Chapter 28
Downloaded by UNIV ILLINOIS URBANA on October 29, 2013 | http://pubs.acs.org Publication Date: October 3, 2005 | doi: 10.1021/bk-2005-0915.ch028
Two-Year Operation of an Air-Iron Treatment System for the Removal of Arsenic from Simulated Bangladeshi Tubewell Water Ahmedul Hye Chowdhury and Phillip T. Crisp School of Chemical Engineering and Indutrial Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
A model system for As(III) removal from simulated Bangladeshi tubewell water (in mg/L: As(III) 0.2, Fe(II) 5, Ca 40, Na 50, S0 9, Cl 70, H C O 133, P0 6, SiO 20) was operated indoors for a period of 2 years at the rate of 8 L per day. The system comprised: 1. water storage tank with tap regulator, 2. tank with internal baffles which forced water repeatedly down through crushed brick and up to the surface, 3. tank containing scrap iron (fire-burnt tin-plated steel cans), 4. water lock to maintain water level, and 5. storage tank. In tank 2, particles of Fe(OH) .nH O (I) were retained in the crushed brick, while As was partially precipitated with I and partially oxidized to As(V). Arsenic removal in tank 2 varied from 95% to 30% (in the presence of PO & SiO ). The arsenic concentration in the output water was
