Priti A. Mangrulkar

Adsorption of phenol and o-chlorophenol by mesoporous MCM-41

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.

Photocatalytic Degradation of Phenolics by N-Doped Mesoporous Titania under Solar Radiation

In this study, nitrogen-doped mesoporous titania was synthesized by templating method using chitosan. This biopolymer chitosan plays the dual role of acting as a template (which imparts mesoporosity) and precursor for nitrogen. BET-SA, XRD, UV-DRS, SEM, and FTIR were used to characterize the photocatalyst. The doping of nitrogen into TiO2 lattice and its state was substantiated and measured by XPS. The photocatalytic activity of the prepared N-doped mesoporous titania for phenol and o-chlorophenol degradation was investigated under solar and artificial radiation. The rate of photocatalytic degradation was observed to be higher for o-chlorophenol than that of phenol. The photodegradation of o-chlorophenol was 98.62% and 72.2%, while in case of phenol, degradation to the tune of 69.25% and 30.58% was achieved in solar and artificial radiation. The effect of various operating parameters, namely, catalyst loading, pH, initial concentration and the effect of coexisting ions on the rate of photocatalytic degradation were studied in detail.