Journal des sciences et de l'ingénierie des matériaux

Removal of Chromium from Industrial Wastewater by Adsorption Using Coffee Husk

Abstract

Dessalew Berihun

Fresh water is vital to human life and economic well-being, and societies extract vast quantities of water from rivers, lakes, wetlands, and underground aquifers but most of these freshwater sources are polluted by different chemicals discharged from industries. Our need for fresh water has long caused us to overlook equally vital benefits of water that remains in streams to sustain healthy freshwater habitats. Heavy metals are discharged from different industries into freshwaters and are easily absorbed by fish and other aquatic organisms. Small concentrations can be toxic because heavy metals undergo bio concentration. Chromium is an essential element that is required in small amounts for carbohydrate metabolism, but becomes toxic at higher concentrations. The most bioavailable and therefore most toxic form of chromium is the hexavalent Cr (VI) ion. It is well recognized as an element of environmental and public health concern. The objective of this study was to examine the potential of coffee husk in removing chromium from polluted water. In this study, the adsorption potential of activated carbon for the removal of Cr (VI) ions from industrial wastewater has been investigated. The adsorption of hexavalent chromium from aqueous solution by coffee husk activated carbon prepared by chemical method and its application to real wastewater was studied. The extent of adsorption was studied as a function of pH, contact time, adsorbent dose, and initial adsorbed concentration. Optimum results were found to be 60 min, 80 mg/l, 2 g/l, 3 g/l and 200 rpm for time contact, initial concentration, pH, adsorbent dose and stirring speed respectively at the optimal condition the adsorption of hexavalent chromium was found to be 98.19%.