A GAK filter is an essential component of modern water treatment systems and is used to remove organic and inorganic pollutants and micropollutants from water. Granular activated carbon, the heart of this filter, is characterized by an extremely high specific surface area and a microporous structure that enables effective adsorption of pollutants.
Table of contents
Production of granular activated carbon (GAK)
The production of granular activated carbon involves several steps that are specifically aimed at creating the unique porous structure:
Selection of raw materials: Organic materials such as coal, coconut shells or wood are usually used.
Pyrolysis: The material is carbonized at high temperatures (400-800°C) in the absence of oxygen to remove volatile components and create a basic structure.
Activation: The carbonized mass is treated chemically (e.g. with phosphoric acid) or physically (with steam or CO₂ at temperatures of 800-1000°C). This step creates the dense network of micro- and mesopores that is responsible for adsorption.
Technical background
Adsorption mechanism
Adsorption in a GAC filter takes place through physical and chemical interactions. Pollutants such as organic molecules, chlorine compounds or heavy metal ions bind to the pore structure of the activated carbon. This significantly improves the water quality by permanently removing impurities.
Structure of a GAK filter
A typical GAK filter consists of:
- Filter container: Contains the activated carbon bed.
- Inlet and outlet systems: Control the water flow and ensure even distribution of the water.
- Backwash systems: Prevent the filter from becoming clogged with solids by periodically cleaning the carbon.
Photo: Our GAK filters in GRP tanks for medium and small water flows(ALMA FIL AK)
Regeneration
The adsorption capacity of activated carbon is limited. Once saturated, the activated carbon must either be replaced or thermally regenerated. Thermal regeneration removes the adsorbed substances and restores the original function of the activated carbon.
Applications
Drinking water treatment
- Removal of pesticides, herbicides and drug residues.
- Improvement of taste and odor.
Industrial wastewater treatment
- Treatment of wastewater in the chemical and pharmaceutical industries.
- Removal of poorly degradable organic compounds and pollutants such as AOX.
Recycling of process water
- Recirculation and reuse of process water in production plants, e.g. in the food or beverage industry.
Special industrial applications
- Removal of phenols, BTEX (benzene, toluene, ethylbenzene and xylenes) or chlorine compounds from industrial wastewater.
Advantages
- High adsorption capacity: Efficient removal of a wide range of pollutants.
- Adaptability: Versatile use for different types of water and waste water.
- Regenerability: Activated carbon can be thermally regenerated several times.
Photo: Granulated activated carbon
Challenges
- Cost-intensive regeneration: Requires specialized regeneration plants.
- Increased operating costs: Due to regular maintenance and replacement of the activated carbon.
- Technical monitoring: To ensure the optimum function of the filter system.
GAK filters in the context of ALMAWATECH
ALMAWATECH offers customized GAK filter systemsthat are tailored to specific industrial requirements. Our systems are characterized by sophisticated control technology, automated backwash systems and integrated monitoring. In addition, we carry out pilot tests with customer-specific water samples to ensure optimum filter configuration and efficiency.
Conclusion
GAK filters are indispensable tools in modern water and wastewater treatment. They enable sustainable and efficient removal of pollutants and contribute to compliance with strict environmental regulations. With customized solutions and innovative technology, ALMAWATECH ensures that GAC filters deliver maximum performance in every application.
For further information on our products, please feel free to contact us at any time!
