Chitosan cross-linked β-cyclodextrin polymeric adsorbent for the removal of perfluorobutanesulfonate from aqueous solution: adsorption kinetics, isotherm, and mechanism

Enhanced PFBS adsorption via silver-impregnated activated carbon: Mechanistic insights and Thermodynamic analysis

This study investigates the effect of silver nanoparticle impregnation on the performance of activated carbon (AC) for perfluorobutane sulfonic acid (PFBS) adsorption. Using the deposition-precipitation method, three silver-impregnated activated carbon (SIAC) adsorbents were synthesized with varying silver contents: SIAC0.01 (0.15 wt%), SIAC0.1 (1.7 wt%), and SIAC1 (8.5 wt%). Among these, SIAC0.1 exhibited the highest adsorption capacity at 25 °C and was selected for detailed analysis. The adsorption mechanism of PFBS on SIAC0.1 was examined at 25, 35, and 45 °C, yielding key kinetic parameters, including reaction rate constants and activation energies. Additionally, the thermodynamic properties of the adsorption process, including ΔH≠, ΔS≠, and ΔG≠, were evaluated. The findings reveal that silver nanoparticle impregnation significantly enhances the kinetic and thermodynamic favorability of PFBS adsorption, leading to a substantial increase in adsorption capacity. This work highlights the potential of silver-impregnated activated carbon as an effective adsorbent for PFBS removal.

Adsorption of emerging pollutants utilizing chitosan derivatives: Recent advances and future perspective

Globalization resulted in technological advancement, and urban population growth. Consequently, pollution emerged as an imminent risk to the survival of all species on Earth. Consequently, on a worldwide basis, sustainability become a major issue for legislators. Inconsistent impacts on both human and animal growth and wellness triggered health issues associated with water contamination through the chronic toxicants. Micropollutants' pollution prompted severe concerns due to their malignant, indestructible, and accumulative properties. The elimination of these toxins from industrial processes has become one of the most significant ecological challenges. A variety of both organic and simulated sorbents are available, and each of these have unique benefits. In the recent years, chitosan and its composite materials have been attempted and have been proven to be applicable for the resolution of many challenging issues related to water pollution. Among various notable benefits of adsorption processes, economic viability, ease of access, and adherence to environmental regulations are notable. Considering the above-mentioned issues, the article targets the assessment of chitosan and its composite materials for relevant environmental applications. Accordingly, the article aims to examine the performance, advantages, and disadvantages of chitosan as an adsorbent.

Green surface functionalization of chitosan with spent tea waste extract for the development of an efficient adsorbent for aspirin removal

This study investigates the feasibility of spent tea waste extract (STWE) as a green modifying agent for the modification of chitosan adsorbent towards aspirin removal. Response surface methodology based on Box-Behnken design was employed to find the optimal synthesis parameters (chitosan dosage, spent tea waste concentration, and impregnation time) for aspirin removal. The results revealed that the optimum conditions for preparing chitotea with 84.65% aspirin removal were 2.89 g of chitosan, 18.95 mg/mL of STWE, and 20.72 h of impregnation time. The surface chemistry and characteristics of chitosan were successfully altered and improved by STWE, as evidenced by FESEM, EDX, BET, and FTIR analysis. The adsorption data were best fitted to pseudo 2nd order, followed by chemisorption mechanisms. The maximum adsorption capacity of chitotea was 157.24 mg/g, as fitted by Langmuir, which is impressive for a green adsorbent with a simple synthesis method. Thermodynamic studies demonstrated the endothermic nature of aspirin adsorption onto chitotea.