The Removal of Lindane from Aqueous Solution using a Fungal Biosorbent: The Influence of pH, Temperature, Biomass Concentration, and Culture Age

Abstract

A heat treated non viable cell suspension of the fungus Rhizopus oryzae was used for the removal of low concentrations of lindane from aqueous solution in a series of shake flask experiments. Experimental design was such as to allow the data to be tested against the Freundlich adsorption isotherm model thus quantifying the effect of experimental variables on both the adsorption capacity and intensity of adsorption exhibited by the fungus. The effects of temperature (5–45°C), pH (2.0–10), biomass density (1–12 g l⁻¹) and biomass age (1–7 days) were studied. The results indicated that the mechanism of adsorption was by physical bonding of the negatively charged lindane molecule to the negatively charged fungal cell wall with hydrogen ions acting as the bridging ligand. Adsorption was most effective at low temperature and pH and was shown to be influenced, to a lesser extent, by cell density and biomass age. Data are presented in the form of adsorption isotherms and the Freundlich parameters associated with each of the experimental variables tabulated.

Keywords:

• Biosorption
• lindane
• fungal