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Smeraldi J, Tseng LY, Dutta I, Ganesh R, Rosso D. Seasonal occurrence and fate of nanoparticles in two biological wastewater treatment plants in Southern California. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2023; 95:e10858. [PMID: 36973864 DOI: 10.1002/wer.10858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/17/2023] [Accepted: 03/24/2023] [Indexed: 06/18/2023]
Abstract
Nano-sized particles in wastewater are generally considered colloids, but their production and size distribution are not well understood. Organic nano-sized particles are more abundant than engineered nanomaterials in wastewater, where they may cause membrane fouling, harbor pathogens, and transport contaminants to the environment. To our knowledge, this study is the first to examine the seasonal behavior, removal, and the quantity and size of suspended particles (both unfiltered and filtered through a 450 nm filter) at multiple points within different processes along two water resource recovery facilities (WRRFs, formerly wastewater treatment plants). In Southern California where wastewater is often reused or reclaimed, a better understanding of nano-sized particles generation and removal may help reduce cost. We found that both types of the biological secondary treatments investigated (conventional activated sludge process and trickling filter) were more efficient in removing suspended particles larger than 450 nm than they were smaller ones. However, the results show that current treatment processes are not designed to remove nano-sized particles efficiently. We also investigated the factors that correlate with their occurrence and found that there was a significant and direct correlation between influent dissolved chemical oxygen demand (COD) and the abundance of suspended particles both larger and smaller than 450 nm, suggesting that the suspended particles increased with dissolved COD in the WRRFs and thus were biogenically generated during the wastewater treatment. Although no conclusive seasonal correlations were found, dissolved COD management may control nano-sized particle production. PRACTITIONER POINTS: Conventional secondary treatments (activated sludge and trickling filter) could efficiently remove particles but not as efficiently for nano-sized particles (40.1-52.7% removal). At one facility, particles of all sizes were found to correlate with dissolved carbon and EPS, meaning they were biogenic. Monitoring dissolved carbon or EPS precursors may help control membrane fouling post-secondary treatment, and this warrants more studies.
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Affiliation(s)
- Josh Smeraldi
- United States Environmental Protection Agency, New York, New York, USA
| | - Linda Y Tseng
- Environmental Studies Program, Colgate University, Hamilton, New York, USA
- Department of Physics and Astronomy, Colgate University, Hamilton, New York, USA
| | - Ishir Dutta
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | | | - Diego Rosso
- Department of Civil and Environmental Engineering, University of California, Irvine, California, USA
- Water-Energy Nexus Center, University of California, Irvine, California, USA
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2
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Potnis CS, Chauhan R, Kalbfleisch TS, Alexander E, Eichhold L, Bansal M, Grapperhaus CA, Keynton RS, Linder MW, Gupta G. Enhancing the compatibility of BioCaRGOS silica sol-gel technology with ctDNA extraction and droplet digital PCR (ddPCR) analysis. RSC Adv 2022; 12:29399-29404. [PMID: 36320771 PMCID: PMC9557972 DOI: 10.1039/d2ra05862f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022] Open
Abstract
Previously, our group had demonstrated long term stabilization of protein biomarkers using BioCaRGOS, a silica sol-gel technology. Herein, we describe workflow modifications to allow for extraction of cell free DNA (cfDNA) from primary samples containing working concentrations of BioCaRGOS, as well as the compatibility of BioCaRGOS with droplet digital PCR (ddPCR) analysis for pancreatic cancer biomarkers i.e., KRAS circulating tumor DNA (ctDNA). Preliminary attempts to extract ctDNA from BioCaRGOS containing samples demonstrated interference in the extraction of primary samples and the interference with ddPCR analysis when BioCaRGOS was directly introduced to stabilize sample extracts. In our modified technique, we have minimized the interference caused by methanol with ddPCR by complete removal of methanol from the activated BioCaRGOS formulation prior to addition to the biospecimen or ctDNA extract. Interference of the silica matrix present in BioCaRGOS with ctDNA extraction was eliminated through the introduction of invert filtration of the sample prior to extraction. These modifications to the workflow of BioCaRGOS containing samples allow for use of BioCaRGOS for stabilization of trace quantities of nucleic acid biomarkers such as plasma ctDNA, while retaining the capability to extract the biomarker and quantify based on ddPCR.
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Affiliation(s)
- Chinmay S Potnis
- Department of Chemistry, University of Louisville Louisville 40292 Kentucky USA
| | - Rajat Chauhan
- Department of Chemical Engineering, University of Louisville Louisville 40292 Kentucky USA
| | - Theodore S Kalbfleisch
- Department of Chemical Engineering, University of Louisville Louisville 40292 Kentucky USA
| | - Evan Alexander
- Department of Pathology and Laboratory Medicine, University of Louisville Louisville 40292 Kentucky USA
| | - Lindsay Eichhold
- Department of Chemical Engineering, University of Louisville Louisville 40292 Kentucky USA
| | - Meenakshi Bansal
- Department of Chemistry, Thomas More University Crestview Hills KY 41017 USA
| | - Craig A Grapperhaus
- Department of Chemistry, University of Louisville Louisville 40292 Kentucky USA
| | - Robert S Keynton
- William States Lee College of Engineering, University of North Carolina at Charlotte 28223 USA
| | - Mark W Linder
- Department of Pathology and Laboratory Medicine, University of Louisville Louisville 40292 Kentucky USA
| | - Gautam Gupta
- Department of Chemical Engineering, University of Louisville Louisville 40292 Kentucky USA
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Velez-Saboyá CS, Guzmán-Sepúlveda JR, Ruiz-Suárez JC. Phase transitions of liposomes: when light meets heat. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:124002. [PMID: 34936996 DOI: 10.1088/1361-648x/ac45b7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Phase transitions of liposomes are normally studied by differential scanning calorimetry. A suspension of liposomes is subjected to an increase (decrease) of temperature and when heat is absorbed (released), the liposomes transit from a gel (liquid) to a liquid (gel) phase. This endothermic (exothermic) process takes place at a temperature called the melting temperatureTm, which is distinctive of the type of lipids forming the vesicles. The vesicles, though, also modify their size in the transition. Indeed, the thickness of the membranes decreases (increases) because carbon tails misalign (align). Concomitant with the modifications in the membrane thickness, the diameter (D) of the liposomes changes too. Therefore, when they are inspected by light, the scattered signal carries information from such dilatation (contraction) process. We performed careful experiments using dynamic light scattering as a function of temperature to detect the size changes of different liposomes. Gaussian fits of the derivatives of theDvsTcurves coincide within 1% with thermograms, which hints to the possibility of performing thermodynamic studies of lipid systems employing light.
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Affiliation(s)
| | | | - J C Ruiz-Suárez
- CINVESTAV-Monterrey, PIIT, Apodaca, Nuevo León 66600, Mexico
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4
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An Update to Dialysis-Based Drug Release Testing-Data Analysis and Validation Using the Pharma Test Dispersion Releaser. Pharmaceutics 2021; 13:pharmaceutics13122007. [PMID: 34959289 PMCID: PMC8708653 DOI: 10.3390/pharmaceutics13122007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/20/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022] Open
Abstract
Currently, a wide variety of complex non-oral dosage forms are entering the global healthcare market. Although many assays have been described in recent research, harmonized procedures and standards for testing their in vitro performance remain widely unexplored. Among others, dialysis-based techniques such as the Pharma Test Dispersion Releaser are developed for testing the release of drugs from nanoparticles, liposomes, or extracellular vesicle preparations. Here, we provide advanced strategies and practical advice for the development and validation of dialysis-based techniques, including documentation, analysis, and interpretation of the raw data. For this purpose, key parameters of the release assay, including the hydrodynamics in the device at different stirring rates, the selectivity for particles and molecules, as well as the effect of excipients on drug permeation were investigated. At the highest stirring rate, a more than twofold increase in the membrane permeation rate (from 0.99 × 10−3 to 2.17 × 10−3 cm2/h) was observed. Additionally, we designed a novel computer model to identify important quality parameters of the dialysis experiment and to calculate error-corrected release profiles. Two hydrophilic creams of diclofenac, Voltaren® Emulgel, and Olfen® gel, were tested and provide first-hand evidence of the robustness of the assay in the presence of semisolid dosage forms.
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Hawes GF, Punckt C, Pope MA. Probing Sulfur Deposition onto Carbon Nanomaterials from Aqueous, Elemental Sulfur Sols for Lithium-Sulfur Batteries. ACS APPLIED MATERIALS & INTERFACES 2021; 13:31569-31582. [PMID: 34196526 DOI: 10.1021/acsami.1c04484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Sulfur cathodes for lithium-sulfur batteries often rely on integrating sulfur with high surface area carbonaceous materials. Nanoscale mixing is typically achieved by a lengthy, high-temperature melt imbibition approach that employs carbon nanomaterials in an aggregated solid form. In this work, we present a simple strategy to coat carbon nanomaterials with sulfur in a cost-effective, room-temperature process using inexpensive elemental sulfur. Our results are based on hydrophobic sulfur sols, which have rarely been examined for use in the preparation of sulfur cathodes. We study the deposition mechanism on different carbon materials and find that sulfur dissolves from the sol into the aqueous phase and coats the surface of reduced graphene oxide (rGO) by heterogeneous nucleation and growth, but that this mechanism is not favored for carbon materials such as Ketjen black (KB) and graphene oxide (GO), for which undesirable homogeneous nucleation of micron-sized, insulating sulfur crystals is observed. High loading (3-4 mgsulfur/cm2) rGO-based cathodes prepared using this approach achieve discharge capacities of 1300 mAh/gsulfur (∼4.8 mAh/cm2) at 0.1C and achieve capacities 7-fold higher than cells prepared via traditional melt imbibition approaches at higher rates of 0.8C and 1C. Cells prepared without the need for added binder or conductive additive achieve projected full cell energy densities of 468 Wh/kg at 0.1C when taking into account all inactive components and assuming no lithium metal degradation, indicating that the deposition of sulfur from hydrophobic sols onto carbon nanomaterials can serve as a simple, aqueous-based, one-step process to prepare high sulfur loading cathodes with high projected energy densities.
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Affiliation(s)
- Gillian F Hawes
- Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo N2L 3G1, Ontario, Canada
| | - Christian Punckt
- Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU), Helmholtzstr. 11, Ulm D-89081, Germany
| | - Michael A Pope
- Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo N2L 3G1, Ontario, Canada
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Wusigale, Wang T, Hu Q, Xue J, Khan MA, Liang L, Luo Y. Partition and stability of folic acid and caffeic acid in hollow zein particles coated with chitosan. Int J Biol Macromol 2021; 183:2282-2292. [PMID: 34102238 DOI: 10.1016/j.ijbiomac.2021.05.216] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/21/2021] [Accepted: 05/31/2021] [Indexed: 12/13/2022]
Abstract
The carriers for hydrophobic bioactives have been extensively studied, while those for hydrophilic bioactives are still challenging. The partition of bioactives in the particles depends greatly on their solubility, interaction with carrier materials, as well as structure of carriers. In this study, chitosan-coated hollow zein particles using calcium phosphate as a sacrificing template (CS-HZ) were fabricated to co-encapsulate folic acid (FA) and caffeic acid (CA). Partition, photostability, and antioxidant capacity of bioactive compounds were also studied. The size, polydispersity index and ζ-potential of optimized CS-HZ were 176.3 nm, 0.14 and +39.3 mV, respectively, indicating their small and uniform dimension with excellent colloidal stability. FA interacted with chitosan to form complexes and then coated on the zein particles where CA was encapsulated. After co-encapsulation in CS-HZ, the photostability of both FA and CA was improved in comparison with encapsulation of single compound, with 85% of FA remaining after 240 min of UVA irradiation, and 90% of CA remaining after 80 min. Antioxidant activity of CA decreased upon encapsulation, but significantly increased after irradiation. Findings in this study shed some light on the design of carriers for co-delivery of hydrophilic compounds in acidic condition.
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Affiliation(s)
- Wusigale
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA
| | - Taoran Wang
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA
| | - Qiaobin Hu
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA
| | - Jingyi Xue
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA
| | - Muhammad Aslam Khan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China
| | - Li Liang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China.
| | - Yangchao Luo
- Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA.
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Feroz H, Bai M, Kwon H, Brezovec J, Peng J, Kumar M. Can Fibrous Mats Outperform Current Ultrafiltration and Microfiltration Membranes? Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.7b01351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hasin Feroz
- Department
of Chemical Engineering, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Michelle Bai
- Departments
of Chemical Engineering and Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - HyeYoung Kwon
- Department
of Chemical Engineering, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - John Brezovec
- Department
of Chemical Engineering, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
| | - Jing Peng
- Department
of Environmental Systems Engineering, The Pennsylvania State University, University Park 16801, Pennsylvania, United States
| | - Manish Kumar
- Department
of Chemical Engineering, The Pennsylvania State University, University
Park, Pennsylvania 16802, United States
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8
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Schmitz D, Pich A. Responsive microgels with supramolecular crosslinks: synthesis and triggered degradation in aqueous medium. Polym Chem 2016. [DOI: 10.1039/c6py01039c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stimuli-responsive microgels containing supramolecular crosslinks based on cholesteryl/β-cyclodextrin interactions were synthesized and degraded upon addition of 1-adamantanecarboxylic acid.
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Affiliation(s)
- D. Schmitz
- Functional and Interactive Polymers
- Institute of Technical and Macromolecular Chemistry
- RWTH Aachen University
- Aachen
- Germany
| | - A. Pich
- Functional and Interactive Polymers
- Institute of Technical and Macromolecular Chemistry
- RWTH Aachen University
- Aachen
- Germany
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Weil M, Meißner T, Busch W, Springer A, Kühnel D, Schulz R, Duis K. The oxidized state of the nanocomposite Carbo-Iron® causes no adverse effects on growth, survival and differential gene expression in zebrafish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 530-531:198-208. [PMID: 26042533 DOI: 10.1016/j.scitotenv.2015.05.087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/20/2015] [Accepted: 05/20/2015] [Indexed: 05/24/2023]
Abstract
For degradation of halogenated chemicals in groundwater Carbo-Iron®, a composite of activated carbon and nano-sized Fe(0), was developed (Mackenzie et al., 2012). Potential effects of this nanocomposite on fish were assessed. Beyond the contaminated zone Fe(0) can be expected to have oxidized and Carbo-Iron was used in its oxidized form in ecotoxicological tests. Potential effects of Carbo Iron in zebrafish (Danio rerio) were investigated using a 48 h embryo toxicity test under static conditions, a 96 h acute test with adult fish under semi-static conditions and a 34 d fish early life stage test (FELST) in a flow-through system. Particle diameters in test suspensions were determined via dynamic light scattering (DLS) and ranged from 266 to 497 nm. Particle concentrations were measured weekly in samples from the FELST using a method based on the count rate in DLS. Additionally, uptake of particles into test organisms was investigated using microscopic methods. Furthermore, effects of Carbo-Iron on gene expression were investigated by microarray analysis in zebrafish embryos. In all tests performed, no significant lethal effects were observed. Furthermore, Carbo-Iron had no significant influence on weight and length of fish as determined in the FELST. In the embryo test and the early life stage test, growth of fungi on the chorion was observed at Carbo-Iron concentrations between 6.3 and 25mg/L. Fungal growth did not affect survival, hatching success and growth. In the embryo test, no passage of Carbo-Iron particles into the perivitelline space or the embryo was observed. In juvenile and adult fish, Carbo-Iron was detected in the gut at the end of exposure. In juvenile fish exposed to Carbo-Iron for 29 d and subsequently kept for 5d in control water, Carbo-Iron was no longer detectable in the gut. Global gene expression in zebrafish embryos was not significantly influenced by Carbo-Iron.
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Affiliation(s)
- Mirco Weil
- ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim, Germany.
| | - Tobias Meißner
- Fraunhofer Institute for Ceramic Technologies and Systems, Winterbergstrasse 28, 01277 Dresden, Germany.
| | - Wibke Busch
- Helmholtz Centre for Environmental Research - UFZ, Dept. of Bioanalytical Ecotoxicology, Permoser Strasse 15, 04318 Leipzig, Germany.
| | - Armin Springer
- Centre for Translational Bone, Joint and Soft Tissue Research, Technical University Dresden, Fetscherstrasse 74, 01307 Dresden, Germany.
| | - Dana Kühnel
- Helmholtz Centre for Environmental Research - UFZ, Dept. of Bioanalytical Ecotoxicology, Permoser Strasse 15, 04318 Leipzig, Germany.
| | - Ralf Schulz
- Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, 76829 Landau, Germany.
| | - Karen Duis
- ECT Oekotoxikologie GmbH, Böttgerstrasse 2-14, 65439 Flörsheim, Germany.
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Shang J, Gao X. Nanoparticle counting: towards accurate determination of the molar concentration. Chem Soc Rev 2014; 43:7267-78. [PMID: 25099190 DOI: 10.1039/c4cs00128a] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Innovations in nanotechnology have brought tremendous opportunities for the advancement of many research frontiers, ranging from electronics, photonics, energy, to medicine. To maximize the benefits of nano-scaled materials in different devices and systems, precise control of their concentration is a prerequisite. While concentrations of nanoparticles have been provided in other forms (e.g., mass), accurate determination of molar concentration, arguably the most useful one for chemical reactions and applications, has been a major challenge (especially for nanoparticles smaller than 30 nm). Towards this significant yet chronic problem, a variety of strategies are currently under development. Most of these strategies are applicable to a specialized group of nanoparticles due to their restrictions on the composition and size range of nanoparticles. As research and uses of nanomaterials are being explored in an unprecedented speed, it is necessary to develop universal strategies that are easy to use and are compatible with nanoparticles of different sizes, compositions, and shapes. This review outlines the theories and applications of current strategies to measure nanoparticle molar concentration, discusses the advantages and limitations of these methods, and provides insights into future directions.
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Affiliation(s)
- Jing Shang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA.
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Cottrell BA, Timko SA, Devera L, Robinson AK, Gonsior M, Vizenor AE, Simpson AJ, Cooper WJ. Photochemistry of excited-state species in natural waters: a role for particulate organic matter. WATER RESEARCH 2013; 47:5189-5199. [PMID: 23863383 DOI: 10.1016/j.watres.2013.05.059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/28/2013] [Accepted: 05/31/2013] [Indexed: 06/02/2023]
Abstract
Laser flash photolysis (LFP) was used to characterize a triplet excited state species isolated from Black River and San Joaquin wetlands particulate organic matter (POM). The solubilized organic matter, isolated from POM by pH-independent diffusion in distilled water, was named PdOM. UV-visible absorption spectroscopy, excitation-emission matrix spectroscopy (EEMs), and (1)H NMR were used to characterize the PdOM. While LFP of dissolved organic matter (DOM) is known to generate the solvated electron, LFP of the PdOM transient in argon-, air-, and nitrous oxide-saturated solutions indicated that this was a triplet excited state species ((3)PdOM*). The lifetime and the reactivity of (3)PdOM* with sorbic acid, a triplet state quencher, were compared with that of the triplet excited state of benzophenone, a DOM proxy. A second excited state species (designated DOM*), with a longer lifetime, was reported in a number of previous studies but not characterized. The lifetime of DOM*, measured for seventeen organic matter isolates, lignin, tannic acid, and three wetlands plant extracts, was shown to differentiate allochthonous from autochthonous DOM. (3)POM* and DOM* were also observed in lake water and a constructed wetlands' water. Aqueous extracts of fresh and aged plant material from the same wetland were shown to be one source of these excited state species. This study provides evidence of a role for POM in the photochemistry of natural and constructed wetland waters.
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Affiliation(s)
- Barbara A Cottrell
- Department of Chemistry, University of Toronto Scarborough, Scarborough, ON M1C1A4, Canada.
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Yang Y, Nakada N, Nakajima R, Yasojima M, Wang C, Tanaka H. pH, ionic strength and dissolved organic matter alter aggregation of fullerene C60 nanoparticles suspensions in wastewater. JOURNAL OF HAZARDOUS MATERIALS 2013. [PMID: 23177247 DOI: 10.1016/j.jhazmat.2012.10.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The rapid increase in the production and use of fullerene C(60) nanoparticles raise concerns about environmental risks and human health. Wastewater treatment plants are key barriers to their discharge into the environment. The aggregation behavior of aqueous suspensions of C(60) nanoparticles (nC(60)) could affect their transport, bioavailability, and removal during wastewater treatment. We tested the aggregation of nC(60) in wastewater at different values of pH, ionic strength, and dissolved organic matter (DOM). The nC(60) remained relatively stable in filtered wastewater under environmentally relevant conditions up to 24 h. But at pH 3 or at high ionic strength (>100 mM NaCl), the aggregate size increased greatly, reaching micrometer scale after only 1 h. However, the aggregation behavior varied among wastewater samples even at values of similar zeta potential, compared with that in filtered secondary effluent and aeration tank liquor, that in filtered primary effluent was obviously inhibited. This inhibition could be attributed to the steric stabilization due to the adsorption of DOM on nC(60) aggregate in addition to electrostatic stabilization. The aggregation results also suggest that membrane filtration could be improved by adjustments to pH.
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Affiliation(s)
- Yongkui Yang
- Research Center for Environmental Quality Management, Kyoto University, 1-2 Yumihama, Otsu, Shiga 520-0811, Japan
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