Bentonite for ciprofloxacin removal from aqueous solution

Abstract

Ciprofloxacin hydrochloride (CIP) is the second generation of fluoroquinolone antibiotics whose residues are found in wastewater and surface water. CIP has high aqueous solubility under different pH conditions and high stability in the soil system. In this study, bentonite was used as a potential sorbent for the removal of CIP from aqueous solutions using batch experiments. The effects of various parameters such as contact time, pH, adsorbent dosage, agitation speed, ionic strength and initial concentration of CIP in aqueous solution on the adsorption capacity were investigated. The optimum contact time, pH, agitation speed and adsorbent dosage were found to be 30 min, 4.5 pH, 150 rpm and 2.5 g L(-1), respectively. When the ionic strength was increased from 5 to 50 mM, the adsorption of CIP decreased from 97.8 to 93.4%. The isotherm adsorption data fitted well with the Langmuir model, Kl and qe were found to be 0.27 L mg(-1) and 147.06 mg g(-1), and the data fitted well with the pseudo-second order kinetics, whereby k was found to be 2.19 g mg(-1) h(-1).

Influence of pH and antibiotic solubility on the removal of ciprofloxacin from aqueous media using montmorillonite

“…55, 7.4, 33, 112, 135, and 300 mg of CPX per gram of adsorbent by modified coal fly ash, kaolinite, illite, carbon xerogel, rectorite, carbon nanotubes and activated carbon, respectively Wang et al, 2011;Zhang et al, 2011;Carabineiro et al, 2012). However, the results obtained for adsorption of CPX on montmorillonites showed higher adsorption capacities Genç et al, 2013).…”

“…These adsorbents have not only proved to be effective, but also widely distributed, affordable and environmentally friendly materials (Grassi et al, 2012). Consequently, clay minerals have been applied for the removal of many different organic compounds as dyes (Rytwo et al, 2000), pesticides (Polatti et al, 2006) and antibiotics (Putra et al, 2009;Molu and Yurdakoç, 2010;Genç et al, 2013). Particularly, the bentonites located in the Alto Valle de Río Negro-Neuquén, Argentina have showed to be good adsorbents for the removal of thiabendazole fungicide (Roca and the tetracycline antibiotic (Parolo et al, 2008) from aqueous media.…”

Investigation of ciprofloxacin removal from aqueous solution by nanofiltration process

“…When the solution pH is above 8.89, the anionic form CIPRO -prevails due to loss of a proton from the carboxylic group. When solution pH is between 5.90 and 8.89, the zwitterionic form CIPRO 0 resulting from the charge balance of the two groups mentioned above is the dominant species (Genç at al., 2013). The physico-chemical properties of CIPRO were summarized in Figure 1.…”

“…CIPRO concentrations between 0.7 and 124.5 µg l -1 in hospital effluent (Jiang et al, 2012;Genç et al, 2013), between 249 and 405 ng l -1 in wastewater treatment plants have been reported (Zaviska et al, 2013). CIPRO was found in wastewater treatment plant effluents at concentrations of 313-568 ng l -1 and up to 124.5 µg l -1 in hospital sewage water (De Witte et al, 2009).…”

“…A number of promising wastewater treatment technologies have been used for removing CIPRO from wastewater, such as sorption and adsorption (Wu et al, 2010;Jiang et al, 2013a;Rakshit et al, 2013;Genç et al, 2013;Wu et al, 2013), membrane separation (Sun et al, 2011;Zaviska et al, 2013;Urtiaga et al, 2013), ozonation, oxidation and other photocatalytic degradation processes (De Witte et al, 2009;Vasconcelos et al, 2009;De Witte et al, 2010;Jiang et al, 2012;Jiang et al, 2013b;Zhou and Jiang, 2015). Notwithstanding the differences between degradation mechanisms of these oxidation processes, the byproducts formed may be the same, or at least, similar to each other (Vasconcelos et al, 2009).…”