How to Remove Antibiotics from Water: Adsorption vs Light Breakdown

Jim Crocker
22nd April, 2025

How to Remove Antibiotics from Water: Adsorption vs Light Breakdown

Microscopic imaging (a–c) and elemental analysis (d–i) confirm the successful attachment of sulfamethoxazole to the silver phosphate (Ag3PO4) surface following both adsorption and photocatalytic degradation, providing physical evidence for the material's ability to remove the antibiotic from water.

Image adapted from: Elkomy et al. / CC BY (Source)

Key Findings

  • *Researchers in Egypt removed over 95% of the antibiotic SMX from water using silver phosphate.*
  • *Using light, the silver phosphate broke down nearly 98% of SMX, enhancing water quality.*
  • *The silver phosphate material can be reused multiple times, offering a sustainable water treatment solution.*
Sulfamethoxazole (SMX) is a widely used antibiotic essential for treating bacterial infections. However, its presence in surface waters and wastewater treatment plants poses significant risks to both human health and the environment. Residues of SMX can disrupt aquatic ecosystems and contribute to the development of antibiotic-resistant bacteria, making the removal of this pharmaceutical contaminant a critical environmental challenge. Researchers at Beni-Suef University, Egypt[1] have addressed this issue by exploring two advanced water treatment techniques: adsorption and photocatalytic degradation using silver phosphate (Ag₃PO₄). Their study aims to effectively remove SMX from contaminated water, enhancing water quality and reducing the potential adverse effects of antibiotic residues. Adsorption is a process where contaminants are trapped on the surface of a material, known as an adsorbent. In this study, Ag₃PO₄ was utilized for its high adsorption capacity. The researchers conducted experiments to determine the optimal conditions for maximum SMX removal, including the solution's pH, the amount of adsorbent used, the initial concentration of SMX, and the contact time required to reach equilibrium. Under the best conditions, adsorption achieved a 95.15% elimination of SMX, with a remarkably high maximum adsorption capacity (Qmax) of 1299.7 mg/g. This indicates that Ag₃PO₄ is highly effective at capturing SMX from water. Photocatalytic degradation is another promising technique where a catalyst, in this case, Ag₃PO₄, is activated by light to break down contaminants into harmless substances. The study found that photocatalytic degradation removed 98.2% of SMX under optimal conditions. This high efficiency is attributed to the ability of Ag₃PO₄ to generate reactive species when exposed to light, which then degrade SMX molecules into carbon dioxide and water, effectively mineralizing the pollutant. The methods used to characterize the materials involved several analytical techniques. Elemental dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were employed to understand the structural properties of Ag₃PO₄. Additionally, Brunauer–Emmett–Teller (BET) analysis and scanning electron microscopy (SEM) were used to examine the surface area and morphology of the adsorbent, ensuring its suitability for effective SMX removal. Recycling and reusability of the adsorbent and photocatalyst are crucial for practical applications. The study demonstrated that Ag₃PO₄ could be efficiently recycled as an adsorbent using distilled water for up to four cycles. For photocatalytic applications, a 0.1 M NaOH solution was the most effective for regenerating the catalyst, followed by water and ethanol solutions. This ability to reuse Ag₃PO₄ without significant loss of performance highlights its potential for sustainable water treatment solutions. Previous studies have also explored various materials and methods for removing antibiotics from water. For instance, cinnamon wood biochar (CWBC) was evaluated for its effectiveness in adsorbing sulfamethoxazole, showing significant reductions in plant uptake of the antibiotic[2]. Another study investigated biochar derived from activated sludge biomass, which demonstrated high adsorption capacities for SMX and lincomycin, another common antibiotic, highlighting the versatility of biochar materials in water purification[3]. Additionally, zeolite beta-templated carbon (BTC) and its nitrogen-doped form (nBTC) showed exceptional adsorption capacities for SMX, with nBTC achieving a maximum adsorption capacity of 1367 mg/g, surpassing many other adsorbents[4]. These studies collectively underscore the potential of carbon-based materials in addressing antibiotic contamination in water systems. The research from Beni-Suef University builds upon these findings by demonstrating that Ag₃PO₄ not only provides high adsorption and photocatalytic degradation efficiencies but also offers practical advantages in terms of recyclability and stability. The Fritz-Schlunder model was identified as the best fit to describe the adsorption process of SMX onto Ag₃PO₄, indicating a reliable and predictable removal mechanism. By integrating advanced materials like Ag₃PO₄ with proven adsorption and photocatalytic techniques, this study contributes to the development of effective strategies for mitigating antibiotic pollution in water. The high removal rates achieved, combined with the material's reusability, present a viable solution for enhancing water treatment processes and protecting environmental and public health from the adverse effects of pharmaceutical contaminants.

EnvironmentBiotechBiochem

References

Main Study

1) A comparison between adsorption and photocatalytic degradation for the management of sulfamethoxazole in water

Published 19th April, 2025

https://doi.org/10.1038/s41598-025-95947-2

Related Studies

2) Retention of sulfamethoxazole by cinnamon wood biochar and its efficacy of reducing bioavailability and plant uptake in soil.

https://doi.org/10.1016/j.chemosphere.2022.134073

3) Adsorption of sulfamethoxazole and lincomycin from single and binary aqueous systems using acid-modified biochar from activated sludge biomass.

https://doi.org/10.1016/j.jenvman.2024.120742

4) Aqueous adsorption of sulfamethoxazole on an N-doped zeolite beta-templated carbon.

https://doi.org/10.1016/j.jcis.2020.08.065


Related Articles

An unhandled error has occurred. Reload 🗙