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Nitroimidazoles adsorption on activated carbon cloth from aqueous solution
R Ocampo-Pérez1, F Orellana-Garcia, M Sánchez-Polo
1Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
Journal of Colloid and Interface Science
|April 30, 2013
Summary
Activated carbon cloth (ACC) effectively adsorbs nitroimidazoles from water, with adsorption influenced by pH and water type. Intraparticle diffusion controls the adsorption rate, highlighting ACC
Area of Science:
- Environmental Chemistry
- Materials Science
- Adsorption Science
Background:
- Nitroimidazoles are emerging contaminants found in various water sources.
- Activated carbon cloth (ACC) is a promising adsorbent material for water treatment.
Purpose of the Study:
- To investigate the adsorption equilibrium and kinetics of nitroimidazoles on ACC.
- To determine the key interactions and diffusion mechanisms governing nitroimidazole adsorption.
- To evaluate the impact of operational variables and water matrices on adsorption.
Main Methods:
- Adsorption experiments were conducted using ACC and nitroimidazoles (dimetridazole, metronidazole).
- The influence of pH, ionic strength, temperature, and water type (ultrapure, surface, wastewater) was assessed.
- Kinetic models were applied to elucidate the adsorption rate-limiting step.
- ACC surface modifications were performed to study surface chemistry effects.
Main Results:
- ACC demonstrated high nitroimidazole adsorption capacity in aqueous solutions.
- Electrostatic interactions were significant at pH<3, while hydrogen bonding and dispersive forces dominated at higher pH.
- ACC surface chemistry, modified by NH3, K2S2O8, and O3, critically influenced adsorption.
- Adsorption was higher in surface water than in urban wastewater due to differences in alkalinity and dissolved organic matter.
- Intraparticle diffusion was identified as the rate-limiting step for nitroimidazole adsorption.
Conclusions:
- ACC is an effective adsorbent for nitroimidazoles, with adsorption governed by a combination of electrostatic, hydrogen bonding, and dispersive interactions.
- Surface chemistry modifications and water matrix composition significantly impact ACC's adsorption performance.
- The adsorption process is primarily controlled by intraparticle diffusion, suggesting pore diffusion limitations.
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