Dyes are an important part of many industries. They are used in dyeing clothes or printing labels. However, the use of dyes can also have negative effects on the environment and our health. Therefore, the removal of dyes is an important part of industrial wastewater treatment.
How do dyes get into wastewater?
Dyes enter wastewater through various industrial sectors. One is the food and beverage industry, which processes natural products and thus adds natural dyes to its wastewater. In addition, the textile industry also works with dyes. When clothes are dyed and then washed, the dyes get into the water. But dyes also play a crucial role in plastic recycling. Labels or other plastic products are often printed. Before recycling, it is important to remove these dyes from the plastic – the so-called deinking.
Why is the removal of dyes from wastewater important?
The removal of dyes from wastewater is important for several reasons. Firstly, dyes can be toxic and have a negative effect on the environment. When they enter water bodies, they can promote the growth of algae and reduce the oxygen content of the water, which in turn can lead to the suffocation of fish and other aquatic life. In addition, some dyes are also harmful to health and cause disease.
Which processes are suitable for the efficient removal of dyes?
Over the last few years, PPU Umwelttechnik GmbH has developed one of the most efficient processes for the removal of dyes from wastewater – the ClearFox® DiOx EO. This is an oxidation process with diamond electrodes that convert the contaminants in the wastewater into the strongly oxidising OH radical. The DiOx EO module consists of an anode and a cathode surrounded by the discoloured wastewater. By adding electrical energy, the oxidation process begins.
In a recent laboratory experiment, the ClearFox® team tested the degradation of fluorescein. This is a bright yellow dye. Among other things, it is used in the food and beverage industry to colour drinks. It is also used in water analysis to examine currents. In the model test of the ClearFox® DiOx, around 22 V voltage and 1.5 A strength were applied. 3 ml of fluorescein was dissolved in 1.5 litres of water. Complete degradation of the dye was achieved after about 18 hours.
Conclusion
The removal of dyes is an important part of industrial wastewater treatment. Especially for the protection of water bodies and for the health of numerous living organisms, it is crucial to completely remove dyes from wastewater. With the ClearFox® DiOx EO, PPU Umwelttechnik GmbH has developed a process that reliably removes dyes from wastewater. This is already in use on an industrial scale and will make a decisive contribution to wastewater treatment in the future.
