Adsorption of bacteriophages on clay minerals

The ability to predict the fate of microorganisms in soil is dependent on a n understanding of the process of their sorption on soil and subsurface mat erials. Presently, we have focused on studying the thermodynamics of sorpti on of bacteriophages (T-2, MS-2, and phi X-174) on clays (hectorite, saponi te, kaolinite, acid clay fraction of samples collected from a landfill site ). The thermodynamic study not only determines the feasibility of the proce ss but also provides information on the relative magnitudes of the differen t forces under a particular set of conditions. The total free energy of int eraction during sorption of bacteriophages on clays (Delta G) has been assu med to be the summation of Delta G(H) (Delta G due to hydrophobic interacti ons) and Delta G(EL) (Delta G due to electrostatic interactions). The magni tude of Delta G(H) was determined from the different interfacial tensions ( gamma) present in the system, while Delta G(EL) was calculated from zeta-po tentials of the colloidal particles. Calculated results show that surface h ydrophobicities of the selected sorbents and sorbates dictate sorption. Amo ng the selected bacteriophages, maximum sorption was observed with T-2, whi le hectorite has the maximum sorption capacity. Experimental results obtain ed from the batch adsorption studies also corroborated those obtained from the theoretical study.