Adsorption of phenol and o-chlorophenol by mesoporous MCM-41.
ABSTRACT Water pollution by toxic organic compounds is of concern and the demand for effective adsorbents for the removal of toxic compounds is increasing. Present work deals with the adsorption of phenol (PhOH) and o-chlorophenol (o-CP) on mesoporous MCM-41 material. The effect of surfactant template in MCM-41 on the removal of PhOH and o-CP was investigated. The comparison of adsorption of PhOH and o-CP on uncalcined MCM-41 (noted as MCM-41) and calcined MCM-41 (noted as C-MCM-41) was investigated. It was found that MCM-41 shows significant adsorption for PhOH and o-CP as compared to C-MCM-41, this may be because of the hydrophobicity created by surfactant template in the MCM-41. Batch adsorption studies were carried out to study the effect of various parameters like adsorbent dose, pH, initial concentration and the presence of co-existing ions. It was found that adsorption of PhOH and o-CP depends upon the solution pH as well as co-existing ions present in the aqueous solution. The equilibrium adsorption data for PhOH and o-CP was analyzed by using Freundlich adsorption isotherm model. From the sorption studies it was observed that the uptake of o-CP was higher than PhOH.
[show abstract] [hide abstract]
ABSTRACT: The effects of the biosurfactant monorhamnolipid (monoRL) and the chemical surfactant Tween 80 on the degradation of phenol by Candida tropicalis CICC 1463 were studied. Both surfactants impeded the decay in cell concentrations at the beginning of the fermentation and enhanced the cell growth thereafter. They also increased the degradation efficiencies of 500 mg/L phenol from 86.9% in control to above 99.0% for all test concentrations within 30 h. The monoRL could also be degraded by the C. tropicalis. These results indicate that the surfactants could diminish the toxicity of phenol to the yeast, increase cell growth and improve phenol removal. The monoRL is better than Tween 80 because of biodegradability.Process Biochemistry. 01/2010;
Article: Adsorption of Phenolic Compounds from Aqueous Solutions onto Chitosan-Coated Perlite Beads as Biosorbent[show abstract] [hide abstract]
ABSTRACT: Chitosan-coated perlite (CCP) beads were prepared by dropwise addition of a liquid slurry containing chitosan and perlite to an alkaline bath. The resulting beads were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and surface area analysis. The chitosan content of the beads is 23% as determined by a pyrolysis method. Adsorption of phenolic compounds (phenol, 2-chlorophenol, and 4-chlorophenol) from aqueous solutions on chitosan-coated perlite beads was studied under batch equilibrium and column flow conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate, and dosage of adsorbent. Adsorption kinetic and isotherm studies, respectively, showed that the adsorption process followed a pseudo-first-order kinetic model and the Langmuir isotherm. The maximum monolayer adsorption capacity of phenol, 2-CP, and 4-CP on to the chitosan-coated perlite beads was found to be 192, 263, and 322 mg g -1 , respectively.Industrial & Engineering Chemistry Research 05/2010; · 2.24 Impact Factor