Biosorption of Cu^2+ by Eichhornia crassipes: Physicochemical characterization, biosorption modeling and mechanism

This work presents the biosorption potential eichhornia crassipes biomass, collected from the nile water, for removing cu(ii) ions. physicochemical characteristics, proton and cu^2+ binding constants, and biosorption isotherms were studied. the biomass contains 43.3 mg g1 protein, 40.76 mg g^-1 carbohydrates and 16 types of amino acids. the biomass has large surface area (4.16 m^2 g^-1) and pore size (35.93 a˚ ). proton bindings (pkh1 =1.8; pkh2 = 1.9; pkh3= 2.0) and cu^2+ binding constants (pkm1 =4.37; pkm2= 4.24; pkm3= 3.76) were calculated by non-ideal competitive absorption (nica) model. ft-ir results suggested that aoh, acooh and ap‚o sites are mainly responsible for cu^2+ biosorption. biosorption isotherms were successfully fitted by two langmuir linearization models. the biosorption mechanism includes ionization and complexation stages. the biomass shows a breakthrough ability for cu^2+ biosorption (qmax = 27.7 mg g^-1) and at ph 4.5.