Removal of arsenic in a sand filter coupled with zero valent iron
Daniel Edward,
Petro Karungamye,
Grite Nelson,
Juma Selemani,
Karoli N. Njau
Affiliations
Daniel Edward
School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania; Corresponding authors at: School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania.
Petro Karungamye
School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania; Department of Chemistry, The University of Dodoma (UDOM), P.O Box 338, Dodoma, Tanzania; Corresponding authors at: School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania.
Grite Nelson
School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania
Juma Selemani
School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania
Karoli N. Njau
School of Materials, Energy, Water, and Environmental Sciences, Nelson Mandela African Institution of Science and Technology, P.O Box 447, Arusha, Tanzania
Arsenic (As) in wastewater has negative effects on the environment and human health, hence As containing wastes must be handled properly. Given the accessibility of metallic iron, studies investigating into the potential application of zerovalent iron in the removal of arsenic are promising. In this study, the performance of sand filter blended with several kinds of zero valent iron (Fe0), such as iron wool, iron fillings, and iron nails, were compared. These materials were combined in a sand filter column, and the efficiency was calculated using the As concentrations in the influent and effluent samples. Experiments were carried out in order to compare performance as a function of Fe0 dose and contact time. The outcome of this investigation showed that sand filter containing iron wool had a better removal efficiency of arsenic removal than iron filings and iron nails. The results in all columns showed that as dosage was increased, removal efficiency of arsenic increased significantly. In case of contact time the results revealed that arsenic can effectively be removed from water in the first 48 h. The early adsorption response is quick in all columns, but get slower as time goes on. The highest removal efficiency was 99.6% and the lowest removal efficiency was 82.7%.
