T281 Arsenic, Manganese, Chromium, and Other Geogenic Contaminants, Including Radionuclides in Hydrological Systems—Source, Biogeochemical Cycling, Toxicity, and Removal II

Wednesday, 7 November 2018
1:30 PM - 5:30 PM
Room 133

ARSENITE REMOVAL IN GROUNDWATER TREATMENT PLANTS BY SEQUENTIAL PERMANGANATE―FERRIC TREATMENT

Paper number: T281-6
Program: Technical Sessions
Time: 2:40 PM – 2:55 PM

Authors

Abstract

The Dutch drinking water sector is actively investigating methods to reduce arsenic (As) to <1 µg/L in drinking water supply. We investigated (1) the effectiveness of sequential permanganate (MnO4)—ferric (Fe(III)) dosing during aeration—rapid sand filtration to achieve <1 µg/L As (2) the influence of MnO4—Fe(III) dosing on pre-established removal patterns of As(III), Fe(II), Mn(II) and NH4+ in rapid sand filters and (3) the influence of MnO4—Fe(III) dosing on the settling and molecular-scale structural properties of the filter backwash solids. We report that MnO4—Fe(III) dosing is an effective technique to improve arsenite [As(III)] removal at groundwater treatment plants. At a typical aeration—rapid sand filtration facility in the Netherlands effluent As concentrations of <1 µg/L were achieved with 1.2 mg/L MnO4 and 1.8 mg/L Fe(III). The optimized combination of MnO4 and Fe(III) doses did not affect the removal efficiency of Fe(II), Mn(II) and NH4+ in rapid sand filters, however, the removal patterns of Fe(II) and Mn(II) in rapid sand filter were altered, as well as the settling behaviour of backwash solids. The characterization of backwash solids by Fe K-edge X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) showed that the altered settling behaviour of backwash solids was not due to changes in the molecular-scale structure of Fe-precipitates that formed during treatment.

Key words

Arsenic removal; Arsenite oxidation; Drinking water; Groundwater treatment; Permanganate; Rapid sand filtration

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-320306

© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.