Induced-polarization measurements on unconsolidated sediments from a site of active hydrocarbon biodegradation

Geophysics ◽  
2006 ◽  
Vol 71 (2) ◽  
pp. H13-H24 ◽  
Author(s):  
Gamal Z. Abdel Aal ◽  
Lee D. Slater ◽  
Estella A. Atekwana
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Acid Leaching ◽  
Induced Polarization ◽  
Microbial Processes ◽  
Microbial Colonization ◽  
Unconsolidated Sediments ◽  
Hydrocarbon Biodegradation ◽  
Electrical Measurements ◽  
A Site

To investigate the potential role that indigenous microorganisms and microbial processes may play in altering lowfrequency electrical properties, induced-polarization (IP) measurements in the frequency range of 0.1 to 1000 Hz were acquired from sediment samples retrieved from a site contaminated by hydrocarbon undergoing intrinsic biodegradation. Increased imaginary conductivity and phase were observed for samples from the smear zone (contaminated with residual-phase hydrocarbon), exceeding values obtained for samples contaminated with dissolved-phase hydrocarbons, and in turn, exceeding values obtained for uncontaminated samples. Real conductivity, although generally elevated for samples from the smear zone, did not show a strong correlation with contamination. Controlled experiments on uncontaminated samples from the field site indicate that variations in surface area, electrolytic conductivity, and water content across the site cannot account for the high imaginary conductivity observed within the smear zone. We suggest that microbial processes may be responsible for the enhanced IP response observed at contaminated locations. Scanning electron microscopy and IP measurements during acid leaching indicate that etched pits on mineral surfaces — caused by the production of organic acids or formed during microbial colonization of these surfaces — are not the cause of the IP enhancement. Rather, we postulate that the accumulation of microbial cells (biofilms) with high surface area at the mineral-electrolyte interface generates the IP response. These findings illustrate the potential use of electrical measurements to noninvasively monitor microbial activity at sites undergoing natural hydrocarbon degradation.

Novel Approach for Synthesis of Mesoporous γ-AlOOH Powder from Coal-Bearing Kaolinite and its Enhanced Adsorption Performance for Congo Red and Fluoride

2019 ◽  
Vol 288 ◽  
pp. 79-86 ◽  
Author(s):  
Quan Lai Yin ◽  
Si Qin Zhao ◽  
Sin Asuha
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Acid Leaching ◽  
Value Added ◽  
Average Crystallite Size ◽  
Bet Surface Area ◽  
Naturally Occurring ◽  
Novel Approach ◽  
Enhanced Adsorption

Mesoporous boehmite (γ-AlOOH) was synthesized from naturally occurring coal-bearing kaolinite (CBK) by direct sulfuric acid leaching and hydrothermal method to explore a new possible route to the synthesis of product with high value added using the CBK. The Brunauner-Emmett-Teller (BET) surface area and the average crystallite size of the γ-AlOOH powder could be controlled in the range from 6.3 to 192.5 m2 g-1 and from 5.5 to 14.4 nm, respectively, by varying the reaction temperature and reaction time. Owing to its porous structure and high surface area, the synthesized mesoporous γ-AlOOH powder exhibited better adsorption abilities for CR and fluoride in contrast to commercial boehmite, and it only took 20 min to reach removal efficiency of 99.6% for CR and 90.5% for fluoride, when the initial concentration of CR and fluoride was 100 and 10 mg L-1, respectively.

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

scholarly journals Rugae-like FeP nanocrystal assembly on a carbon cloth: an exceptionally efficient and stable cathode for hydrogen evolution

Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  
Keyword(s):  
Gas Phase ◽  
Surface Area ◽  
Hydrogen Evolution ◽  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Efficiency ◽  
Carbon Cloth ◽  
Nanocrystal Assembly

High surface area FeP nanosheets on a carbon cloth were prepared by gas phase phosphidation of electroplated FeOOH, which exhibit exceptionally high catalytic efficiency and stability for hydrogen generation.

High Surface Area NiCoP Nanostructure as Efficient Water Splitting Electrocatalyst for the Oxygen Evolution Reaction

2021 ◽  
pp. 111312
Author(s):  
Sisir Maity ◽  
Dheeraj Kumar Singh ◽  
Divya Bhutani ◽  
Suchitra Prasad ◽  
Umesh V. Waghmare ◽  
...  
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Surface ◽  
High Surface Area

scholarly journals Fast synthesis of high surface area bio-based porous carbons for p-nitrophenol removal

MethodsX ◽  
2021 ◽  
pp. 101464
Author(s):  
Yichen Wu ◽  
Nan Zhang ◽  
Charles-François de Lannoy
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Porous Carbons ◽  
Fast Synthesis

Synthesis of high surface area and functionalized nanoporous biocarbons and their efficiency for CO2 capture and supercapacitors

2021 ◽  
Author(s):  
Gurwinder Singh ◽  
Rohan Bahadur ◽  
Ajanya Maria Ruban ◽  
Jefrin Marykala Davidraj ◽  
Dawei Su ◽  
...  
Keyword(s):  
Energy Storage ◽  
Surface Area ◽  
Co2 Capture ◽  
Water Purification ◽  
High Surface ◽  
High Surface Area ◽  
Energy Storage And Conversion ◽  
Waste Biomass ◽  
Fabrication Technology ◽  
Significant Attention

Nanoporous biocarbons derived from waste biomass have created significant attention owing to their great potential for energy storage and conversion and water purification. However, the fabrication technology for these materials...

scholarly journals Developing Eco-Friendly and Cost-Effective Porous Adsorbent for Carbon Dioxide Capture

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1962
Author(s):  
Mahboubeh Nabavinia ◽  
Baishali Kanjilal ◽  
Noahiro Fujinuma ◽  
Amos Mugweru ◽  
Iman Noshadi
Keyword(s):  
Carbon Dioxide ◽  
Surface Area ◽  
Co2 Capture ◽  
High Surface ◽  
Scale Up ◽  
Polymer Networks ◽  
High Surface Area ◽  
Excellent Thermal Stability ◽  
Doped Polymers ◽  
Metal Doped

To address the issue of global warming and climate change issues, recent research efforts have highlighted opportunities for capturing and electrochemically converting carbon dioxide (CO2). Despite metal doped polymers receiving widespread attention in this respect, the structures hitherto reported lack in ease of synthesis with scale up feasibility. In this study, a series of mesoporous metal-doped polymers (MRFs) with tunable metal functionality and hierarchical porosity were successfully synthesized using a one-step copolymerization of resorcinol and formaldehyde with Polyethyleneimine (PEI) under solvothermal conditions. The effect of PEI and metal doping concentrations were observed on physical properties and adsorption results. The results confirmed the role of PEI on the mesoporosity of the polymer networks and high surface area in addition to enhanced CO2 capture capacity. The resulting Cobalt doped material shows excellent thermal stability and promising CO2 capture performance, with equilibrium adsorption of 2.3 mmol CO2/g at 0 °C and 1 bar for at a surface area 675.62 m2/g. This mesoporous polymer, with its ease of synthesis is a promising candidate for promising for CO2 capture and possible subsequent electrochemical conversion.

Gold nanoparticles grown on hydrophobic and texturally-tunable PDMS-like framework

2021 ◽  
Author(s):  
Marieme Kacem ◽  
Nadia Katir ◽  
Jamal El Haskouri ◽  
Abdellatif Essoumhi ◽  
Abdelkrim El Kadib
Keyword(s):  
Gold Nanoparticles ◽  
Surface Area ◽  
Metal Clusters ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Silicas

Mesoporous silicas are among the most suitable high-surface area solids to support small-sized metal clusters and nanoparticles. Unfortunately, the instability of silica in water constitutes a serious impedement for its...

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