Characterization and modeling of heavy metal removal by industrial biomass wastes

In this research work, several industrial biomass wastes were evaluated for their removal ability of solution heavy metal ions. Then the metal biosorption by brewery yeast waste (Saccharomyces cerevisiae), filamentous fungal waste and vitasoy waste were experimentally characterized. Further, three surface complexation models, including constant capacitance model (CCM), diffuse layer model and stern model, with different binding site combinations were evaluated for their applicability to simulate the metal biosorption data.; A yeast waste was found to exhibit good Cu(II) and Cr(III) removal capacities. Solution pH, anion and ionic strength were shown to affect biosorption. Langmuir and Freundlich models could well fit the isotherm data. The technique of scanning electron microscopy (SEM) coupled with energy dispersive analysis of X-ray (EDAX) showed that the Cu2+ and Cr3+ have exchanged with K+ on the yeast surface. The Fourier Transform Infrared (FT-IR) analysis and potentiometric titration simulation showed that RCOOH and RPO4H were potential biosorption sites. The two-site and one-site CCM were the best for simulating Cu(II) and Cr(III) biosorption, respectively.; A fungal waste was found to exhibit good Cu(II) and Cr(III) removal capacities. Different effects influencing the biosorption and isotherms were studied. The technique of SEM coupled with EDAX showed that the Cu2+ and Cr3+ have exchanged with K+ on this waste surface. The results of FT-IR analysis and potentiometric titration simulation showed that RCOOH, RPO4H and ROH were potential biosorption sites. An one-site CCM best simulated the biosorption data. EDTA treatment was demonstrated to enhance the Cr(VI) removal capacity by 30%.; Vitasoy waste was found to exhibit good Cr(III) removal capacity. Different effects influencing the biosorption and isotherms were studied. The technique of SEM coupled with EDAX showed that Cr3+ has exchanged with K+ and Ca2+ on this waste surface. Results of FT-IR analysis and potentiometric titration simulation suggested that RCOOH and RPO4H were potential biosorption sites. An one-site CCM best simulated the Cr(III) biosorption.; Bacterial isolates from local activated sludge, Pseudomonas pseudoalcaligenes and Micrococcus sp., showed good Pb(II), Cu(II) and Ni(II) removal capacities. A two-site CCM could well simulate the biosorption of single and binary metal systems.