carbon structure, surface chemistry, and the mechanisms of contaminant removal
Advanced adsorption systems for removing organic contaminants, VOCs, taste and odour compounds, chlorine, and micropollutants from water and wastewater
CFD, P&ID, SCADA and commissioning for critical water treatment plants.
Plant layouts, piping isometrics and construction-ready engineering drawings.
Flow, mixing and thermal CFD across treatment and process equipment.
Full mechanical, physico-chemical, biological and sludge equipment range.
The Science of Adsorption
Granular Activated Carbon (GAC) is the most widely used adsorption medium for critical water treatment processes, leveraging the extraordinary surface area of activated carbon to remove dissolved organic contaminants through physical adsorption and chemical reactions. A single gram of activated carbon can have a surface area exceeding 1,000 m², providing immense capacity for contaminant capture.
The Adsorption Process
GAC filtration operates through a combination of physical adsorption, chemisorption, and catalytic reactions to remove a wide range of contaminants from water.
Van der Waals forces attract organic molecules to the carbon surface, trapping them within the pore structure through physisorption.
Chemical bonds form between contaminants and surface functional groups, permanently removing reactive compounds like chlorine.
Carbon surface catalyses reactions such as chlorine conversion to chloride, providing simultaneous dechlorination.
Biological GAC (BAC) supports biofilm growth that biodegrades adsorbed organics, extending carbon service life.
Granular bed structure provides physical filtration of particulates down to 10-20 microns.
Comprehensive Adsorption Capabilities
Benzene, toluene, TCE, PCE, MTBE
Free chlorine, chloramines, chlorine dioxide
Geosmin, MIB, phenolic compounds
Atrazine, 2,4-D, glyphosate, lindane
Ibuprofen, antibiotics, hormones
PFOA, PFOS, GenX, short-chain PFAS
Selecting the Right Carbon for Your Application
The most common type for critical water treatment processes, offering excellent adsorption capacity and durability.
Premium carbon with highest hardness and micropore structure, ideal for critical applications.
Mesoporous structure ideal for larger molecules and decolorization applications.
Modified carbons with enhanced properties for specific contaminant removal.
Systems for Every Application Scale
Space-efficient pressure vessels engineered for small to medium flow applications. Ideal for point-of-entry systems, small industrial facilities, and polishing applications. Available in FRP or steel construction with manual or automatic backwash options.
Diameter range 200-600mm, vertical vessels with minimal footprint requirements
1-20 m³/h capacity with single or multi-vessel configurations
Manual, semi-automatic, or fully automatic backwash options
Versatile pressure filters for industrial and commercial applications. Steel or stainless steel vessels with comprehensive underdrain systems and advanced control options. Suitable for process water, wastewater polishing, and drinking water treatment.
Optimised bed depth (1.0-2.0m) and hydraulic loading for maximum adsorption
Large access manways, sample ports, and carbon sampling points
20-100 m³/h capacity with parallel vessel configurations available
Heavy-duty gravity and pressure filters for large-scale industrial and municipal applications. Custom-engineered systems with multiple cells, automated carbon transfer, and regeneration capabilities. Designed for continuous 24/7 operation.
Concrete or steel construction with corrosion-resistant linings
Designed for on-site or off-site thermal reactivation
100-1,000+ m³/h with multi-cell configurations
Engineering Parameters & Performance Data
| Parameter | DF GAC-C (Compact) | DF GAC-S (Standard) | DF GAC-I (Industrial) |
|---|---|---|---|
| Flow Rate Range | 1-20 m³/h | 20-100 m³/h | 100-1,000+ m³/h |
| Vessel Diameter | 200-600 mm | 600-2,000 mm | 2,000-5,000+ mm |
| Carbon Bed Depth | 0.6-1.0 m | 1.0-1.5 m | 1.5-3.0 m |
| Hydraulic Loading | 5-15 m/h | 10-20 m/h | 10-25 m/h |
| Empty Bed Contact Time | 5-15 minutes | 10-20 minutes | 15-30 minutes |
| Vessel Material | FRP / Steel | Steel / SS 316 | Steel / Concrete |
| Operating Pressure | 2-6 bar | 2-8 bar | Atmospheric - 6 bar |
| Backwash Rate | 20-30 m/h | 25-35 m/h | 25-40 m/h |
| Carbon Volume | 50-500 kg | 500-5,000 kg | 5,000-100,000+ kg |
Industries & Processes We Serve
Comprehensive Technical Resources
Explore detailed information about GAC technology, system design, operation, and optimisation through our comprehensive technical resources.
Deep dive into adsorption science, carbon structure, surface chemistry, and the mechanisms of contaminant removal
Sizing calculations, vessel selection, bed depth optimisation, hydraulic design, and configuration options
Thermal reactivation processes, on-site vs off-site options, cost analysis, and spent carbon management
Start-up procedures, backwash optimisation, breakthrough monitoring, carbon replacement, and troubleshooting
Detailed comparison of granular vs powdered activated carbon for different applications and cost scenarios
PFAS, pharmaceuticals, microplastics and other emerging contaminants - removal capabilities and system design
Engineering Excellence & Reliability
We source only high-quality activated carbon from certified manufacturers, with full traceability and performance documentation. Custom carbon selection for specific applications.
Decades of experience across diverse industries ensure optimal system design, carbon selection, and operating parameters for your specific contaminants.
From initial testing and pilot studies through design, installation, commissioning, and ongoing support - Reynolds & Bauhm provides end-to-end GAC solutions.
Regeneration services, spent carbon management, and sustainable sourcing options to minimise environmental impact and lifecycle costs.
Automated backwash, effluent monitoring, and predictive maintenance systems to optimise performance and minimise operator intervention.
Documentation, testing protocols, and regulatory expertise to ensure your GAC system meets all applicable discharge and product quality standards.
Complete Treatment Solutions
Pre-treatment filtration to protect GAC beds from particulate fouling and extend carbon service life.
Explore Multimedia FilterAutomated pre-filtration systems for continuous protection of downstream GAC vessels.
Self-Cleaning FiltersPost-GAC disinfection systems to ensure microbiological safety of treated water.
Water AerationComplete range of filtration technologies for pre-treatment and polishing applications.
View Filtration SystemsContainerised adsorption: GAC lead-lag, ion exchange, PFAS removal.
View Containerised OptionDiscuss your specific requirements with our technical team and receive a tailored proposal for your project.
Contact UsContact our engineering team to discuss your contaminant removal requirements and receive a customised GAC system design with optimal carbon selection.
For the depth-filtration step in this process we use multimedia filters with graded anthracite/sand/garnet beds. The technical detail behind sizing, media specification, backwash hydraulics and field troubleshooting lives in a dedicated library — pick the topic:
Product page with design parameters and process-train context.
ViewSizing, freeboard, distributors, nozzle-plate underdrain.
ViewAnthracite, sand, garnet specifications — ES, UC, SG.
ViewAir scour, fluidisation hydraulics, valve sequencing.
ViewWhere MMF fits in pretreatment, polishing, reuse trains.
ViewMudballs, channelling, breakthrough, media loss diagnoses.
ViewOur expertise spans multiple industries with sector-specific water treatment solutions.