An evaluation of the characteristics of membrane materials suitable for the batch fabrication of dissolved oxygen sensors

2003 ◽  
Vol 20 (2) ◽  
pp. 32-40 ◽  
Author(s):  
W.V. Glasspool ◽  
J.K. Atkinson
Keyword(s):  
Dissolved Oxygen ◽  
Cellulose Acetate ◽  
Screen Printing ◽  
Tap Water ◽  
Oxygen Sensors ◽  
Membrane Materials ◽  
Membrane Fabrication ◽  
Batch Fabrication ◽  
Aerosol Spray ◽  
Effects Of Temperature

The bulk batch fabrication process of thick film technology has been utilised in the design and production of miniature amperometric dissolved oxygen sensors based on potentiostatic and voltammetric operation. Three different polymers have been investigated as membrane materials – cellulose acetate, PTFE and PVC. PTFE has been deposited on the devices by aerosol spray and PVC and cellulose acetate by screen‐printing. These methods have been shown to be effective membrane fabrication techniques, and have significant implications in the field of chemical sensors as a whole. All the membrane covered devices investigated were found to exhibit sensitive and linear responses to dissolved oxygen. The effects of temperature and flow rate on sensor response have been investigated and the use of PVC and PTFE in place of cellulose acetate have been shown to reduce both effects. These membranes have also been shown to reduce the detrimental effects of fouling observed on the surfaces of cellulose acetate covered devices as they are powered in tap water.

scholarly journals Temperature Effects on Retention and Separation of PAHs in Reversed-Phase Liquid Chromatography Using Columns Packed with Fully Porous and Core-Shell Particles

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Christophe Waterlot ◽  
Anaïs Goulas
Keyword(s):  
Limit Of Detection ◽  
Tap Water ◽  
Reversed Phase ◽  
Chromatographic Behavior ◽  
Core Shell ◽  
Reversed Phase Liquid Chromatography ◽  
Porous Particles ◽  
Phase Liquid ◽  
Effects Of Temperature ◽  
Shell Particles

Effects of temperature on the reversed-phase chromatographic behavior of PAHs were investigated on three columns. The first was the recent C18column (250 mm × 4.6 mm) packed with 5 µm core-shell particles while the others were more conventional C18columns (250 mm × 4.6 mm) packed with fully porous particles. Among the 16 PAHs studied, special attention has been paid to two pairs of PAHs, fluorene/acenaphthene and chrysene/benzo[a]anthracene, which often present coeluting problems. Due to the low surface area of the core-shell particles, lowest retention time of each PAH was highlighted and effects of the temperature on the separation of PAHs were negligible in regard to those using columns packed with fully porous particles. For each PAH studied, it was demonstrated that peaks were symmetrical and may be considered as Gaussian peaks when the column packed with core-shell particle was employed. In the best condition, the separation of PAHs was conducted at 16°C under very low pressure values (670–950 psi = 46–65 bars). Depending on PAHs, the limit of detection ranged from 0.88 to 9.16 μg L−1. Analysis of spiked acetonitrile samples with PAHs at 10 and 50 µg L−1and tap water at 10 µg L−1gave very good recoveries (94%–109.3%) and high precision (1.1%–3.5%).

The Self-Decay Characteristics of Chlorine Dioxide in Water

2012 ◽  
Vol 610-613 ◽  
pp. 296-299
Author(s):  
Xin Jie Li ◽  
Dan Nan Jiang ◽  
Yue Jun Zhang
Keyword(s):  
Rate Constants ◽  
Tap Water ◽  
Pure Water ◽  
Decay Behaviour ◽  
Increase With Increase ◽  
Higher Temperature ◽  
Effects Of Temperature ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Temperature Water

In order to learn the ClO2 decay behaviour in tap water, the kinetics of ClO2 decay in pure water was studied. Under the conditions of tap water treatment and keeping away from light, the effects of temperature and pH on ClO2 degradation were investigated. The results show that the ClO2 decay reaction in pure water is the first-order with respect to ClO2, the decay rate constants increase with increase in temperature or pH. At pH=6.87, the rate constants are 0.012h-1(15°C), 0.017h-1(25°C), 0.023h-1(35°C), and 0.029h-1(45°C), respectively. At 25°C, the rate constants are 0.0083h-1(pH=4.5), 0.0111h-1(pH=5.5), 0.0143h-1(pH=6.5), 0.0222h-1(pH=7.5), and 0.0351h-1(pH=8.5), respectively. The experimental data prove that ClO2 is more stable in acidic or lower temperature water than in neutral, alkalescent, or higher temperature water.

scholarly journals Review of Dissolved Oxygen Detection Technology: From Laboratory Analysis to Online Intelligent Detection

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3995 ◽  
Author(s):  
Yaoguang Wei ◽  
Yisha Jiao ◽  
Dong An ◽  
Daoliang Li ◽  
Wenshu Li ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Real Time ◽  
Optical Detection ◽  
Oxygen Sensors ◽  
Detection Methods ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Oxygen Detection ◽  
Detection Technology ◽  
Intelligent Technology

Dissolved oxygen is an important index to evaluate water quality, and its concentration is of great significance in industrial production, environmental monitoring, aquaculture, food production, and other fields. As its change is a continuous dynamic process, the dissolved oxygen concentration needs to be accurately measured in real time. In this paper, the principles, main applications, advantages, and disadvantages of iodometric titration, electrochemical detection, and optical detection, which are commonly used dissolved oxygen detection methods, are systematically analyzed and summarized. The detection mechanisms and materials of electrochemical and optical detection methods are examined and reviewed. Because external environmental factors readily cause interferences in dissolved oxygen detection, the traditional detection methods cannot adequately meet the accuracy, real-time, stability, and other measurement requirements; thus, it is urgent to use intelligent methods to make up for these deficiencies. This paper studies the application of intelligent technology in intelligent signal transfer processing, digital signal processing, and the real-time dynamic adaptive compensation and correction of dissolved oxygen sensors. The combined application of optical detection technology, new fluorescence-sensitive materials, and intelligent technology is the focus of future research on dissolved oxygen sensors.

Modeling of UO2 Aqueous Dissolution Over a Wide Range of Conditions

1993 ◽  
Vol 333 ◽  
Author(s):  
Steven A. Steward ◽  
Homer C. Weed
Keyword(s):  
Activation Energy ◽  
Dissolved Oxygen ◽  
Fission Products ◽  
Statistical Experimental Design ◽  
Power Dependence ◽  
Spent Fuel ◽  
Wide Range ◽  
Simulated Groundwater ◽  
Effects Of Temperature ◽  
Half Power

ABSTRACTPreviously it was not possible to predict reliably the rate at which spent fuel would react with groundwater because of conflicting data in the literature. The dissolution of the UO2 spent fuel matrix is a necessary step for aqueous release of radioactive fission products. Statistical experimental design was used to plan a set of UO2 dissolution experiments to examine systematically the effects of temperature (25-75°C), dissolved oxygen (0.002-0.2 atm overpressure), pH (8-10) and carbonate (2-200x10-4 molar) concentrations on UO2 dissolution. The average dissolution rate was 4.3 mg/m2/day. The regression fit of the data indicate an Arrhenius type activation energy of -8750 cal/mol·K and a half-power dependence on dissolved oxygen in the simulated groundwater.

Sign in / Sign up

Export Citation Format

Share Document