Adsorption kinetics of the antibiotic ciprofloxacin on bentonite, activated carbon, zeolite, and pumice

Adsorptive removal of antibiotics from water and wastewater: Progress and challenges

“…In batch mode, the adsorption of ciprofloxacin from aqueous solution on bentonite was found to be very high with 99% removal efficiency, with a contact time of 30 min at pH 4.5 (Genç et al, 2013). In another study (Table 4) for the removal of ciprofloxacin on using bentonite, AC, zeolite and pumice, it was observed that bentonite achieved the highest removal capacity (Genç and Dogan, 2015). They also calculated the Gibbs free energy (ΔG°) values of adsorption by bentonite, zeolite, AC and pumice which appeared in the order: bentonite N AC N zeolite N pumice.…”

“…In a batch kinetic study for the adsorption of sulfamethazine on bentonite (Table 7a), it was found that 120 min was needed to reach an equilibrium (Fernández et al, 2014b). For adsorptive removal of ciprofloxacin (Table 7b) on bentonite, AC, zeolite and pumice, it was observed that the pseudo second order kinetic model was the best model for fitting the data with r 2 value of 0.999 (Genç and Dogan, 2015). The equilibrium time (Table 7a) for batch adsorptive removal on strong anion exchanger was found to be 120 min and 100 min, respectively for sulfamethoxazole and sulfamethazine, and for sulfamethazine (Fernández et al, 2014a,b), which is relatively fast for the adsorption process.…”

“…For example, in studying the adsorption of 40 mg/L of ciprofloxacin using bentonite and AC, negative ΔG°values (−4340 and −843 J/mol), positive ΔH°v alues (8662 and 7739 J/mol), and positive ΔS°values (44.1 and 29.1 J/mol K) were observed for bentonite and AC, respectively at 22°C. The results indicated that some structural changes were occurring on the adsorbent surfaces, and the randomness at the solid-liquid interface was increased during the adsorption process (Genç and Dogan, 2015).…”

“…FQ molecules appear to be better suited for cation exchange than for cation bridging or surface complexion. At pH 4.5, cation exchange between the protonated heterocyclic (N atom) of positively charged ciprofloxacin (CIP + ) and negatively charged montmorillonite surface occurred at pH 7.0, the carboxylic anion was the dominant species and thus carboxylic group of negatively charged ciprofloxacin (CIP − ) interacted with montmorillonite surface (Genç and Dogan, 2015;Pei et al, 2009;Yan et al, 2013b).…”

Treatment technologies for emerging contaminants in water: A review

“…Other adsorbent materials may also perform relatively well in the removal of ECs. For example, zeolite or pumice for the removal of ciprofloxacin[93] or the use of alum oxide in the adsorption of different antibiotics with variable removal results ranging from 43 to 90%[54,102] and the application of molecularly imprinted polymers and materials of diverse nature for the removal of a variety of pharmaceuticals[104][105][106][107][108].…”