Avoid foam and foul odours

The wastewater gas H2S creates obnoxious smells for neighbours and can pose an occupational hazard, while foam formation can cause processing problems. Norlex Chemicals has the products and the expertise to fight both.

“The presence of foam in effluent from wastewater treatment plants can prompt complaints from local people and authorities, even if the foam is harmless to humans and the environment. Likewise, obnoxious smells, e.g. from foul-smelling hydrogen sulphide (H2S), can cause more dissatisfaction among neighbours.”


For most applications, light foam is not problematic, but excessive foam and/or dense foam can often lead to different processing problems. These problems range from incorrect readings from control and measuring equipment (such as thermometers and level and mass flow transmitters) to poor mixing of reactants in chemical process tanks and products that get stuck in the foam and cause losses in production.

Defoamers are used to limit, reduce, avoid or eliminate foaming. Norlex Chemicals offers defoamers to treat process water and wastewater in applications that include:


Defoaming in digesters (silicone-free)


Defoaming during sludge dewatering (decanting, and more)


Defoaming during the handling of slurry and separation of digested slurry


Industrial applications where foam is a problem


Membrane-compatible defoamers for use in MBR systems and more

Hydrogen sulphide control

Hydrogen sulphide (H2S) is a colourless, highly toxic, flammable and corrosive gas that smells like rotten eggs. Due to anaerobic conditions in pressurerised pipelines, sulphate in waste water is reduced to sulphide or hydrogen sulphide, which causes foul odour, corrosion and potentially hazardous working conditions. This can be avoided by adding special chemicals to combat H2S.

There are two different types of products for combating H2S. One type prevents the formation of the gas by adding nitrate. The bacteria will then convert the nitrate rather than the sulphate so that H2S is not formed. This requires that there is always an excess of nitrate. However, this type of product will not break down gas that has already been formed. The other type works by breaking down H2S and simultaneously prevents the formation of the gas. This type of product can thus also be used in applications where H2S is formed and must be eliminated.
Pumping stations can also be equipped with active carbon filters. The carbon that is used in these filters has the affinity to adsorb H2S. Thereby, the gas does not escape and create obnoxious smells in the surrounding neighbourhood.

Norlex Chemicals has all types of products to control H2S, including dual-action products that both prevent the formation of H2S and eliminate the presence of H2S.

Keep in mind that foul odours may also be due to the formation of other foul-smelling gases besides H2S. Norlex Chemicals can help solve odour problems in all types of applications.


An agreement with Norlex amounts to much more than the supply of quality products. We provide service throughout the process in the form of support, knowledge and troubleshooting, so the customer gets a cost-effective solution. Call +45 4594 0994 or send an email to info@norlex.com.

Please send sales inquiries to sales@norlex.com.