Next Article in Journal
Association between Psychosocial Working Conditions and Perceived Physical Exertion among Eldercare Workers: A Cross-Sectional Multilevel Analysis of Nursing Homes, Wards and Workers
Previous Article in Journal
A Systematised Review of the Health Impact of Urban Informal Settlements and Implications for Upgrading Interventions in South Africa, a Rapidly Urbanising Middle-Income Country
Previous Article in Special Issue
Turbulent Aggregation and Deposition Mechanism of Respirable Dust Pollutants under Wet Dedusting using a Two-Fluid Model with the Population Balance Method
Open AccessArticle

Effect of Increased Influent COD on Relieving the Toxicity of CeO2 NPs on Aerobic Granular Sludge

1
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China
2
College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Nongda East Road No. 311, Sayibak District, Urumqi 830052, China
*
Author to whom correspondence should be addressed.
Int. J. Environ. Res. Public Health 2019, 16(19), 3609; https://doi.org/10.3390/ijerph16193609
Received: 10 July 2019 / Revised: 15 September 2019 / Accepted: 24 September 2019 / Published: 26 September 2019
(This article belongs to the Special Issue Environmental Behavior of Nanomaterials)
Due to the increased use of cerium oxide nanoparticles (CeO2 NPs), their potential environmental risks have caused concern. However, their effects on the aerobic granular sludge (AGS) process and the later recovery of AGS are still unclear. In this study, we comprehensively determined the changes in pollutant removal and the levels of extracellular polymeric substances (EPS) in AGS that were exposed to CeO2 NP treatments (0 (the control, R0), 1 (R1), and 5 (R5) mg/L), following an increase in the influent chemical oxygen demand (COD). An increase in the CeO2 NP concentration enhanced their inhibitory effect on the removal of total nitrogen (TN) and total phosphorus (TP), and promoted the production of polysaccharides (PS) and proteins (PN) in loosely bound EPS (LB-EPS) or tightly bound EPS (TB-EPS), as well as the dissolved organic carbon (DOC) components in EPS, but had no long-term effects on the removal of organic matter. When the addition of CeO2 NPs was stopped and the concentration of influent COD increased, the TN and TP removal efficiencies in R1 and R5 slowly increased and recovered. In R1, they were only 4.55 ± 0.55% and 2.71 ± 0.58% lower than in R0, respectively, while the corresponding values for R5 were 5.06 ± 0.46% and 6.20 ± 0.63%. Despite the LB-EPS and TB-EPS concentrations in the R1 and R5 treatments recovering and being similar to the levels in the control when no CeO2 NPs were added, they were still slightly higher than in the R0, which indicating that the negative effects of CeO2 NPs could not be completely eliminated due to the residual CeO2 NP levels in AGS. View Full-Text
Keywords: CeO2 nanoparticles; stratified extracellular polymeric substances; aerobic granular sludge; recovery CeO2 nanoparticles; stratified extracellular polymeric substances; aerobic granular sludge; recovery
Show Figures

Figure 1

MDPI and ACS Style

Zheng, X.; Zhang, Y.; Chen, W.; Wang, W.; Xu, H.; Shao, X.; Yang, M.; Xu, Z.; Zhu, L. Effect of Increased Influent COD on Relieving the Toxicity of CeO2 NPs on Aerobic Granular Sludge. Int. J. Environ. Res. Public Health 2019, 16, 3609.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop