SUSU Scientists Have Proposed A Flow Reactor For Purifying Water From Textile Dyes

Oleg Bolshakov, Elena Korina, and Vladislav Fadeev, staff members of the Nanotechnology Research Center at SUSU, together with colleagues from Serbia, developed and tested a flow-through electrochemical reactor for purifying water from Reactive Black 5, a dye used in fabric dyeing.

These dyes adhere well to fibers, making them suitable for industrial applications. However, once released into wastewater, this same property becomes a problem: the dye persists in the environment for a long time, discolors the water, blocks light penetration, and can harm aquatic organisms.

Filters, sorbents, ozone, membrane technologies, and other approaches are already used for water purification. However, many methods have limitations: they require consumables, require complex maintenance, require high energy costs, or require subsequent disposal of contaminated waste.

SUSU scientists and their international colleagues have proposed a different approach: purifying water using electric current. Contaminated water passes through a reactor, and active particles form on the surface of a special electrode, which destroy the dye molecules.

"The main difference of this development is its flow-through format. The water isn't simply contained in a laboratory tank, but moves through the reactor. This brings the system closer to real-world industrial wastewater treatment conditions," explained Vladislav Fadeev, a young scientist at SUSU.

To operate the reactor, the researchers used a multilayer electrode. One of its working layers was additionally modified with holmium, a rare earth element. This modification helped improve purification efficiency and maintain the electrode's activity during reuse.

In laboratory tests, the Reactive Black 5 dye solution completely lost its color within 90 minutes. After 15 repeated cleaning cycles, the system's effectiveness remained virtually unchanged.

This development could be useful for creating compact units that will purify water from persistent organic pollutants. The next step is testing on real wastewater and further optimization of the reactor design.

The results of the study were published in the Korean Journal of Chemical Engineering, published by Springer Nature.