TY - JOUR
T1 - Ranking traditional and nano-enabled sorbents for simultaneous removal of arsenic and chromium from simulated groundwater
AU - Gifford, Mac
AU - Hristovski, Kiril
AU - Westerhoff, Paul
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/12/1
Y1 - 2017/12/1
N2 - Water from many municipal and private wells are treated to meet arsenic (As(V)) regulations, and new regulations for hexavalent chromium (Cr(VI)) are soon possible. Rather than adding costly capital infrastructure, we explored many types of sorbents' ability to remove both oxygenated anions simultaneously. In laboratory pseudo-equilibrium tests, metal (hydr)oxide sorbents demonstrated high affinity for As(V) but exhibited 30 to 100-fold lower capacities to remove Cr(VI). WBAX resins had some ability to sorb both Cr(VI) and As(V), but competing anions lowered their sorption capacity for As(V) by > 90% compared to in a deionized water matrix. Nano-enabled sorbents with iron or titanium nanoparticles embedded inside the porous structure of an anion exchange resin demonstrated high ability to remove both pollutants simultaneously despite competition, with the tested sorbents showing 11 μmol/g capacity for Cr(VI) and 19 μmol/g for As(V) in simulated groundwater on average. To quantitatively rank sorbents' ability to remove multiple pollutants, a Simultaneous Removal Capacity scoring tool is proposed. This index uses both absolute removal capacity for each contaminant and relative capacity for multiple contaminants, and may be applied to simultaneous removal of any set of aqueous or atmospheric contaminants. Here, the five nano-enabled sorbents ranked in the top seven out of twelve sorbents tested for simultaneous Cr(VI) and As(V) removal. This work demonstrated traditional and novel nano-enabled sorbents can reduce multiple contaminants of health concern, resulting in groundwater treated to drinking water standards.
AB - Water from many municipal and private wells are treated to meet arsenic (As(V)) regulations, and new regulations for hexavalent chromium (Cr(VI)) are soon possible. Rather than adding costly capital infrastructure, we explored many types of sorbents' ability to remove both oxygenated anions simultaneously. In laboratory pseudo-equilibrium tests, metal (hydr)oxide sorbents demonstrated high affinity for As(V) but exhibited 30 to 100-fold lower capacities to remove Cr(VI). WBAX resins had some ability to sorb both Cr(VI) and As(V), but competing anions lowered their sorption capacity for As(V) by > 90% compared to in a deionized water matrix. Nano-enabled sorbents with iron or titanium nanoparticles embedded inside the porous structure of an anion exchange resin demonstrated high ability to remove both pollutants simultaneously despite competition, with the tested sorbents showing 11 μmol/g capacity for Cr(VI) and 19 μmol/g for As(V) in simulated groundwater on average. To quantitatively rank sorbents' ability to remove multiple pollutants, a Simultaneous Removal Capacity scoring tool is proposed. This index uses both absolute removal capacity for each contaminant and relative capacity for multiple contaminants, and may be applied to simultaneous removal of any set of aqueous or atmospheric contaminants. Here, the five nano-enabled sorbents ranked in the top seven out of twelve sorbents tested for simultaneous Cr(VI) and As(V) removal. This work demonstrated traditional and novel nano-enabled sorbents can reduce multiple contaminants of health concern, resulting in groundwater treated to drinking water standards.
KW - Arsenic
KW - Hexavalent chromium
KW - Nanocomposite sorbents
KW - Simultaneous removal
KW - Sorption
UR - http://www.scopus.com/inward/record.url?scp=85020193020&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020193020&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2017.05.126
DO - 10.1016/j.scitotenv.2017.05.126
M3 - Article
C2 - 28599363
AN - SCOPUS:85020193020
SN - 0048-9697
VL - 601-602
SP - 1008
EP - 1014
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -