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| Impact of ZnO nanoparticles on the activity of the activated sludge in SBR |
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Abstract The impact of ZnO nanoparticles (ZnO-NPs) on the activity of activated sludge in SBR was investigated. Results indicated that no significantly adverse effects were discovered of ZnO-NPs in the activity of activated sludge at low exposure concentration (10mg/L). Adversely, significant effects were observed on the activities of the sludge such as sedimentation, yield and constituents of extracellular polymeric substances (EPS) and soluble microorganism products (SMP) as well as degradation efficiency of organics when ZnO-NPs was exposed to the activated sludge system at higher concentration (20,50,100mg/L). Namely, COD removal decreased by 8.1%, 19.5% and 27.7%, respectively, the sedimentation efficiency of sludge decreased by 24.2%, 35.0% and 36.0%, MLVSS/MLSS ratio decreased by 8.0%, 14.7% and 21.0%, the respiratory rate was inhibited by 54.0%, 79.0% and 80.3%; the yield of EPS decreased by 29.0%, 49.9% and 65.4% and the yield of SMP increased by 48.9%, 102.6% and 203.0%. The results demonstrated that ZnO-NPs could inhibit the activity of activated sludge by suppressing the metabolism and yield of sludge.
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Received: 21 January 2014
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