TY - JOUR
T1 - Elemental copper nanoparticle toxicity to anaerobic ammonium oxidation and the influence of ethylene diamine-tetra acetic acid (EDTA) on copper toxicity
AU - Gonzalez-Estrella, Jorge
AU - Li, Guangbin
AU - Neely, Sarah E.
AU - Puyol, Daniel
AU - Sierra-Alvarez, Reyes
AU - Field, Jim A.
N1 - Funding Information:
This work was supported by the Semiconductor Research Corporation (SRC)/Sematech Engineering Research Center for Environmentally Benign Semiconductor Manufacturing (426.036). This work was partly funded the National Institute of Environmental Health Sciences-supported Superfund Research Program (NIH ES-04940) and by the National Science Foundation (NSF CBET-1234211). Gonzalez-Estrella was also funded by CONACyT (308577).
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017
Y1 - 2017
N2 - Soluble ions released by elemental copper nanoparticles (Cu0 NP) are toxic to key microorganisms of wastewater treatment processes. However, their toxicity to anaerobic ammonium oxidation (anammox) has not yet been studied. Chelating agents occurring in wastewater may decrease copper ions (Cu2+) concentration and consequently, decrease copper toxicity. This study evaluated Cu0 NP and CuCl2 toxicity to anammox and the influence of ethylene diamine-tetra acetic acid (EDTA) on copper toxicity. Bioassays were supplemented with Cu0 NP or CuCl2 with and without EDTA. Anammox activities were used to calculate inhibition constants (Ki). Results showed that Cu0 NP are toxic to anammox. Ki constants with respect to added copper were 1.8- and 2.81-fold larger (less toxic) in EDTA-containing assays for Cu0 NP and CuCl2, respectively, compared to EDTA-free assays. Additionally, Ki constants calculated in EDTA-free assays with respect the measured dissolved copper concentration were 0.023 mM Cu0 NP and 0.014 mM CuCl2. The similarity of these Ki constants indicates that Cu0 NP toxicity to anammox is caused by the release of Cu2+. Finally, severe toxicity caused by 0.315 mM and Cu0 NP 0.118 mM CuCl2 was attenuated by 88–100% when 0.14 mM EDTA was supplied. Toxicity attenuation likely occurred because EDTA complexed Cu2+ ions, thus, decreasing their bioavailability. Overall, this study indicates that Cu0 NP and CuCl2 are toxic to anammox, and furthermore, that EDTA attenuates Cu0 NP and CuCl2 toxicity to anammox by complexing Cu2+ ions.
AB - Soluble ions released by elemental copper nanoparticles (Cu0 NP) are toxic to key microorganisms of wastewater treatment processes. However, their toxicity to anaerobic ammonium oxidation (anammox) has not yet been studied. Chelating agents occurring in wastewater may decrease copper ions (Cu2+) concentration and consequently, decrease copper toxicity. This study evaluated Cu0 NP and CuCl2 toxicity to anammox and the influence of ethylene diamine-tetra acetic acid (EDTA) on copper toxicity. Bioassays were supplemented with Cu0 NP or CuCl2 with and without EDTA. Anammox activities were used to calculate inhibition constants (Ki). Results showed that Cu0 NP are toxic to anammox. Ki constants with respect to added copper were 1.8- and 2.81-fold larger (less toxic) in EDTA-containing assays for Cu0 NP and CuCl2, respectively, compared to EDTA-free assays. Additionally, Ki constants calculated in EDTA-free assays with respect the measured dissolved copper concentration were 0.023 mM Cu0 NP and 0.014 mM CuCl2. The similarity of these Ki constants indicates that Cu0 NP toxicity to anammox is caused by the release of Cu2+. Finally, severe toxicity caused by 0.315 mM and Cu0 NP 0.118 mM CuCl2 was attenuated by 88–100% when 0.14 mM EDTA was supplied. Toxicity attenuation likely occurred because EDTA complexed Cu2+ ions, thus, decreasing their bioavailability. Overall, this study indicates that Cu0 NP and CuCl2 are toxic to anammox, and furthermore, that EDTA attenuates Cu0 NP and CuCl2 toxicity to anammox by complexing Cu2+ ions.
KW - Anammox
KW - Complexation
KW - Inhibition constant
KW - Nanomaterials
KW - Nitrogen removal
KW - Toxicity attenuation
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U2 - 10.1016/j.chemosphere.2017.06.054
DO - 10.1016/j.chemosphere.2017.06.054
M3 - Article
C2 - 28641224
AN - SCOPUS:85020942311
VL - 184
SP - 730
EP - 737
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
ER -