Assessment of Food Waste as Suitable Adsorbent for Removal of Chromium (vi) from Synthetic Waste Water

Abstract

AbstractEffluents from industries have created a congregation of mayhem worldwide as they carry a lot of heavy and virulent metals with them and contaminate the water when discharged to any water body. As per many sources effluents from industrial processes such as electroplating, mining, nuclear power operation, battery manufacturing, dye and pigments have been identified to contain high level of heavy metals and some heavy metals include Cr(III), Cr(VI), Zn, Cd, Cu, Ni, Hg and pb. Chromium as a metal has long been used in electroplating, leather tanning, metal finishing and many other manufacturing industries. It is found that effluents from these industries contain both trivalent chromium Cr(III), and hexavalent chromium Cr(VI) with concentrations ranging from tens to hundreds of mg/L. The aim of the current research work was pertinent to find a suitable sorbent for removal of chromium from waste water. Therefore naturally available resources like rice husk, saw dust, tea powder waste, banana peel and vegetable peel wastes viz. potato and carrot peel from kitchens are used as adsorbent for this study. A relative comparative study was done considering the effect of sorbent dose, sorbent concentration, pH of the solution and shaking time. Different adsorption isotherms was used to reckon the maximum uptake capacity. It was found from the study that percentage of metal uptake increased with the increase in sorbent dose, sorption of chromium increases with increase in pH for rice husk, tea waste, vegetable peels and decreased with increase in pH for saw dust and banana peel. Sorption of chromium was found to increase with increase in contact time specifically contact time is more for tea waste. Vegetable peel used was found to be more efficient in the adsorption of the metal ions than other adsorbents being used for this study. The results obtained from this work distinctly proved the efficacy of rice husk, saw dust, tea waste, banana peel and vegetable peel as effective adsorbents for chromium removal.KeywordsAdsorbentSorptionConcentrationDoseChromium