NEW TECHNOLOGIES FOR ARSENIC CONTAMINATED DRINKING WATER REMEDIATION.
Susan Murcott, Jessica Hurd, Tommy Ngai, Barika Poole.
Department of Civil and Environmental Engineering,
Massachusetts Institute of Technology, Cambridge, Ma. 02139.
The research described in this presentation involves the authorš performance evaluation of four new and alternative remediation technologies, a discussion of several additional innovative technologies in terms of key criteria, and the lead authoršs work synthesizing the considerable literature on arsenic remediation technologies into an open-source database. The promise of and obstacles to the application of new and innovative arsenic remediation technologies will also be discussed. The four new and alternative technologies investigated were 1) iron filings, 2) iron oxide coated sand, 3) & 4) two different systems using modified activated alumina metal oxides. These systems were field tested at a total of eleven different sites in Massachusetts, New Hampshire and Nepal with source water total arsenic concentrations ranging from 100 1,000 ug/l. The iron filings media and the iron oxide coated sand gave treated water total arsenic concentrations respectively of < 5 ug/l 11 ug/l and <10 100 ug/l respectively. The two modified activated alumina metal oxide systems produced treatment water consistently < 5 ug/l or < 10 ug/l. The costs of all these systems make them affordable, comparable to or less than conventional systems. This presentation describes several additional new technologies: granular ferric hydroxide, a ligand-based ceramic technology, biological filtration, new resin developments and nanofiltration and applies the criteria of performance, cost and environmental effects to come up with a preliminary evaluation of the viability of all these alternatives. The last part of the presentation "tours" two Web sites: http://web.mit.edu/murcott/www/arsenic and http://www.thinkcycle.org. The first Web site offers a database of over 50 specific arsenic remediation options. The thinkcycle Web site supports an open-source community engaged in design and engineering challenges and, under the arsenic treatment technology challenge, provides a virtual space in which to freely collect and exchange information on arsenic treatment so that this important public health issue can be swiftly and effectively addressed.