2007 Ground Water Summit

Wednesday, May 2, 2007 : 2:00 p.m.

Simple Water Treatment Technologies: Arsenic and Fluoride Removal Using Low-Cost Materials

Thabani B. Mlilo, BSc(Hons)1, Laura Brunson1, Christopher M. Baumert2, Shristi Rajbhandari, MS3 and David A. Sabatini, Ph.D.1, (1)University of Oklahoma, (2)Virginia Polytechnic Institute and State University, (3)Eberhard Karls Universitat Tubingen

The natural occurrence of arsenic and fluoride in drinking water sources is prevalent in many parts of the developing world. Groundwater with concentrations of arsenic and/or fluoride above the World Health Organization’s (WHO) recommended levels of 0.01ppm and 1.5ppm, respectively, poses significant health risks for remote areas. Moreover, with 40% of the world’s population without access to advanced water treatment facilities and with 50% living on less than $2 a day, access to affordable and effective water treatment technologies remains a challenge. This paper evaluates the efficacy and suitability of selected low-cost materials for arsenic and fluoride treatment to the World Health Organization (WHO) stipulated maximum contaminant levels(MCL). The paper presents, discusses and compares the results of batch and column experiments on low-cost media, iron oxide coated sands and bone char, conducted to determine arsenic and fluoride removal rates, adsorption isotherms and breakthrough concentrations with and without competing anions. Preliminary results with iron oxide coated sand (IOCS) indicate significant removal of initial arsenic concentrations (550 ppb) in batch conditions while column tests effectively treated arsenic to below 10ppb for up to 400 pore volumes. Sulfate was found to reduce the arsenic adsorption efficiency in batch tests and reduce the pore volumes required until breakthrough concentrations were reached in the column tests. In contrast, IOCS displayed negligible fluoride removal capacity. Bone char showed effective fluoride removal in batch and column tests. Batch studies display removal efficacy of fluoride concentrations up to 100ppm to below 1.5ppm, with the adsorptive capacity decreasing in the presence of sulfate. In the column studies, breakthrough concentrations at 1.5ppm occurred at 200 pore volumes and decreased to 180 pore volumes in the presence of sulfate concentrations.

Thabani B. Mlilo, BSc(Hons), University of Oklahoma Thabani Mlilo is a graduate student at the University of Oklahoma in Norman. Mlilo has worked in the Oil and Gas industry as part of the Environmental toxicology and Product Safety and Industrial Ecology and Risk Studies groups in the Research and Development division of SASOL, based in South Africa. He has experience in toxicity testing, surface and ground water quality monitoring, ecological and environmental risk assessments, effluent treatment, and public participation forums. He is currently working on his MS under Dr. Sabatini in the Department of Civil Engineering and Environmental Science at the University of Oklahoma.

Laura Brunson, University of Oklahoma Laura Brunson is a GAANN graduate fellow at the University of Oklahoma in Norman. Brunson received a Bachelor of Business in 2002 from the University of Oklahoma. Her experience includes corporate and nonprofit management, sales and marketing positions as well as co-founding Sustainable OKC, a nonprofit organization in Oklahoma City. Her research focuses on the development of sustainable methods for removing arsenic and fluoride from water sources to increase access to potable water in developing areas both locally and globally. She is currently working on her MS under Dr. Sabatini in the Department of Civil Engineering and Environmental Science.

Christopher M. Baumert, Virginia Polytechnic Institute and State University Christopher M. Baumert is a senior civil engineering student at Virginia Polytechnic Institute & State University (Virginia Tech). He has an interest in drinking water for developing countries and public health issues in general. Baumert spent the summer at the University of Oklahoma working with Dr. Sabatini and T. Mlilo, under the Research Experience for Undergraduates (REU) program, on Fluoride treatment technologies.

Shristi Rajbhandari, MS, Eberhard Karls Universitat Tubingen Shristi Rajbhandari is a 2005 MS graduate from the Eberhard Karls Universitat Tubingen in Germany. Rajbhandari completed her MS research on arsenic removal in Dr. Sabatini’s research group at the University of Oklahoma. Originally from Nepal where she completed her undergraduate studies, Shristi currently resides in Kathmandu in Nepal.

David A. Sabatini, Ph.D., University of Oklahoma Dr. Sabatini is David Ross Boyd Professor and Sun Oil Company Chair of Civil Engineering and Environmental Science at the University of Oklahoma, where he has been on the faculty since 1989. His research interests include development of water treatment processes, ground water remediation technologies and environmentally friendly chemical processes and products. He is Director of the OU WaTER (Water Technologies for Emerging Regions) Center. He received his BSCE from the University of Illinois – Urbana, his MSCE from Memphis State University, and his PhD from Iowa State University.


The 2007 Ground Water Summit