Removal of Cr(VI) from synthetic aqueous solutions by filamentous green algae Spirogyra porticalis

Abstract

A B S T R A C TApplication of various biomaterials to toxic compounds and heavy metals removal from aqueous solutions and industrial wastewaters is an efficient and low-cost method, in this regard macro and microalgae have revealed high potential for the biosorption of such metals. In this work, removal of Cr(VI) from synthetic aqueous solutions by powdered filamentous green algae Spirogyra porticalis was studied as an effect of various parameters including pH, biomass dosage, initial Cr(VI) concentration, and contact time in batch experiments. In order to do the statistical analysis, repeated measure test using SPSS 16.0 software was applied and p-value < 0.05 was considered as significant level. The results showed that the removal of Cr(VI) increased with the increase in the algal dosage, metal concentration, contact time, and decreasing pH. The optimum pH, biomass dose, initial concentration of Cr(VI), and contact time were found to be 3.0, 1 g/L, 40 mg/L, and 60 min, respectively. Under these conditions, the removal percentage of chromium(VI) and the specific removal capacity were found to be 70% and 27.48 mg/g, respectively. The findings of the present study indicated that S. porticalis can be used as an available, affordable, and efficient biosorbent to Cr(VI) removal from aqueous solutions and industrial acidic wastewaters containing high concentrations of chromium.