Arsenic treatment considerations

The best arsenic treatment technique for a given utility will depend on ars enic concentration and species in source water, other constituents in the w ater, existing treatment processes, treatment costs, and handling of residu als. To evaluate these issues a national survey investigated arsenic occurr ence and speciation in US drinking, water sources. in general, total arseni c concentration was higher in groundwater than in surface water supplies. P articulate arsenic was more abundant than previously and more arsenate than arsenite was present. The cost arsenic: treatment increased in the followi ng order: modified conventional treatment << activated alumina or anion exc hange < reverse osmosis. Nevertheless, the most cost-effective treatment mi ght not be best, because secondary treatment benefits and residuals handlin g should also be taken into account.