TY - JOUR
T1 - Adsorption of arsenic(V) onto single sheet iron oxide
T2 - X-ray absorption fine structure and surface complexation
AU - Yin, Zhou
AU - Lützenkirchen, Johannes
AU - Finck, Nicolas
AU - Celaries, Noémie
AU - Dardenne, Kathy
AU - Hansen, Hans Chr Bruun
PY - 2019/10/15
Y1 - 2019/10/15
N2 - Adsorption onto two-dimensional nanosheet materials offers new possibilities for fast and efficient removal of contaminants from waters. Here, the adsorption of As(V) to a new type of iron oxides – single sheet iron oxide (SSI) – has been studied as a function of time, loading and pH. Adsorption of As(V) onto SSI was very fast compared to other iron oxides, with 80% of total As(V) adsorbed within 10 min. Examination by extended X-ray absorption fine structure analysis showed that As(V) forms a bidentate inner-sphere surface complex with SSI. Arsenic(V) adsorption isotherms and adsorption envelopes were well described using a 1-pK Basic Stern surface complexation model involving protonated ([tbnd]Fe2O2AsO2H−) and unprotonated ([tbnd]Fe2O2AsO2 −2) inner-sphere surface complexes. The surface complexation constants for As(V) binding to SSI is similar to constants found for goethite and ferrihydrite. Simulated adsorption isotherms for intermediate As(V) concentrations also demonstrate that SSI is performing equally well as goethite and ferrihydrite based on surface area normalized adsorption capacities. The binding affinities at micromolar to submicromolar As(V) solution concentrations are similar for SSI and ferrihydrite. SSI has interesting potential as a stable, high-affinity sorbent for use in applications where efficient and fast removal is required.
AB - Adsorption onto two-dimensional nanosheet materials offers new possibilities for fast and efficient removal of contaminants from waters. Here, the adsorption of As(V) to a new type of iron oxides – single sheet iron oxide (SSI) – has been studied as a function of time, loading and pH. Adsorption of As(V) onto SSI was very fast compared to other iron oxides, with 80% of total As(V) adsorbed within 10 min. Examination by extended X-ray absorption fine structure analysis showed that As(V) forms a bidentate inner-sphere surface complex with SSI. Arsenic(V) adsorption isotherms and adsorption envelopes were well described using a 1-pK Basic Stern surface complexation model involving protonated ([tbnd]Fe2O2AsO2H−) and unprotonated ([tbnd]Fe2O2AsO2 −2) inner-sphere surface complexes. The surface complexation constants for As(V) binding to SSI is similar to constants found for goethite and ferrihydrite. Simulated adsorption isotherms for intermediate As(V) concentrations also demonstrate that SSI is performing equally well as goethite and ferrihydrite based on surface area normalized adsorption capacities. The binding affinities at micromolar to submicromolar As(V) solution concentrations are similar for SSI and ferrihydrite. SSI has interesting potential as a stable, high-affinity sorbent for use in applications where efficient and fast removal is required.
KW - Arsenate
KW - Basic stern model
KW - Delamination
KW - Single sheet iron oxide
KW - Surface complexation
UR - http://www.scopus.com/inward/record.url?scp=85068960625&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2019.07.024
DO - 10.1016/j.jcis.2019.07.024
M3 - Journal article
C2 - 31325677
AN - SCOPUS:85068960625
SN - 0021-9797
VL - 554
SP - 433
EP - 443
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -