Scholarlink

Purpose <p>Anthropized environments are known to be widely contaminated by pharmaceuticals, particularly antibiotics, through the spreading and dumping of contaminated water or animal wastes. However, little is known about contamination of high-altitude environments, such as the Bolivian Altiplano. The objective of this study was to evaluate the retention of the antibiotic sulfamethoxazole (SMX) in the Bolivian altiplano by measuring SMX sorption in 10 soils collected throughout the Katari watershed.</p> Methods <p>Sulfonamides (SA) are of interest due to their significant use and mobility in natural environments. The sorption and retention mechanisms of the antibiotic SMX were determined by sorption assays in ten soils with varying physical-chemical properties, collected throughout the Katari watershed. The role of organic matter in SMX retention was studied in more detail by characterizing the types of Soil Organic Carbon (SOC) in different soils using Differential Scanning Calorimetry (DSC) to compare the ratios of labile and recalcitrant components in the organic carbon of the soils studied.</p> Results <p>SMX sorption followed linear isotherms in all soils (r²&gt;0.8), with sorption strength (Kd) varying greatly (0.16–16.0&#xa0;L.kg<sup>− 1</sup>) and correlating with organic carbon (OC) content (Log(K<sub>oc</sub>) = 2.4+/-1.5). OC-rich soils—particularly those with more labile and recalcitrant fractions— showed higher SMX sorption by hydrophobic/π−π interactions, hydrogen-bonding, and metal complexation. Results showed that SMX sorption decreased with pH increase due to changes in SMX speciation (neutral/anionic). Neutral SMX, dominant in acidic soils, binds more effectively, whereas SMX<sup>−</sup> is subject to repulsion from negatively-charged soil surfaces. High nitrogen content possibly altered SOC composition (soils 5–10) increasing SMX-binding sites. Calculated R-factors suggest the presence of two soil groups in the watershed, soils 5–10 being highly vulnerable to SMX compared to soils 1–4.</p> Conclusion <p>This study permitted to determine SMX sorption parameters in the Katari watershed, which were used to predict SMX reactive transfer in the Altiplano over a wide range of conditions. The results are in line with the catchment area SMX contamination, thus contributing to a better understanding of the retention/mobility of the ubiquitous sulfonamide antibiotic in high-altitude areas, and shed new light on the behavior of pharmaceuticals in poorly studied high-altitude environments like the Bolivian altiplano.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Retention of sulfamethoxazole in soils from a semiarid high altitudinal watershed: effect of soil type, soil organic matter, and pH

  • 期刊论文

  • 发表日期：

    2026年3月12日

查看全文
  • D. Archundia,
  • M. C. Morel,
  • C. Duwig,
  • L. Spadini,
  • B. Prado-Pano,
  • M. C. Soto-Barajas,
  • J. M. F. Martins

摘要

Purpose

Anthropized environments are known to be widely contaminated by pharmaceuticals, particularly antibiotics, through the spreading and dumping of contaminated water or animal wastes. However, little is known about contamination of high-altitude environments, such as the Bolivian Altiplano. The objective of this study was to evaluate the retention of the antibiotic sulfamethoxazole (SMX) in the Bolivian altiplano by measuring SMX sorption in 10 soils collected throughout the Katari watershed.

Methods

Sulfonamides (SA) are of interest due to their significant use and mobility in natural environments. The sorption and retention mechanisms of the antibiotic SMX were determined by sorption assays in ten soils with varying physical-chemical properties, collected throughout the Katari watershed. The role of organic matter in SMX retention was studied in more detail by characterizing the types of Soil Organic Carbon (SOC) in different soils using Differential Scanning Calorimetry (DSC) to compare the ratios of labile and recalcitrant components in the organic carbon of the soils studied.

Results

SMX sorption followed linear isotherms in all soils (r²>0.8), with sorption strength (Kd) varying greatly (0.16–16.0 L.kg− 1) and correlating with organic carbon (OC) content (Log(Koc) = 2.4+/-1.5). OC-rich soils—particularly those with more labile and recalcitrant fractions— showed higher SMX sorption by hydrophobic/π−π interactions, hydrogen-bonding, and metal complexation. Results showed that SMX sorption decreased with pH increase due to changes in SMX speciation (neutral/anionic). Neutral SMX, dominant in acidic soils, binds more effectively, whereas SMX− is subject to repulsion from negatively-charged soil surfaces. High nitrogen content possibly altered SOC composition (soils 5–10) increasing SMX-binding sites. Calculated R-factors suggest the presence of two soil groups in the watershed, soils 5–10 being highly vulnerable to SMX compared to soils 1–4.

Conclusion

This study permitted to determine SMX sorption parameters in the Katari watershed, which were used to predict SMX reactive transfer in the Altiplano over a wide range of conditions. The results are in line with the catchment area SMX contamination, thus contributing to a better understanding of the retention/mobility of the ubiquitous sulfonamide antibiotic in high-altitude areas, and shed new light on the behavior of pharmaceuticals in poorly studied high-altitude environments like the Bolivian altiplano.

Graphical Abstract