TY - JOUR
T1 - Simultaneous removal of nanosilver and fullerene in sequencing batch reactors for biological wastewater treatment
AU - Yang, Yu
AU - Wang, Yifei
AU - Hristovski, Kiril
AU - Westerhoff, Paul
N1 - Funding Information:
This study was partially funded by the Water Environment Research Foundation (RD831713) and National Science Foundation (CBET 0847710). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the WERF or NSF.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Increasing use of engineered nanomaterials (ENMs) inevitably leads to their potential release to the sewer system. The co-removal of nano fullerenes (nC60) and nanosilver as well as their impact on COD removal were studied in biological sequencing batch reactors (SBR) for a year. When dosing nC60 at 0.07-2mgL-1, the SBR removed greater than 95% of nC60 except for short-term interruptions occurred (i.e., dysfunction of bioreactor by nanosilver addition) when nC60 and nanosilver were dosed simultaneously. During repeated 30-d periods of adding both 2mgL-1 nC60 and 2mgL-1 nanosilver, short-term interruption of SBRs for 4d was observed and accompanied by (1) reduced total suspended solids in the reactor, (2) poor COD removal rate as low as 22%, and (3) decreased nC60 removal to 0%. After the short-term interruption, COD removal gradually returned to normal within one solids retention time. Except for during these "short-term interruptions", the silver removal rate was above 90%. A series of bottle-point batch experiments was conducted to determine the distribution coefficients of nC60 between liquid and biomass phases. A linear distribution model on nC60 combined with a mass balance equation simulated well its removal rate at a range of 0.07-0.76mgL-1 in SBRs. This paper illustrates the effect of "pulse" inputs (i.e., addition for a short period of time) of ENMs into biological reactors, demonstrates long-term capability of SBRs to remove ENMs and COD, and provides an example to predict the removal of ENMs in SBRs upon batch experiments.
AB - Increasing use of engineered nanomaterials (ENMs) inevitably leads to their potential release to the sewer system. The co-removal of nano fullerenes (nC60) and nanosilver as well as their impact on COD removal were studied in biological sequencing batch reactors (SBR) for a year. When dosing nC60 at 0.07-2mgL-1, the SBR removed greater than 95% of nC60 except for short-term interruptions occurred (i.e., dysfunction of bioreactor by nanosilver addition) when nC60 and nanosilver were dosed simultaneously. During repeated 30-d periods of adding both 2mgL-1 nC60 and 2mgL-1 nanosilver, short-term interruption of SBRs for 4d was observed and accompanied by (1) reduced total suspended solids in the reactor, (2) poor COD removal rate as low as 22%, and (3) decreased nC60 removal to 0%. After the short-term interruption, COD removal gradually returned to normal within one solids retention time. Except for during these "short-term interruptions", the silver removal rate was above 90%. A series of bottle-point batch experiments was conducted to determine the distribution coefficients of nC60 between liquid and biomass phases. A linear distribution model on nC60 combined with a mass balance equation simulated well its removal rate at a range of 0.07-0.76mgL-1 in SBRs. This paper illustrates the effect of "pulse" inputs (i.e., addition for a short period of time) of ENMs into biological reactors, demonstrates long-term capability of SBRs to remove ENMs and COD, and provides an example to predict the removal of ENMs in SBRs upon batch experiments.
KW - Nano fullerene
KW - Nanosilver
KW - SBR
KW - Waste water treatment
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U2 - 10.1016/j.chemosphere.2014.12.003
DO - 10.1016/j.chemosphere.2014.12.003
M3 - Article
C2 - 25532763
AN - SCOPUS:84923568552
VL - 125
SP - 115
EP - 121
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
ER -