Treating Natural Organic Matter (NOM) in Wastewater

A substantial increase in the concentration of Natural Organic Matter (NOM) in fresh waters, and also subsequently municipal wastewater effluents, has been reported worldwide in recent years. Likewise, micro-algae, flavours, odours, pesticides, endocrine disruptors and other emerging micropollutants are also on the rise.

Far more difficult to extract than other particulates, micropollutants like NOM are a challenge to reduce for most water treatment technologies. Like hard Chemical Oxygen Demand (COD), they are resistant to chemical and biological treatment systems. However, with the highly effective Actiflo® Carb from Veolia, wastewater treatment plants can ensure the production of high quality water through the reduction of all such compounds.

What is Natural Organic Matter (NOM)?

NOM is made up of a variety of organic substances, generated as a result of a number of biological, geological and hydrological cycles in aquatic ecosystems. As such, NOM can vary extensively with regards to its concentration and composition and this makes it difficult to reduce from a water supply.

Similarly, emerging micro-pollutants like endocrine disruptors, which predominantly come from everyday personal hygiene products that find their way into our water systems, are hard to filter efficiently via the use of conventional coagulation techniques. As micropollutants like these are on the rise, it is important that water treatment facilities have methods in place to facilitate their treatment prior to discharge to the watercourse.

Powdered Activated Carbon: An Effective Treatment Solution

Thankfully, there is one technique that has been shown to reduce micropollutants effectively, and that is the use of Powdered Activated Carbon (PAC). The absorbent properties of PAC offer an effective solution for the elimination of non-flocculable NOM, COD, micro-algae, flavours, odours, pesticides, endocrine disruptors and other emerging micropollutants in the water.

At Veolia, our Actiflo® Carb combines the performance of our rapid, high-performance Actiflo® solution with the absorption capacity of PAC. Combined, these methods achieve up to 95% reduction of pesticides and organic substances.

Featuring the same coagulation, flocculation and lamella settlement stages as the Actiflo®, the Actiflo® Carb has an additional upstream PAC contact tank to absorb the pollutants before they pass through the subsequent stages. The ballasted flocs are then settled from the treated water and pumped through hydrocyclones to separate the sludge from the Actisand and PAC, which can then both be recirculated back into the system for re-use.

The Actiflo® Carb is a compact, flexible solution, ideal for drinking and process water applications with a restricted footprint. It is also well-suited for use as an advanced tertiary treatment for wastewater. Due to the recirculation of the PAC, the system is also cost-effective, with minimal PAC usage compared to conventional inline dosing.

Depending on the quality of water to be treated, the Actiflo® Twin Carb is also available. This configuration consists of a unique dual-stage treatment in series – an Actiflo® clarification stage followed by the Actiflo® Carb. This is the ideal solution for influent water with a high solids concentration.

Both the Actiflo® Carb and Twin Carb systems are currently in use to tackle high pollutant content in the UK, Europe, Asia and the USA.


Chat with one of our experts about the Actiflo® Carb and Twin Carb here.