title: Removal of arsenic from water using Fe-exchanged natural zeolite.
abstract: An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using iron/aluminum hydroxide to remove As from water is a proven technology. However, separation of As-bearing fine particles from treated water presented a challenge. An alternative method was to use coarse-grained sorbents to increase the flow rate and throughput. In this research, a natural zeolite (clinoptilolite) was exchanged with iron(III) to enhance its As removal. Batch test results showed a Fe(III) sorption capacity of 144 mmol/kg on the zeolite. The As sorption on the Fe-exchanged zeolite (Fe-eZ) could reach up to 100mg/kg. Columns packed with Fe-eZ were tested for As removal from water collected from acid mine drainage (AMD) and groundwater containing high natural organic matter and high As(III). With an initial concentration of 147 μg/L in the AMD water, a complete As removal was achieved up to 40 pore volumes. However, the Fe-eZ was not effective to remove As from Chia-Nan Plain groundwater due to its high initial As concentration (511 μg/L), high amounts of natural organic matter, as well as its low oxidation-reduction potential, under which the As was in reduced As(III) form.
authors.affiliation: Geosciences Department, University of Wisconsin - Parkside, Kenosha, WI 53144, USA. li@uwp.edu
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Li
authors.forename: Jiin-Shuh
authors.initials: JS
authors.lastname: Jean
authors.forename: Wei-Teh
authors.initials: WT
authors.lastname: Jiang
authors.forename: Po-Hsiang
authors.initials: PH
authors.lastname: Chang
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Chen
authors.forename: Libing
authors.initials: L
authors.lastname: Liao
mesh_terms: D001151:Arsenic / Q000302:isolation & purification*; D007501:Iron / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D017641:Zeolites; D007501:Iron; D001151:Arsenic