New method helps to detect harmful industrial wastewater

Researchers at the University of Applied Sciences Northwestern Switzerland have developed a method for detecting harmful industrial wastewater. It helps companies to treat wastewater in a cost-effective and environmentally friendly way.

As a result, the wastewater can be safely discharged into the public sewage system, the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) announced on its website on Tuesday. Many chemical substances get into the wastewater from industrial operations, the effects of which on the environment are almost impossible to assess.

Companies pre-treat their wastewater using various technologies to ensure that the total amount of dissolved organic carbon does not exceed the legal limit. However, this value is not related to the toxic potential of the wastewater, said Miriam Langer, Professor of Ecotoxicology at the FHNW, in the press release.

Effect of the substances becomes visible

The method developed by the FHNW helps to visualize the effect of all substances contained in industrial wastewater. In a first step, microorganisms from sewage sludge break down organic substances in wastewater. This degradation test delivers the results faster than the established standard test. In just seven days instead of 28.

The effect of industrial wastewater on a group of particularly sensitive bacteria, the nitrifiers, was also assessed. These break down ammonium in biological wastewater treatment plants. The activity of nitrifiers shows whether wastewater interferes with the natural degradation process.

The final test, the bioassay, then shows whether the substances remaining in the wastewater are toxic to living organisms, the FHNW wrote. Their influence on the growth of unicellular algae, the swimming ability of water fleas and the natural luminosity of bioluminescent bacteria is tested.

SDA