Biosorption efficiency of syzygium cumini (l.) bark for removal of hexavalent chromium from contaminated waters

TLDR: In this paper, an adsorbent has been prepared from Syzygium cumini (L.) bark and studies are carried out for chromium (VI) removal from industrial wastewaters.

Abstract: Heavy metals such as chromium, mercury, lead, cadmium, etc., in wastewater are hazardous to the environment because of their toxicity and pollution effects on our ecosystem. Among the different heavy metals, chromium (VI) is a common and very toxic pollutant introduced into natural waters from a variety of industrial wastewaters. The Chromium (VI) discharged from various industries has potential to contaminate drinking water sources and is one of the most important environmental problems due to its health impacts on human. Adsorption is one of the effective techniques for chromium (VI) removal from wastewater. In the present study, adsorbent has been prepared from Syzygium cumini (L.) bark and studies are carried out for chromium (VI) removal. The parameters investigated in this study are contact time, adsorbent dosage, temperature, variable initial chromium (VI) concentration and pH using Diphenyl carbazide as color developing reagent and taking the absorbance at 540 nm spectrophotometrically. The adsorption process of chromium (VI) is tested with Linear, Langmuir and Freundlich isotherm models. Application of the Langmuir isotherm to the systems yielded maximum adsorption capacity of 31.51 mg/g at a solution pH of 7 having Cr (VI) concentration 50 mg/L and biosorbent dose 1g/L. The adsorption of chromium (VI) was found to be maximum 95.63% at low pH values of 2 having Cr (VI) concentration 50 mg/L and biosorbent dose 1g/L. The contact time of 60 min resulted to the 55.28% adsorption of metal in 50mg/L solution using adsorbent dose of 1g/L and can used for removal of chromium (VI) from the polluted water as a very low cost biosorbent. The FTIR carried out shows the increase in intensity of adsorption peaks of biosorbent after hexavalent chromium adsorption.