Effectively removing tetracycline from water by nanoarchitectured carbons derived from CO2: Structure and surface chemistry influence

Understanding of the correlation between physico-chemical property of adsorbent and the adsorption performance of contaminant is very significant for developing high-efficient materials to remove antibiotic contamination from water. In this work, a novel kind of carbon adsorbent (EC) derived from CO2 and activated ECs with modified structure via a facile chemical method using H-2 and KOH were prepared. The synthetic carbon materials (EC, EC-H-2, and EC-KOH) were then applied to remove tetracycline (TC). The kinetics of adsorption for these three carbon materials all well fitted the pseudo-second-order kinetic model. The experimental data of adsorption isotherm had good compatibility with Langmuir and Freundlich models (R-2 > 0.90), but the Temkin model was the most applicable for all adsorbents (R-2 > 0.98). A super-high adsorption capacity of EC-KOH obtained from Langmuir fitting was 933.56 mg g(-1), which was much higher than that of EC-H-2 (538.91 mg g(-1)) and EC (423.30 mg g(-1)), possibly due to its larger specific surface area (SBET), pore volume, and specific surface chemical structure. Moreover, it was found that surface functional groups and large aperture of adsorbents had a positive effect on adsorption rate. More adsorption sites and surface functional groups of adsorbents were beneficial to enhance the adsorption affinity. These results are of great benefit to the directional control of carbon structure to increase the adsorption performance in rate, capacity, and affinity of antibiotics.

Automated summary

Understanding the correlation between the physico-chemical properties of adsorbents and the adsorption performance of contaminants is crucial for the development of efficient materials for removing antibiotic contamination from water. In this study, novel carbon adsorbents were synthesized and modified to enhance their adsorption capacity for tetracycline. Results showed that surface functional groups and large pores of adsorbents positively affected the adsorption rate, while more adsorption sites and surface functional groups improved the adsorption affinity. These findings provide valuable insights for directing the control of carbon structure to enhance adsorption performance in terms of rate, capacity, and affinity for antibiotics.