Adsorption and bio-degradation of phenol by chitosan-immobilized Pseudomonas putida (NICM 2174)

Abstract

Biodegradation of phenol by Pseudomonas putida (NICM 2174), a potential biodegradent of phenol has been investigated for its degrading potential under different conditions. Pseudomonas putida (NICM 2174) cells immobilized in chitosan were used to degrade phenol. Adsorption of phenol by the chitosan immobilized matrix played an important role in reducing the toxicity of phenol. In the present work, results of the batch equilibrium adsorption of phenol on chitosan from its aqueous solution at different particle sizes (0.177 mm, 0.384 mm, 1.651 mm) and initial concentration of phenol (20,40,60, 80, 100, 120, 140, 160, 180, 200 mg/l) have been reported. The adsorption isotherms are described by Langmuir, Freundlich and Redlich-Peterson types of equations. These indicate favourable adsorption with chitosan. From the adsorption isotherms, the adsorption capacity, energy of adsorption, number of layers and the rate constants were evaluated. In batch kinetic studies the factors affecting the rate of biodegradation of phenol, were initial phenol concentration (0.100 g/l, 0.200 g/l, 0.300 g/l), temperature (30°C, 34°C, 38°C) and pH (7.0, 8.0, 9.0). Biodegradation kinetic data indicated the applicability of Lagergren equation. The process followed ®rst order rate kinetics. The biodegradation data generally ®t the Lagergren equation and the intraparticle diffusion rate equation from which adsorption rate constants, diffusion rate constants and diffusion coef®cients were determined. Intraparticle diffusion was found to be the rate-limiting step. Cell growth contributed signi®cantly to phenol removal rates especially when the degradation medium was supplemented with a utilizable carbon source.

Chemically treated kola nut pod as low-cost natural adsorbent for the removal of 2,4-dinitrophenol from synthetic wastewater: batch equilibrium, kinetic, and thermodynamic modelling studies

“…It is seen that the biosorption capacity of kola nut pods increased with decrease in particle size diameter; thus, the removal of 2,4-DNP increases as the particle size diameter decreases (Figure 2a). Similar observations have been reported for adsorption of unsubstituted phenol [44] and the biosorption of 2,6-dichlorophenol [39]. Decrease in particle size increases the percentage removal (Figure 2b) due to increase in surface area as well as micropore volume [45].…”

“…Smaller particle size means more interior surface and micropore volume, and hence the area of active sites for adsorption will be greater. Additionally, for larger particles, the diffusion resistance to mass transfer is higher and most of the internal surfaces of the particle may not be utilized for adsorption; consequently, the amount of 2,4-DNP adsorbed is small [44,46]. …”

Enhancement of a two‐phase partitioning bioreactor system by modification of the microbial catalyst: Demonstration of concept

“…Phenol is a toxic, highly water-soluble compound utilized in nylon production, and commonly found in the euents from coking and petroleum manufacturing plants. The extensive production and use of phenols in industry has resulted in wastewaters containing phenolic concentrations ranging as high as 3 g/L (Annadurai et al, 2000) and, consequently, phenol has been classi®ed as a priority pollutant by both Canadian and U.S. environmental protection organizations (Canadian Environmental Protection Agency, 2001; U.S. Environmental Protection Agency, 1998).…”

Adsorption of phenol on natural clay

“…(Rengaraj et al 2002a, b) used activated carbon prepared from rubber seed coat for phenol adsorption. Different porous materials like activated carbon cloth, activated carbon fiber, Ca-alginate beads, diatomaceous earth, denatured biomass, chitosan material (Annadurai et al, 2000), Na-Alginate, ion exchange resin, clay, etc. have been used for adsorption.…”