The textile and batik industries are among the major contributors to water pollution worldwide. The wastewater they produce contains synthetic dyes that are not only difficult to degrade but also potentially harmful to the environment and human health. One commonly used dye is bromocresol green (BCG), which is known for its stability and resistance to removal from wastewater. This issue calls for solutions that are not only effective but also economical and sustainable. One increasingly developed approach is the utilization of industrial waste as raw material for treating other waste, in line with the principles of the circular economy that are actively being applied in various programs today.

Recent studies have shown that industrial waste such as spent bleaching earth (SBE), a byproduct of palm oil refining, and glycerin pitch, a byproduct of the biodiesel industry, can be converted into adsorbent materials. Through carbonization and chemical activation processes, glycerin pitch can be transformed into activated carbon. Even more interestingly, modification using phosphoric acid produces activated carbon with exceptionally high performance. This modified activated carbon has a highly porous structure with a surface area of approximately 859 m²/g. This structure allows more dye molecules to be adsorbed onto the material’s surface. For comparison, conventional activated carbon has a dye removal efficiency of about 72%, unmodified SBE removes around 82%, titanium-modified activated carbon achieves about 92%, while phosphorus-modified activated carbon can reach up to 99.56%. This means that nearly all dye molecules are successfully removed from the solution.

The removal process occurs through adsorption, where dye molecules adhere to the surface of the material through chemical interactions. One of the main advantages of phosphorus-modified activated carbon is its reusability. After use, the material can be regenerated through heating and still maintain high performance for up to six cycles. This is highly beneficial from both economic and sustainability perspectives, as it reduces the need for producing new materials.

This material has not only been tested in laboratory settings but also applied to real batik wastewater. The results are very promising, with a color removal efficiency of around 97.6%. Although a small amount of color remains, this is expected because real industrial wastewater contains a more complex mixture of chemical substances compared to model solutions used in laboratories. These findings demonstrate that industrial waste can be repurposed into high-value materials. Waste-based activated carbon shows great potential as a solution for water treatment. Through simple chemical modification, its performance can be significantly enhanced. In the future, this technology can be further developed for large-scale textile wastewater treatment, removal of various other pollutants, and sustainable waste-based water treatment systems.

Author: Alfa Akustia Widati, published in the Journal of Dispersion Science and Technology: https://www.tandfonline.com/doi/full/10.1080/01932691.2026.2643283

This article is a repost from the Popular Scientific Articles page of Universitas Airlangga (UNAIR) and has been adapted for publication on the Chemistry UNAIR website.
Original source: “Activated Carbon from Industrial Waste for Dye Pollution Remediation (UNAIR)”