Biosorption of Cr(VI) by native isolate of Lyngbya putealis (HH-15) in the presence of salts

Industrial wastewaters containing heavy metals along with high concentration of soluble salts pose a major environmental problem that needs to be remedied. The present study reports on biosorption of Cr(VI) by native isolate of Lyngbya putealis HH-15 in batch system under varying range of pH (2.0-10.0), initial metal ion concentration (10-100 mg/l) and salt concentration (0-0.2%). Maximum metal removal (94.8%) took place at pH 3.0 with initial Cr concentration of 50 mg/l, which got reduced (90.1%) in the presence of 0.2% salts. Adsorption equilibrium and kinetic behavior of Cr(VI) in solution was also examined. Both Langmuir and Freundlich models fitted well to explain the adsorption data (R2 = 0.90 and 0.87, respectively) at 0.2% salt concentration. Pseudo-second order kinetic model also fitted well to both the systems, viz. Cr(VI) and Cr(VI) + salt.