SORPTION OF PHENOL BY SELECTED BIOPOLYMERS - ISOTHERMS, ENERGETICS, AND POLARITY

The behavior of phenol in the terrestrial environment is strongly regu lated by its reaction with soil components. We report here on the upta ke of phenol by soil minerals (goethite, kaolinite, and montmorillonit e) and by organics that may occur naturally in or be added to soil (tw o lignins, chitin, cellulose, collagen, and activated carbon). Our obj ectives were to determine the energetics and capacity for their uptake of phenol using batch equilibration, calorimetry, and CPMAS C-13 NMR and to evaluate the relation of organic carbon referenced sorption coe fficient (K(oc)) with the polarity of biopolymers. The biopolymers sor bed 2-45-fold more phenol than did the minerals. The K(d) for phenol u ptake by lignins with high aromaticity and low polarity were 4-6.5-fol d higher than that for chitin and 13-22-fold higher than that for cell ulose. Energy released during the formation of a putative donor-accept or complex on activated carbon was about 30 kJ/mol. Energy released fo r sorption of phenol by biopolymers ranged from 5 to 20 kJ/mol. The K( oc) of phenol decreased with increasing polarity: (N + O)/C of the bio polymers. We infer that the K(oc) of organic compounds may not be adeq uately predicted from their K(ow) without considering the nature of or ganic matter.