Arsenic adsorption from water : review of technologies and evaluation of natural and synthetic adsorbents

Abstract

Millions of people around the world are at risk of arsenic (As) poisoning. In present times, there have been countless research being conducted on As removal from water due to the gravity of the arsenic contamination situation around the world, especially in developing countries. Of exceptional promise was adsorption studies due to its relatively low level of technology, manpower, technical know-how and cost requirements.Iron oxides and granular activated carbon (GAC) are some of the better

adsorbents for pollutants removal from waste streams or contaminated water in the

market. However, iron oxides crumble easily and GAC does not seem to have a high

affinity for arsenic. It was proposed that an iron-impregnated GAC (GAC-Fe) would

be the key to synthesizing an adsorbent that has a high affinity for As and

mechanical stability for adsorption columns. Research has shown that an iron

concentration of 0.15M would result in a type of GAC-Fe that possesses a very high

As removal rate as well as long breakthrough time.