Activated Carbon Filters: Reliable Adsorption Technology in Industrial Water Treatment

Activated carbon filters are particularly effective at removing: • Free chlorine and chloramine • Volatile organic compounds (VOCs) such as phenols, benzene and toluene • Pesticides and agricultural chemical residues • Compounds that cause taste and odour • Dissolved organic matter that causes colour (especially in textile effluents) • By-products such as trihalomethanes (THMs) However, they cannot remove dissolved inorganic ions (e.g. sodium, nitrate, hardness). Ion exchange or reverse osmosis systems are required for these substances.

On an industrial scale, activated carbon filters are widely used for: • Chlorine removal ahead of reverse osmosis • Dye and colour removal in the textile industry • Taste/odour correction in the food and beverage industry • Filtration of organic pollutants in pharmaceutical and chemical plants • Protecting public health in drinking water production plants • VOC removal in petrochemical plants These filters not only improve process quality but also help protect advanced treatment units (such as RO membranes).

The life of the carbon media depends on the flow rate, pollution level, carbon type and operating conditions. In general: • Replacement every 8–18 months is recommended in industrial applications. • When used for chlorine removal, performance decreases once the dechlorination capacity is exhausted. • The return of colour, taste, odour and dissolved organic matter indicates carbon saturation. For tighter control, continuous measurement of inlet and outlet parameters and monitoring of differential pressure are recommended.

Backwashing removes suspended solids (sludge, particles, etc.) that accumulate on the carbon bed. This process: • Prevents filter clogging • Increases filtration efficiency • Reduces pressure loss • Extends media life Automatic backwash systems can be programmed by time or differential pressure. This is especially critical in high-flow industrial systems.

The carbon type directly affects filtration performance. Commonly used carbon types: • Coconut shell carbon: thanks to its high micropore ratio, ideal for chlorine and low-molecular-weight organics. • Wood-based carbon: its lignin structure gives it wider pores; used for colour and odour removal. • Coal-based carbon: suitable for industrial wastewater and heavy pollutants. At aquaDESTECH, our engineers select the carbon type based on the application and water analysis.

An efficient and safe activated carbon system includes the following components: • Pre-filtration (sand filter, cartridge filter) • Automatic backwash valves • pH and ORP sensors • PLC control panel • Flow meter and pressure gauge • Bypass line • Outlet water quality monitoring sensors Thanks to these components, the system runs stably and delivers maximum safety with minimal operator intervention.

For a standard reverse osmosis system, once the site survey and design are complete: • Manufacturing time: 3–5 weeks • On-site installation and commissioning: 3–7 days In total, the system is operational within 1–2 months. Delivery time may vary depending on capacity.

Activated carbon filters are usually positioned upstream of RO systems. In this way they: • Protect RO membranes from oxidative chlorine damage • Reduce membrane fouling by lowering the organic load in the water • Extend the overall operating life of the system Using these two systems together brings major economic and environmental advantages in water treatment.

The maintenance procedure is quite simple: • Weekly: check inlet/outlet differential pressure • Monthly: observe the backwash cycle and measure flow • Every 3–6 months: analyse inlet and outlet parameters (especially chlorine, TOC, colour) • Yearly: assess the condition of the carbon media and replace if necessary In aquaDESTECH systems, automatic monitoring and alarm functions keep operator intervention to a minimum.