Granular media filtration, a widely used process in water and wastewater treatment plants, has the potential for NP abatement. The extensive production and application of engineered silica nanoparticles (SiO2 NPs) will inevitably lead to their release into the environment. This was evident from permeate flux decline of between 30% and 74% at very low TMP (5 kPa) and the further increases in the total resistance. Analyses by batch-dead end filtration revealed the same fouling trend as observed during the continuous MBR experiments membrane fouling is aggravated in the presence of SiO2 NPs. Although the retention of SiO2 NPs in the MBR, as confirmed by dynamic light scattering (DLS) analysis, did not compromise the COD and NH3–N removal, it resulted in substantial increases in the transmembrane pressure (TMP) suggesting the onset of membrane fouling. To investigate these two implications in lab-scale experiments, we continuously operated a control MBR and two experimental MBRs, in which the 28 nm SiO2 NPs and 144 nm SiO2 NPs were added separately to the influent at a final concentration of 100 mg/L. However, for the membrane bioreactor (MBR) system, which is also based on the activated sludge process in addition to the membrane separation process, it has implications not only on the process performance but also on membrane fouling. In conventional activated sludge (CAS) involving aerobic biological processes, the retention of silica nanoparticles (SiO2 NPs) has no detrimental effect on chemical oxygen demand (COD) and ammonia nitrogen (NH3–N) removal. Although some degree of NP adsorption on the biomass was observed using fluorescence microscopy, the affinity of SiO2 NPs for the activated sludge was not enough for a sustained and effective removal of the SiO2 NPs from the wastewater.Ĭopyright © 2015 Elsevier Ltd. The poor removal of the SiO2 NPs was related to the high colloidal stability of the NPs in the wastewater and their limited propensity to biosorption. SiO2 NPs were effectively removed from the wastewater (>96%) during the first 6 days, however the concentration of SiO2 NPs in the effluent gradually increased afterwards and the NP discharge was as high as 65% of the input after 30 days of NP dosing. 7.5 mg L(-1) of fluorescent SiO2 NPs for 30 days. A laboratory-scale activated sludge system consisting of an aeration tank and a settler was fed with synthetic wastewater containing ca. Fluorescent measurements provided an easy and fast method for SiO2 NP tracking. In this work, laboratory-synthesized fluorescent core-shell SiO2 NPs were used to study the fate of these NPs during secondary wastewater treatment. However, the detection of SiO2 NPs in environmental systems is hindered by the elevated background levels of natural silicon. Thus, there is a need to understand the fate of SiO2 NPs during wastewater treatment. Our results provide preliminary validation for the potential use of in clinical medicine and give identifiable ground for the dose selection and bio-nanoagent optimization.Increasing use of silica nanoparticles (SiO2 NPs) in consumer products and industrial processes leads to SiO2 NP discharge into wastewater. Besides the common energy metabolism response to the xenobiotics, also disturbed the metabolic pathways in glycerophospholipid and sphingolipid metabolism, metabolisms of purine, pyrimidine, and nicotinate. And biological tissues (spleen, liver, kidney, and lung) analysis indicated liver and spleen are the targeted-organs of The obvious metabolic variations responding to the biodistribution were induced by although no visible toxic effects were observed in these tissues. Biofluids (plasma and urine) analysis provided the transportation, absorption, and excretion information of Urine metabonome displayed a metabolic recovery while self-regulation of plasma metabonome leaded to the parallel metabolic trends between dosed and control groups in 12 weeks. In this study, the subchronic biological effects and metabolic fate of 20 nm in Sprague–Dawley rats in 12 weeks were investigated by the biochemical assay and NMR-based metabonomic analysis using an intravenous model. However, they have limited clinical applications due to unknown chronic bio-effects and potential bio-related risks. Core–shell structured Fe 3O 2-NH 2 nanoparticles demonstrated outstanding potentials in drug targeting and delivery and medical imaging.
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