Use of chelating water insoluble thiols for the removal of arsenic from water

ENVR 48

Niladri N. Gupta, niladri.gupta@uky.edu, E. Railey White, railey.white@gmail.com, and David Atwood, Datwood@uky.edu. Department of Chemistry, University of Kentucky, Lexington, KY 40506
Research at the University of Kentucky has revealed that a series of water-insoluble thiolates can be dispersed in a column containing silica to remove both arsenite and arsenate under a variety of conditions. The system was tested with water containing 300 ppb arsenic. The filtered samples had less than 10ppb arsenic. The arsenic binding media is created from inexpensive proprietary thiol compounds. An example of one such compound is benzenediethanethiol (BDT) which is an University of Kentucky-patented class of compounds that has been shown to irreversibly bind Hg under a wide range of laboratory conditions as well is in the field. Mercury and arsenic are “soft” elements and form strong bonds to sulfur. In fact, the bonding of arsenic to sulfur (~370kJ/mol) greatly exceeds the bonding to mercury (~ 200kJ/mol). It is anticipated that BDT would bind arsenic in a manner similar to mercury.