From Polluted to Pure: How a New Nanocomposite is Transforming Water Treatment

February 23, 2024

Access to clean and drinkable water is vital for maintaining a healthy lifestyle. Yet, the surge in industrial and urban development has escalated the influx of pollutants into water bodies, marking a dire threat to human health. Notably, the paint and textile industries stand out for discharging dangerous substances, such as toxic metals and dyes, into our environment.

In response to this environmental challenge, Professor Dr Wong Ling Shing from the Faculty of Health and Life Sciences at INTI International University spearheaded a study with an international team from Vietnam, India, Malaysia, and Korea. Their research focused on developing a “Chitosan (CS) functionalised bismuth oxychloride/zinc oxide (BiOCl/ZnO) nanocomposite for enhanced photocatalytic degradation of Congo red (CR),” aiming at combating water pollution effectively.

Professor Dr Wong Ling Shing from INTI International University and a group of researchers found that the CS-BiOCl/ZnO nanocomposite quickly and effectively removes dyes from water, offering a reusable and efficient solution for dye-contaminated water.

Prof Wong highlighted the gravity of the situation by stating, “The contaminated waters are teeming with a range of toxic metals and harmful dyes, essential in producing paint and textile dye colourants, alongside aromatic complexes.”

Using azo dyes such as Congo red and Methylene blue is prevalent in the textile, paint, and printing sectors, significantly exacerbating water pollution. These dyes, known for their toxicity, stability, and resistance to degradation, pose severe risks to the environment and human health, including the potential for bladder cancer and genetic mutations.

Numerous techniques have been developed to tackle water pollution, such as adsorption, incineration, coagulation, ozonation, filtration, photocatalysis, and biological treatment. The research team’s innovation is the development of a functionalised BiOCl/ZnO nanocomposite that can effectively neutralise Congo red dye, a commonly used proxy for water pollutants. Their study found that this nanocomposite could break down the dye molecules.

The newly synthesised nanocomposite has demonstrated its effectiveness by degrading Congo red (CR) under UV light with an impressive 93% degradation rate within 40 minutes of exposure. Further tests have confirmed its sustained photocatalytic activity over three consecutive cycles, making it a potential reusable solution for purifying water contaminated with dye.

Prof Wong concluded, “The CS-BiOCl/ZnO nanocomposite has proven to be highly efficient, capable of removing a considerable amount of dye in a brief period while maintaining its effectiveness over multiple uses. This discovery holds great promise as a viable solution for purifying water tainted with dyes.”