Published: 15. Apr 2022

Sulfinizer - sustainably solving problems with hydrogen sulphide

Sulfinizer Skaller

Water utilities in Denmark are struggling with rising problems of hydrogen sulphide in the sewers. To solve these problems, Aarhus Vand has partnered up with Envidan and made a sustainable filter that uses mussel shells to break down the hydrogen sulphide without chemicals.

Hydrogen sulphide is a toxic, foul-smelling and corrosive gas. When it is formed in the sewers, it releases a smell of rotten eggs, which bothers both the citizens and visitors near the wastewater facility. Also, hydrogen sulphide corrodes the concrete in the sewers, which decreases their durability.

This problem has arised because the utilities have become better at keeping their sewers tight. Because of the increasing rainfall and the climate changes, water utilities are starting to separate rainwater and wastewater in new pipes. This means that the rainwater is no longer diluting the wastewater, which then increases the concentration in the wastewater and creates a lower flow in the sewers.

Last, the utilities have sewered large areas of the land adn centralized the sewering by closing down small wastewater facilities. This means the water travels longer in the pipes, which gives the wastewater a longer time to develop hydrogen sulphide.

A solution based solely on nature products

Most places, the problem is solved by adding chemicals to the wastewater, but this is not a good idea for either the environment or the working environment. Therefore, the environmental company EnviDan partnered up with Aarhus Vand to develop a sustainable solution to get rid of the hydrogen sulphide problems. The established the company Sulfinizer, in cooperation with PBJ Miljø, and made an environmentally friendly solution, that both removes the smell and counteracts the corrosion in the sewers.

The solution is based on the positive effect that calcium has on hydrogen sulphide. The wastewater is ventilated through a filter made by mussel shells, whcih then converts the hydrogen sulphide into poorly soluble and unproblematic plaster. The shells are a biological waste product from the food industry and consists primarily of calcium. As a bonus, this filter also helps minimize the problems with other smelly gasses in the wastewater through other biological processes.

The win for us is solving a problem through this cooperation and creating a company that can help the entire sector. This way, we get new wins in the form of new innovation.
- Karsten Lumbye Jensen, CIO at Aarhus Vand

Testing gives hope for the future

The filter has been tested at Viby wastewater facililty in Aarhus, where the effect has been so good that Aarhus Vand has also installed it at the facilities in Maarslet and Tranbjerg. The utility has achieved a higher operational security, fewer obnoxious smells and a better duration economy. The filter is also an investment in a better water environment as the use of chemicals can be avoided. Both EnviDan and AarhusVand sees a huge business potential in distributing the filter to the entire water sector through the company, Sulfinizer.

It is an amazing product, we have developed with Aarhus Vand and PBJ Miljø - efficient, simpel and based on the nature's own materials. We have already experienced a great interest in the concept, not just in Denmark, but also in Sweden and Norway, and I am sure that this product also has potential further than the Scandinavian market.
- Morten Fjerbæk, CEO at EnviDan