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Chen Y, Qin H, Lu Y, Liu H, Zhang J. A novel method to measure air-immobile regions of the composting pile by inverse calculation combined with gas tracer test. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:131-140. [PMID: 35830767 DOI: 10.1016/j.wasman.2022.06.036] [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: 04/11/2022] [Revised: 06/27/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Air-immobile regions in composting piles obstruct O2 mass transport and exacerbate the formation and emission of harmful off-gases. However, effective methods for measuring the parameters of these air-immobile regions are lacking. With quartz sand piles, this study first adjusted the circumstances of a gas tracer test (gas tracer, its injection volume, and chamber type) using the two-region model (TRM). The effects of β (proportional coefficient of gas in the air-mobile region) and ω (mass exchange coefficient) on the breakthrough curves (BTCs) of the gases were then explored. Finally, an inverse calculation method was used to measure the feature parameters of air-immobile regions in two composting piles (temperature-increasing and thermophilic phases) and estimate the O2 concentrations in different composting piles (50, 100, 200 cm whole height; layers of 50, 100, 200 cm height in a 200-cm high pile). The results showed that the optimal conditions were achieved when 100 mL helium (He) as the gas tracer and a cylinder with a height/diameter ratio of 3 as the chamber were used. With the simulating composting piles, increasing β or ω slowed breakthrough and decreased peak concentration in BTCs of a gas tracer. Tracer-inverse calculation protocol can be used to efficiently estimate the volume ratios of air-immobile regions (φ) and first-order mass transfer coefficient (α), with the values of 39%/46% and 0.001/0.006 min-1 in the composting piles during temperature-increasing /thermophilic phase. The TRM also predicted the O2 concentration in the off-gas or air-mobile/immobile regions of the temperature-increasing-phase composting piles.
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Affiliation(s)
- Yixiao Chen
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China
| | - Haiguang Qin
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China
| | - Yulan Lu
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China
| | - Hongtao Liu
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Jun Zhang
- Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin 541004, China.
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van den Berg L, Toja Ortega S, van Loosdrecht MC, de Kreuk MK. Diffusion of soluble organic substrates in aerobic granular sludge: Effect of molecular weight. WATER RESEARCH X 2022; 16:100148. [PMID: 35814501 PMCID: PMC9263526 DOI: 10.1016/j.wroa.2022.100148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/17/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Aerobic granular sludge (AGS) is an advanced biofilm-based technology for wastewater treatment. Diffusion of substrates into the granules is a key aspect of this technology. Domestic wastewater contains soluble organic substrates of different sizes that could potentially diffuse into the granules. In this study, the relation between the molecular weight of a substrate and its diffusion coefficient within the granule was studied with model substrates (polyethylene glycols (PEGs) with a molecular weight between 62 and 10 000 Da). The diffusion coefficients of the model substrates within granules from a full-scale installation were measured with the 'transient uptake of a non-reactive solute' method. The diffusion coefficients in the granules were not significantly different from the diffusion coefficients in water, at least up to 4000 Da molecular weight. This indicates that these PEGs were not obstructed by the granule matrix. The 10 kDa PEG behaved differently from the lighter PEGs, as it could not penetrate the entire granule. Furthermore, the granule structure was characterized with Environmental Scanning Electron Microscopy (ESEM). The granules displayed an open structure with large macropores and semi-solid regions, which contained microbial cells. The diffusion results suggest that most diffusing molecules were unobstructed in the macropores and barely obstructed in the semi-solid regions. Only the diffusion of the 10 kDa PEG seemed to be hindered by the semi-solid regions, but not by the macropores. Lastly, the apparent molecular weight distribution of domestic wastewater soluble COD was determined with ultrafiltration membranes of 100, 10, and 1 kDa molecular weight cut-off. The influent fractionation revealed that a large part (61-69%) of the influent soluble COD was lighter than 1 kDa. As molecules lighter than 1 kDa diffuse easily, the majority of the influent soluble COD can be considered as diffusible COD. These findings provide new insight into the availability of influent COD for granular sludge.
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Affiliation(s)
- Lenno van den Berg
- Department of Water Management, Delft University of Technology, the Netherlands
| | - Sara Toja Ortega
- Department of Water Management, Delft University of Technology, the Netherlands
| | | | - Merle K. de Kreuk
- Department of Water Management, Delft University of Technology, the Netherlands
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Lv L, Han X, Wu X, Li C. The synthesis of high-aspect-ratio Au microwires with a biomolecule for electrochemical sensing. Chem Commun (Camb) 2020; 56:743-746. [PMID: 31844851 DOI: 10.1039/c9cc06523g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gold (Au) crystalline microwires with an unprecedented diameter of >500 nm and an aspect ratio >400 were synthesized using l-tyrosine as a reducing and capping agent. The Au microwires possessed high conductivity and electrocatalytic activities towards glucose and Hg(ii). Their large diameters and aspect ratios also offered maneuverability, and it was easy to produce Au microelectrodes.
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Affiliation(s)
- Lili Lv
- CAS Key Lab of Bio-based materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
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A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling. SENSORS 2019; 19:s19214747. [PMID: 31683828 PMCID: PMC6864660 DOI: 10.3390/s19214747] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/18/2019] [Accepted: 10/30/2019] [Indexed: 02/07/2023]
Abstract
A novel sensing device for simultaneous dissolved oxygen (DO) and pH monitoring specially designed for biofilm profiling is presented in this work. This device enabled the recording of instantaneous DO and pH dynamic profiles within biofilms, improving the tools available for the study and the characterization of biological systems. The microsensor consisted of two parallel arrays of microelectrodes. Microelectrodes used for DO sensing were bare gold electrodes, while microelectrodes used for pH sensing were platinum-based electrodes modified using electrodeposited iridium oxide. The device was fabricated with a polyimide (Kapton®) film of 127 µm as a substrate for minimizing the damage caused on the biofilm structure during its insertion. The electrodes were covered with a Nafion® layer to increase sensor stability and repeatability and to avoid electrode surface fouling. DO microelectrodes showed a linear response in the range 0–8 mg L−1, a detection limit of 0.05 mg L−1, and a sensitivity of 2.06 nA L mg−1. pH electrodes showed a linear super-Nernstian response (74.2 ± 0.7 mV/pH unit) in a wide pH range (pH 4−9). The multi-analyte sensor array was validated in a flat plate bioreactor where simultaneous and instantaneous pH and DO profiles within a sulfide oxidizing biofilm were recorded. The electrodes spatial resolution, the monitoring sensitivity, and the minimally invasive features exhibited by the proposed microsensor improved biofilm monitoring performance, enabling the quantification of mass transfer resistances and the assessment of biological activity.
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Rivera JF, Sridharan SV, Nolan JK, Miloro SA, Alam MA, Rickus JL, Janes DB. Real-time characterization of uptake kinetics of glioblastoma vs. astrocytes in 2D cell culture using microelectrode array. Analyst 2018; 143:4954-4966. [PMID: 30225487 DOI: 10.1039/c8an01198b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Extracellular measurement of uptake/release kinetics and associated concentration dependencies provides mechanistic insight into the underlying biochemical processes. Due to the recognized importance of preserving the natural diffusion processes within the local microenvironment, measurement approaches which provide uptake rate and local surface concentration of adherent cells in static media are needed. This paper reports a microelectrode array device and a methodology to measure uptake kinetics as a function of cell surface concentration in adherent 2D cell cultures in static fluids. The microelectrode array simultaneously measures local concentrations at five positions near the cell surface in order to map the time-dependent concentration profile which in turn enables determination of surface concentrations and uptake rates, via extrapolation to the cell plane. Hydrogen peroxide uptake by human astrocytes (normal) and glioblastoma multiforme (GBM43, cancer) was quantified for initial concentrations of 20 to 500 μM over time intervals of 4000 s. For both cell types, the overall uptake rate versus surface concentration relationships exhibited non-linear kinetics, well-described by a combination of linear and Michaelis-Menten mechanisms and in agreement with the literature. The GBM43 cells showed a higher uptake rate over the full range of concentrations, primarily due to a larger linear component. Diffusion-reaction models using the non-linear parameters and standard first-order relationships are compared. In comparison to results from typical volumetric measurements, the ability to extract both uptake rate and surface concentration in static media provides kinetic parameters that are better suited for developing reaction-diffusion models to adequately describe behavior in more complex culture/tissue geometries. The results also highlight the need for characterization of the uptake rate over a wider range of cell surface concentrations in order to evaluate the potential therapeutic role of hydrogen peroxide in cancerous cells.
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Affiliation(s)
- Jose F Rivera
- Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
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Chu J, Zhao Y, Li SH, Yu HQ, Liu G, Tian YC. An Integrated Solid-State pH Microelectrode Prepared Using Microfabrication. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2014.11.102] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Liu ZG, Chen X, Liu JH, Huang XJ. Robust electrochemical analysis of As(III) integrating with interference tests: a case study in groundwater. JOURNAL OF HAZARDOUS MATERIALS 2014; 278:66-74. [PMID: 24953937 DOI: 10.1016/j.jhazmat.2014.05.094] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 05/24/2014] [Accepted: 05/31/2014] [Indexed: 06/03/2023]
Abstract
In Togtoh region of Inner Mongolia, northern China, groundwater encountered high concentrations As contamination (greater than 50 μg L(-1)) causes an increasing concern. This work demonstrates an electrochemical protocol for robust (efficient and accurate) determination of As(III) in Togtoh water samples using Au microwire electrode without the need of pretreatment or clean-up steps. Considering the complicated conditions of Togtoh water, the efficiency of Au microwire electrode was systematically evaluated by a series of interference tests, stability and reproducibility measurements. No obvious interference on the determination of As(III) was observed. Especially, the influence of humic acid (HA) was intensively investigated. Electrode stability was also observed with long-term measurements (70 days) in Togtoh water solution and under different temperatures (0-35 °C). Excellent reproducibility (RSD:1.28%) was observed from different batches of Au microwire electrodes. The results obtained at Au microwire electrode were comparable to that obtained by inductively coupled plasma atomic emission spectroscopy (ICP-AES), indicating a good accuracy. These evaluations (efficiency, robustness, and accuracy) demonstrated that the Au microwire electrode was able to determine As(III) in application to real environmental samples.
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Affiliation(s)
- Zhong-Gang Liu
- Nanomaterials and Environmental Detection Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China; Department of Chemistry, University of Science and Technology of China, Hefei 230026, PR China
| | - Xing Chen
- Nanomaterials and Environmental Detection Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China
| | - Jin-Huai Liu
- Nanomaterials and Environmental Detection Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China
| | - Xing-Jiu Huang
- Nanomaterials and Environmental Detection Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, PR China; Department of Chemistry, University of Science and Technology of China, Hefei 230026, PR China.
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Guimerà X, Moya A, Dorado AD, Villa R, Gabriel D, Gabriel G, Gamisans X. Biofilm dynamics characterization using a novel DO-MEA sensor: mass transport and biokinetics. Appl Microbiol Biotechnol 2014; 99:55-66. [DOI: 10.1007/s00253-014-5821-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 05/07/2014] [Indexed: 10/25/2022]
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9
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Kiran R, Rousseau L, Lissorgues G, Scorsone E, Bongrain A, Yvert B, Picaud S, Mailley P, Bergonzo P. Multichannel boron doped nanocrystalline diamond ultramicroelectrode arrays: design, fabrication and characterization. SENSORS 2012; 12:7669-81. [PMID: 22969367 PMCID: PMC3435996 DOI: 10.3390/s120607669] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 05/23/2012] [Accepted: 06/04/2012] [Indexed: 11/16/2022]
Abstract
We report on the fabrication and characterization of an 8 × 8 multichannel Boron Doped Diamond (BDD) ultramicro-electrode array (UMEA). The device combines both the assets of microelectrodes, resulting from conditions in mass transport from the bulk solution toward the electrode, and of BDD's remarkable intrinsic electrochemical properties. The UMEAs were fabricated using an original approach relying on the selective growth of diamond over pre-processed 4 inches silicon substrates. The prepared UMEAs were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results demonstrated that the electrodes have exhibited a very fast electrode transfer rate (k(0)) up to 0.05 cm·s(-1) (in a fast redox couple) and on average, a steady state limiting current (in a 0.5 M potassium chloride aqueous solution containing 1 mM Fe(CN)(6)(4-) ion at 100 mV·s(-1)) of 1.8 nA. The UMEAs are targeted for electrophysiological as well as analytical applications.
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Affiliation(s)
- Raphael Kiran
- CEA-LIST, Diamond Sensors Laboratory, Gif-sur-Yvette 91191, France; E-Mails: (E.S.); (P.B.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-16-908-2756; Fax: +33-16-908-7819
| | - Lionel Rousseau
- Université Paris Est, ESYCOM EA2552, ESIEE Cité Descartes, BP99, Noisy Le Grand 93162, France; E-Mails: (L.R.); (G.L.); (A.B.)
| | - Gaëlle Lissorgues
- Université Paris Est, ESYCOM EA2552, ESIEE Cité Descartes, BP99, Noisy Le Grand 93162, France; E-Mails: (L.R.); (G.L.); (A.B.)
| | - Emmanuel Scorsone
- CEA-LIST, Diamond Sensors Laboratory, Gif-sur-Yvette 91191, France; E-Mails: (E.S.); (P.B.)
| | - Alexandre Bongrain
- Université Paris Est, ESYCOM EA2552, ESIEE Cité Descartes, BP99, Noisy Le Grand 93162, France; E-Mails: (L.R.); (G.L.); (A.B.)
| | - Blaise Yvert
- Institut des Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), Université de Bordeaux, UMR 5287, Bordeaux 33000, France; E-Mail:
| | - Serge Picaud
- INSERM, U968, Institut de la Vision, Paris 75012, France; E-Mail:
- UPMC, Institut de la Vision, Université Paris 06, UMR_S968, Paris 75012, France
| | - Pascal Mailley
- CEA-LITEN-DTS, Laboratoire de Stockage de l'Electricité, Le Bourget du Lac 73377, France; E-Mail:
| | - Philippe Bergonzo
- CEA-LIST, Diamond Sensors Laboratory, Gif-sur-Yvette 91191, France; E-Mails: (E.S.); (P.B.)
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Chen YP, Zhao Y, Chu J, Liu SY, Li WW, Liu G, Tian YC, Xiong Y, Yu HQ. Fabrication and characterization of an innovative integrated solid-state microelectrode. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.05.053] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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