Tea Waste Biochar: A Green Solution for Antibiotic Pollution
Researchers have developed an innovative way to use S/N co-doping technology and hydrothermal methods to turn tea residue into a powerful adsorbent that can remove tetracycline from water. This sustainable approach offers both environmental and economic benefits.
Understanding the Antibiotic Pollution Crisis
Tetracycline (TC) is a widely used antibiotic in both human and livestock medicine. However, it frequently ends up in water sources, where it harms aquatic ecosystems and promotes antibiotic resistance. Since traditional wastewater treatment cannot fully eliminate TC, new and more effective methods are urgently needed.
Innovation: Tea Residue Biochar with S/N Co-Doping
A team from Beijing Technology and Business University transformed tea waste into sulphur and nitrogen co-doped biochar (SNBC) using hydrothermal carbonisation. This sustainable process not only repurposes agricultural waste but also enhances the structure of the biochar for better adsorption performance.
Key results:
- 94.16% TC removal at 25°C within 10 hours.
- 271.18 mg/g adsorption capacity, exceeding many conventional biochars.
- Works effectively at pH 4–9.
- Uses π-π interactions, hydrogen bonding, and pore filling to capture contaminants.
How S/N Co-Doping Improves Performance
Tea leaves naturally contain nitrogen. By adding sodium thiosulfate (Na₂S₂O₃·5H₂O) during preparation, sulfur atoms are introduced, boosting the biochar’s:
- Porosity and surface area.
- Functional groups for pollutant binding.
- Chemical stability for long-term use.
Performance Compared to Regular Biochar
When tested against unmodified biochar, SNBC showed:
- 2.5× higher surface area.
- Up to 9.38× greater TC adsorption.
- Stable monolayer adsorption behavior, confirming reliability.
Environmental and Practical Benefits
This approach solves two problems at once—reducing antibiotic pollution and recycling food industry waste. It supports circular economy principles and can be scaled for both rural and industrial water treatment.
Reference: https://doi.org/10.1016/j.jenvman.2024.121601
You can learn the basics in our guide: What is Biochar? A Complete Beginner’s Guide to Climate-Smart Soil Solutions.
