Khalifa University researchers in the United Arab Emirates have developed a material inspired by mussels that can remove textile dyes from wastewater, which could potentially transform the wastewater treatment industry.

The team modified a polymer called polydopamine with an ionic liquid to create a new adsorbent material that is described as being highly selective and efficient at removing anionic pollutants from water.

“Surface and groundwater pollution caused by industrial dye-loaded wastewater effluents threatens human health and ecological systems, causing a serious environmental problem in many countries,” said chemical engineering professor Hassan Arafat.

He continued: “Several treatment techniques have been applied to remove dyes from wastewater, and among these, adsorption is considered the most economically feasible and easily applied. However, traditional adsorbents offer low selectivity, and the process can produce secondary waste products.”

The researchers turned to nature for inspiration and looked to mussels, marine animals that attach themselves to a variety of surfaces using byssus threads made from a protein containing dopamine. Polydopamine is a synthetic polymer that mimics the structure of this dopamine-containing protein, and it has the ability to coat a variety of surfaces and provides a versatile platform for surface modifications.

“As a material with many functional groups, extraordinary self-adhesive properties, and biocompatibility, the potential applications for polydopamine-based materials are abundant,” added professor Arafat. “However, its adsorption capacity is low compared to other conventional adsorbents.”

To increase the absorption rate, the scientists modified the material with an ionic liquid that can dissolve a wide range of compounds and be recycled for reuse.

Methanol was used to wash the material and desorb the dyes used in experimental testing. The team put the material through four cycles of adsorption-desorption without any significant performance deterioration or loss of structural integrity, and believe this proves its potential as an adsorbent material for use in industrial wastewater treatment applications

The team made up of chemical engineering professors Hassan Arafat and Enas Nashef, as well as researchers Rawan Abu Alwan, Botagoz Zhuman and Mahendra Kumar, published their findings in the Chemical Engineering Journal.