The textile and batik industries are among the major contributors to water pollution worldwide. The wastewater generated 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 demands 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 streams, in line with the circular economy principle that is actively implemented in various programs today.
Recent research has shown that industrial waste such as spent bleaching earth (SBE)—a waste product from the palm oil refining process—and glycerin pitch as a byproduct of the biodiesel industry can be utilized as adsorbent materials.
Through carbonization and chemical activation processes, glycerin pitch can be converted into activated carbon. More interestingly, modification with phosphoric acid produces activated carbon with exceptionally high performance.
This modified activated carbon possesses a highly porous structure with a surface area reaching approximately 859 m²/g. This structure enables more dye molecules to be adsorbed onto the material’s surface.
For comparison, conventional activated carbon demonstrates dye adsorption efficiency of 72%, unmodified SBE adsorbs approximately 82% of dye compounds, titanium-modified activated carbon achieves 92%, while phosphorus-modified activated carbon reaches up to 99.56%. This means that nearly all dye compounds are successfully removed from the solution.
The adsorption process occurs through the attachment of dye molecules onto the material surface via chemical interactions.
One of the major advantages of phosphorus-modified activated carbon is its reusability. After use, the material can be regenerated through heating while maintaining high performance for up to six usage cycles.
This aspect is particularly important from economic and sustainability perspectives because it reduces the need for producing new materials.
The material was not only tested under laboratory conditions but was also applied to actual batik wastewater. The results were highly promising, with color removal efficiency reaching approximately 97.6%.
Although slight residual coloration remained, this is expected because real industrial wastewater contains mixtures of various chemical compounds that are more complex than laboratory model solutions.
The findings of this study demonstrate that industrial waste can be repurposed into high-value materials.
Waste-based activated carbon holds significant potential as a solution for water treatment. Through simple chemical modification, activated carbon performance can be substantially improved.
In the future, this technology may be developed for industrial-scale textile wastewater treatment, removal of various other pollutants, and sustainable waste-based water treatment systems.
Author: Alfa Akustia Widati, published in Journal of Dispersion Science and Technology: https://www.tandfonline.com/doi/full/10.1080/01932691.2026.2643283
This article is reposted from the Popular Scientific Article page of Universitas Airlangga (UNAIR) and has been adapted for publication on the Chemistry UNAIR website.
Original source: “Activated Carbon from Industrial Waste to Address Dye Pollution (UNAIR)”
