Proton competition in Cu(II) adsorption by fungal mycelia

摘要: Fungal mycelia have been shown to be effective adsorbents for the removal of heavy metals from dilute solutions. Copper ions and protons become adsorbed fungal surface through reaction with specific sites including amino-, phosphate, carboxyl- or hydroxo-groups. In this study, an alkalimetric/metal titration technique was used evaluate competitive adsorption between Cu(II) onto acid-washed Aspergillus oryzae Rhizopus oryzae. A general macroscopic mechanism has established describe both ions. Using a simple graphic non-linear least squares technique, parameters; i.e. constant maximum capacity, were evaluated. The results predicted by two-site model double reciprocal plot Scatchard compared regression. presence multiple classes sites, better fit experimental data obtained treating as one which possesses two major functional groups, namely: (1) high affinity monodentate binding, (2) low bidentate binding. Because hydrogen compete significantly Langmuir isotherm so derived characterized three parameters: affinity, density apparent proton affinity. This enabled differentiation protons. Two intrinsic equilibrium constants complexation estimated. With information, it possible predict over wide range metal loading conditions at various pH values.