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Crop and Soil Sciences Calendar

Soil Science Seminar

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November 14, 2018 @ 3:40 pm - 5:00 pm

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Soil Science Seminar on Wednesday, 14 November, 2018 will be presented by Maia Fitzstevens, Soil Science MSc Student, Crop & Soil Science Department, NCSU.

Title: “Fluoride and Arsenic Removal by Bone Char in High pH Groundwaters

Pre-seminar refreshments are served at 3:15 pm in the McKimmon Room (2223 WMS). Seminar begins at 3:40 pm in Williams Hall Auditorium (2215 WMS). Everyone is welcome to attend.

Abstract

Arsenic (As) and fluoride (F), both toxic to human health when ingested, are often found as co-contaminants in groundwater at a global scale. These contaminants can threaten human health, especially in rural areas of developing countries, where access to water treatment technology is limited. Previous studies have quantified the uptake of F and As by bone char, a low-cost and widely available material, at circumneutral pH. However, in Latin America, where groundwater co-contamination of As and F is prevalent, groundwater tends to have alkaline pH, and the geochemical behavior of As and F in basic aqueous conditions, as well as their interactions with sorbents such as bone char, can be distinct from neutral or acidic environments. This study evaluates bone char for the removal of F and As at pH 8 and 10 (above the point of zero charge of bone char), and quantifies the effects of competing anions (phosphate and silicate) typically found in Mexican groundwater on the removal capacity of bone char for F and As. Adsorption isotherms for As and F at pH 8 and 10 show that F and As are both taken up by bone char individually, with less removal occurring at pH 10 than pH 8. Adsorption isotherms for fluoride with arsenic present and vice versa at pH 8 and 10 show that the presence of F reduces As uptake, especially at pH 10. Results from competition series experiments (to determine the effects of phosphate and silicate on F and As uptake) show uptake of phosphate and silicate by bone char, and that both are inhibiting As uptake, whereas F uptake is only slightly inhibited. The implications of these results for the use of bone char as a low-cost technology for water treatment in Latin America where groundwater is co-contaminated with As and F will be discussed.

Details


Date
November 14, 2018
Time
3:40 pm - 5:00 pm
Event Category:
Event Tags
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Location
2215 Williams Hall Auditorium
101 Derieux Place
Raleigh, 27695 United States

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