Removal of arsenic from drinking water by iron oxide coated pumice stone

Pratap Gaddy Reddy, University of Texas at El Paso


This research is aimed at a broad audience of rural populations affected by drinking arsenic-contaminated water. Exposure to arsenic in the drinking water has been associated with the development of skin and internal cancers and non-carcinogenic effects such as diabetes, peripheral neuropathy, and cardiovascular disease (Abernathy et al., 593–597). Traditional technologies to remove arsenic from water include: coagulation and filtration, activate alumina, ion-exchange, reverse osmosis, and electro-dialysis. These methods are very expensive to build and operate in rural areas with scattered populations. The focus of this research was to remove the arsenic from drinking water by a sorption process. Batch studies were conducted on twelve adsorbent materials with water containing 100 μg/L arsenic (V). The outcome of the research indicates that iron-oxide-coated pumice stone (IOCPS) removes both arsenic (III) and arsenic (V). The arsenic (V) appears to be more easily removed than arsenic (III). In a laboratory column test, the breakthrough volume of the iron oxide coated pumice stone was 4000 bed volumes. The concentration of arsenic in the feed water was 100 μg/L and the effluent concentration was below detection limit (<2 >μg/L). Optimum empty bed contact time for arsenic (V) removal by the iron oxide coated pumice stone was 8 to 10 minutes. The optimum pH for arsenic removal by IOCPS was found to be in the range of 5.5 to 6.0. The presence of sulfate, chloride, nitrite, nitrate, and phosphate in the water reduces the arsenic removal capacity of iron-oxide-coated pumice stone. Presence of calcium, magnesium in the water does not effect the arsenic removal by iron oxide coated pumice stone. The residual waste is non-hazardous and can be disposed in landfills. ^

Subject Area

Engineering, Civil|Engineering, Sanitary and Municipal|Environmental Sciences|Engineering, Environmental

Recommended Citation

Reddy, Pratap Gaddy, "Removal of arsenic from drinking water by iron oxide coated pumice stone" (2005). ETD Collection for University of Texas, El Paso. AAI3151883.