RESUMO
The potential to remove Cr (VI) from aqueous solutions through biosorption using the husk of Bengal gram (Cicer arientinum), was investigated in batch experiments. The results showed removal of 99.9 percent of chromium in the 10 mgl-1 chromium solution, the biomass required at saturation was 1 g mg-1. Kinetic experiments revealed that the dilute chromium solutions reached equilibrium within 180 min. The biosorptive capacity of the (bgh) was dependent on the pH of the chromium solution, with pH 2 being optimal. The adsorption data fit well with the Langmuir and Freundlich isotherm models. The adsorption capacity calculated from the Langmuir isotherm was 91.64 mg Cr (VI)/g at pH 2. The adsorption capacity increased with increase in agitation speed and an optimum was achieved at 120 rpm. The biosorption of Cr (VI) was studied by Fourier transform infrared spectroscopy (FTIR), which suggested that the presence of Cr (VI) ions in the biomass affects the bands corresponding to hydroxyl and carboxyl groups. Comprehensive characterisation of parameters indicates bgh to be an excellent material for biosorption of Cr (VI) to treat wastewaters containing low concentration of the metal.
Assuntos
Cicer/metabolismo , Cromo/metabolismo , Purificação da Água/métodos , Adsorção , Agricultura , Biodegradação Ambiental , Biomassa , Cicer/química , Cromo/química , Espectroscopia de Infravermelho com Transformada de Fourier , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Soluções , TemperaturaRESUMO
Phytochelatins and related metabolites (cysteine and GSH) were found to be induced in the shoots of two varieties of Cicer arietinum viz., CSG-8962 and C-235 grown under different amendments of fly-ash with garden soil and press mud. Cysteine, GSH, PCs and its speciation were found in higher concentrations in amended fly-ash than in the control 100% soil. Two species of metal binding peptides i.e., PC2 and PC4 were found in both varieties and in amendments, however, their concentration varied depending upon the fly-ash concentrations in both amendments. Further, var. CSG-8962 was found more tolerant than var. C-235 because of higher concentrations of PCs and related metabolites.