Arsenic removal from water/wastewater using adsorbents—A critical review

Two of the greatest challenges facing the 21st century involve providing sustainable supplies of clean water and energy, two highly interrelated resources, at affordable costs. Membrane technology is expected to continue to dominate the water purifica- tion technologies owing to its energy efficiency. However, there is a need for improved membranes that have higher flux, are more selective, are less prone to various types of fouling, and are more resistant to the chemical environment, especially chlorine, of these processes. This article summarizes the nature of the global water problem and reviews the state of the art of membrane technology. Existing deficiencies of current membranes and the opportunities to resolve them with innovative polymer chemistry and physics are identified. Extensive background is provided to help the reader understand the fundamental issues involved. V C 2010 Wiley Periodi- cals, Inc. J Polym Sci Part B: Polym Phys 48: 1685-1718, 2010

Water Purification by Membranes: The Role of Polymer Science

https://www.ircwash.org/sites/default/files/Ng-2003-Global.pdf

A global health problem caused by arsenic from natural sources

Laboratory based approaches for arsenic remediation from contaminated water: recent developments.

Removal of arsenic from contaminated water sources by sorption onto iron-oxide-coated polymeric materials.

Arsenic in drinking water-problems and solutions

The current United States maximum contaminant level for arsenic in drinking water is set at 50 μg/l. Because of the cancer risks involved, Canada has already lowered the maximum contaminant level to 25 μg/l; the United States Environmental Protection Agency is reviewing the current allowable level for arsenic with a view of lowering it significantly. Various treatment methods have been adopted to remove arsenic from drinking water. These methods include 1) adsorption-coprecipitation using iron and aluminum salts, 2) adsorption on activated alumina, activated carbon, and activated bauxite, 3) reverse osmosis, 4) ion exchange and 5) oxidation followed by filtration. Because of the promise of oxidation-filtration systems, column studies were conducted at the University of Regina to examine oxidation with KMnO 4 followed by filtration using manganese greensand and iron-oxide coated sand to examine the removal of arsenic from drinking water; these results were compared with the data from ion exchange studies. These studies demonstrated that As (III) could be reduced from 200 μg/l to below 25 μg/l by the manganese greensand system. In the case of manganese greensand filtration, addition of iron in the ratio of 20:1 was found necessary to achieve this removal.

K. S. Subramanian

Papers

Arsenic in drinking water-problems and solutions

Arsenic in drinking water: problems and solutions.