scholarly journals Biomorphic microchanneled electrodes for enhanced water desalination through capacitive deionization

2018 ◽  
Vol 19 (4) ◽  
pp. 1221-1228 ◽  
Author(s):  
Jaqueline O. Brotto ◽  
Natan Padoin ◽  
Carlos R. Rambo ◽  
Cíntia Soares
Keyword(s):  
Driving Force ◽  
Water Desalination ◽  
Carbon Electrodes ◽  
Capacitive Deionization ◽  
Concentrated Solutions ◽  
Time Scanning ◽  
Saline Solutions ◽  
Kinetics Of ◽  
Simulated Seawater ◽  
Over Time

Abstract This work reports the preparation of rattan-derived carbon electrodes and their application in capacitive deionization technology for desalination. Desalination tests were performed with different concentrations of simulated seawater in a continuous mode with gravity as the driving force and applied voltages of 0.8 and 1.2 V. Electrosorption kinetics were performed to verify desalination of the saline solutions over time. Scanning electron microscopy revealed that the microstructure of the biomorphic carbon is composed of porous microchannels with diameters of around 300 mm, which allowed both fluid flow and ion retention. The kinetics of the electrosorption presented excellent results concerning desalination of highly concentrated solutions using low voltages.

scholarly journals Diffusion-bonded CNT carpets for fundamental CDI studies

2012 ◽  
Vol 1407 ◽  
Author(s):  
R. Enright ◽  
R. Mitchell ◽  
H. Mutha ◽  
C. Lv ◽  
M. Christiansen ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Nanotube ◽  
Pore Structure ◽  
Electrochemical Capacitor ◽  
Water Desalination ◽  
Carbon Electrodes ◽  
Aqueous Electrolytes ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Multi Scale

ABSTRACTUncertainty about future energy and water supplies suggests a pressing need to develop efficient technologies for water desalination. Capacitive deionization (CDI), a method that captures ions in the electrical double layer (EDL) of an electrochemical capacitor, is a promising technology that can potentially fulfill those requirements. Similar to supercapacitors, ideal CDI electrodes should have a large electrolyte-accessible specific surface area available for ion adsorption with rapid charging/discharging characteristics. Unlike supercapacitors, CDI electrodes are required to operate in aqueous electrolytes with low ionic concentrations in a non-linear charging regime. To explore this practically and theoretically important regime, we developed robust, electrochemically-compatible carbon nanotube (CNT) carpet electrodes that posses a well-defined and uniform pore structure that is more readily analyzed in comparison to the random and multi-scale pore structure of typical carbon electrodes. The fabricated electrodes were characterized using cyclic voltammetry and potentiostatic charging in aqueous NaCl solutions (no = 20 - 90 mM) using a three electrode setup. Examination of the CV and potentiostatically-measured capacitances were consistent with EDL behavior dictated by the Stern layer. However, some deviations from the expected behavior were observed with increasing salt concentration during potentiostatic testing.

scholarly journals Water Desalination Using Capacitive Deionization with Microporous Carbon Electrodes

2012 ◽  
Vol 4 (3) ◽  
pp. 1194-1199 ◽  
Author(s):  
S. Porada ◽  
L. Weinstein ◽  
R. Dash ◽  
A. van der Wal ◽  
M. Bryjak ◽  
...  
Keyword(s):  
Microporous Carbon ◽  
Water Desalination ◽  
Carbon Electrodes ◽  
Capacitive Deionization

High-performance water desalination of heteroatom nitrogen- and sulfur-codoped open hollow tubular porous carbon electrodes via capacitive deionization

2019 ◽  
Vol 6 (11) ◽  
pp. 3359-3373 ◽  
Author(s):  
Qing Zhang ◽  
Yajing Huang ◽  
Dehua Xia ◽  
Lingling Hu ◽  
Ping Li ◽  
...  
Keyword(s):  
Electrode Material ◽  
Porous Carbon ◽  
High Performance ◽  
Tubular Structure ◽  
Water Desalination ◽  
Carbon Electrodes ◽  
Capacitive Deionization ◽  
Porous Carbon Electrodes ◽  
Promising Electrode Material

Heteroatom nitrogen- and sulfur-codoped porous carbon with a unique open hollow tubular structure is a promising electrode material for water desalination in CDI systems.

The Staging of Large Wastewater Treatment Plants - A “Modular” Approach

1992 ◽  
Vol 25 (4-5) ◽  
pp. 67-73
Author(s):  
H. Fleckseder ◽  
L. Prendl ◽  
H. Meulenbroek
Keyword(s):  
Wastewater Treatment ◽  
Driving Force ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Modular Approach ◽  
Central European ◽  
Plant Hydraulics ◽  
The World ◽  
Whole Life Cycle ◽  
Over Time

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.

Dynamic Transformation of Austenite at Temperatures above the Ae3

2018 ◽  
Vol 941 ◽  
pp. 633-638
Author(s):  
John Joseph Jonas ◽  
Clodualdo Aranas Jr. ◽  
Samuel F. Rodrigues
Keyword(s):  
Electron Microscopy ◽  
Driving Force ◽  
Energy Difference ◽  
Accelerated Cooling ◽  
Free Energy Difference ◽  
Dynamic Transformation ◽  
Plate Rolling ◽  
Temperature Transformation ◽  
Mn Steel ◽  
Kinetics Of

Under loading above the Ae3 temperature, austenite transforms displacively into Widmanstätten ferrite. Here the driving force for transformation is the net softening during the phase change while the obstacle consists of the free energy difference between austenite and ferrite as well as the work of shear accommodation and dilatation during the transformation. Once the driving force is higher than the obstacle, phase transformation occurs. This phenomenon was explored here by means of the optical and electron microscopy of a C-Mn steel deformed above their transformation temperatures. Strain-temperature-transformation (STT) curves are presented that accurately quantify the amount of dynamically formed ferrite; the kinetics of retransformation are also specified in the form of appropriate TTRT diagrams. This technique can be used to improve the models for transformation on accelerated cooling in strip and plate rolling.

scholarly journals Kinetics of Anti-SARS-CoV-2 Antibody Responses 3 Months Post Complete Vaccination with BNT162b2; A Prospective Study in 283 Health Workers

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1942
Author(s):  
Evangelos Terpos ◽  
Ioannis P. Trougakos ◽  
Vangelis Karalis ◽  
Ioannis Ntanasis-Stathopoulos ◽  
Sentiljana Gumeni ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Health Workers ◽  
Antibody Responses ◽  
Healthy Individuals ◽  
Younger Age ◽  
Constant Rate ◽  
Rate Of Decline ◽  
A Prospective Study ◽  
Kinetics Of ◽  
Over Time

The aim of this study was to investigate the kinetics of neutralizing antibodies (NAbs) and anti-SARS-CoV-2 anti-S-RBD IgGs up to three months after the second vaccination dose with the BNT162b2 mRNA vaccine. NAbs and anti-S-RBD levels were measured on days 1 (before the first vaccine shot), 8, 22 (before the second shot), 36, 50, and three months after the second vaccination (D111) (NCT04743388). 283 health workers were included in this study. NAbs showed a rapid increase from D8 to D36 at a constant rate of about 3% per day and reached a median (SD) of 97.2% (4.7) at D36. From D36 to D50, a slight decrease in NAbs values was detected and it became more prominent between D50 and D111 when the rate of decline was determined at −0.11 per day. The median (SD) NAbs value at D111 was 92.7% (11.8). A similar pattern was also observed for anti-S-RBD antibodies. Anti-S-RBDs showed a steeper increase during D22–D36 and a lower decline rate during D36–D111. Prior COVID-19 infection and younger age were associated with superior antibody responses over time. In conclusion, we found a persistent but declining anti-SARS-CoV-2 humoral immunity at 3 months following full vaccination with BNT162b2 in healthy individuals.

scholarly journals Long-lasting, monovalent-selective capacitive deionization electrodes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Eric N. Guyes ◽  
Amit N. Shocron ◽  
Yinke Chen ◽  
Charles E. Diesendruck ◽  
Matthew E. Suss
Keyword(s):  
Water Treatment ◽  
Ionic Conductivity ◽  
Ion Selectivity ◽  
Single Step ◽  
Carbon Electrodes ◽  
Capacitive Deionization ◽  
Treatment Technologies ◽  
Porous Carbon Electrodes ◽  
Monovalent Ion ◽  
Direct Use

AbstractEmerging water purification applications often require tunable and ion-selective technologies. For example, when treating water for direct use in irrigation, often monovalent Na+ must be removed preferentially over divalent minerals, such as Ca2+, to reduce both ionic conductivity and sodium adsorption ratio (SAR). Conventional membrane-based water treatment technologies are either largely non-selective or not dynamically tunable. Capacitive deionization (CDI) is an emerging membraneless technology that employs inexpensive and widely available activated carbon electrodes as the active element. We here show that a CDI cell leveraging sulfonated cathodes can deliver long-lasting, tunable monovalent ion selectivity. For feedwaters containing Na+ and Ca2+, our cell achieves a Na+/Ca2+ separation factor of up to 1.6. To demonstrate the cell longevity, we show that monovalent selectivity is retained over 1000 charge–discharge cycles, the highest cycle life achieved for a membraneless CDI cell with porous carbon electrodes to our knowledge, while requiring an energy consumption of ~0.38 kWh/m3 of treated water. Furthermore, we show substantial and simultaneous reductions of ionic conductivity and SAR, such as from 1.75 to 0.69 mS/cm and 19.8 to 13.3, respectively, demonstrating the potential of such a system towards single-step water treatment of brackish and wastewaters for direct use in irrigation.

scholarly journals kinetics of anti-SARS-CoV-2 antibodies over time. Results of 10 month follow up in over 300 seropositive Health Care Workers

2021 ◽  
Author(s):  
Jose Felipe Varona ◽  
Rodrigo Madurga ◽  
Francisco Peñalver ◽  
Elena Abarca ◽  
Cristina Almirall ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Care Workers ◽  
Kinetics Of ◽  
Over Time
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