Hexavalent Chromium Removal from Drinking Water using Adsorption

Aquifers throughout the world are subject to groundwater contaminated with hexavalent chromium ions, which are highly toxic and difficult to remove. Adsorption is a method commonly used to eliminate unwanted materials from water; however, adsorptive removal of hexavalent chromium is challenging at neutral to slight basic conditions that are most relevant to drinking water treatment and distribution. In the present work, bench-scale experiments were performed to determine the performance of a suite of oxide materials on the adsorptive removal of hexavalent chromium ions. Both adsorption kinetics and isotherms were determined, and the impact of pH was also evaluated. Results suggested that several metal oxides showed excellent removal efficiency of chromate, and the adsorption capacity was highly dependent on solution pH. Both Langmuir and Freundlich isotherms fitted the experimental data well, and can be used for further studies. Potable water is one of the most important needs, yet it is also seems to be the most overlooked since it is often readily available at the turn of a handle. The design of a system that will reduce contaminants such as chromate in drinking water is a necessity in some households, and results from the present work may facilitate the design of an effective strategy for chromate removal from drinking water.