Researchers Use Light To Remove Toxic Dyes From Waste Water.

Researchers at Texas Tech University point out that during the use of visible light (visible light), they found a new way to remove toxic dye pollutants from waste water. "Tech" Visible light refers to the part of the human eye that can be seen (felt) in electromagnetic spectrum.

When cloth dyeing is performed, one of the final stages of treatment is washing process, which helps to fix colors and remove excess dyes on cloth. However, it is estimated that this process may produce up to 200 thousand tons of waste water containing residual synthetic dyes and pigments annually.

In view of the fact that traditional wastewater treatment processes are inefficient and unenvironmentally friendly, and dyes are usually designed for light fastness, temperature and detergents, most dyes remain in the environment and are not easily decomposed. This method for cleaning toxic substances is the innovative technology currently needed.

In the past, the process of dye decomposition was mainly through the use of ultraviolet (UV). But now, in collaboration with researchers in the Department of chemical engineering and mechanical engineering, Texas Tech Department of Enviro, Dezhou Polytechnic University. Nmental Toxicology) Professor Seshadri Ramkumar and Ph.D. candidate Lihua Lou found a way to decompose dye, that is, filtering water through special nanofiber net and exposing it to visible light. This process is called photodegradation (photodegradation).

For this study, Lou added nanoparticles into polymer solutions and then spun into nanofibers via electrospinning. When synthetic nanoparticles / nanofibers are immersed in red dye water containing Luo Danming B (RhB), chemical reactions will occur.

Researchers found that 80% of Luo Danming B was degraded within 6 hours, and the remaining 20% slowly degraded, and disappeared completely in 49 days.

Ramkumar pointed out: "the research is mainly focused on the removal of toxic dyes because it is a persistent challenge for the textile industry".

Removing color compounds is one of the most difficult tasks for wastewater treatment plants, because dyes and pigments are not easily biodegradable. This is also one of the most important tasks. These dyes may pose a threat to the human ecosystem.

Lou explains: "some dyes cause highly permanent mutations and toxicity. Luo Danming B is a highly water-soluble compound and is widely used in coloring agents for textiles. However, wastewater containing rhodamine B may stimulate inflammation of skin and eyes and suction channels of humans and animals. In addition, there are also some health problems, such as neurotoxicity (neurotoxicity), carcinogenicity (carcinogenicity), reproductive toxicity (reproductive toxicity) and developmental toxicity (developmental toxicity), all of which are caused by Luo Danming B wastewater.

Based on these results, the results are very important. In addition to the successful removal of dyes from nanoparticles / nanofibers, the use of visible light to remove dyes can also achieve this, without excessive two pollution.

Ramkumar added: "our research covers many disciplines and has solved an important problem in the global textile industry. After the photodegradation process is completed, the synthetic materials in water can be easily removed without excessive harmful substances.