scholarly journals Towards Scaling-up Photocatalytic Process for Multiphase Environmental Applications: A Review

2021 ◽  
Author(s):  
Mohamed Gar Alalm ◽  
Ridha Djellabi ◽  
Daniela Meroni ◽  
Carlo Pirola ◽  
Claudia L. Bianchi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Large Scale ◽  
Research Practice ◽  
Photocatalytic Process ◽  
Practical Application ◽  
Wastewater Purification ◽  
Photocatalytic Reactors ◽  
Practice Gaps ◽  
Critical Overview ◽  
Degradation Of Pollutants

Recently, we have witnessed a booming development of composites and multi-dopant metal oxides to be employed as novel photocatalysts. Yet the practical application of photocatalysis for environmental purposes is still elusive. Concerns about the unknown fate and toxicity of nanoparticles, unsatisfactory performance in real conditions, mass transfer limitations and durability issues have so far discouraged investments in full-scale applications of photocatalysis. Herein, we provide a critical overview of the main challenges that are limiting large-scale application of photocatalysis in air and water/wastewater purification. We then discuss the main approaches reported in the literature to tackle these shortcomings, such as the design of photocatalytic reactors that retain the photocatalyst, the study of degradation of micropollutants in different water matrices, and the development of gas-phase reactors with optimized contact time and irradiation. Furthermore, we provide a critical analysis of research-practice gaps such as treatment of real water and air samples, degradation of pollutants with actual environmental concentrations, photocatalyst deactivation, and cost and environmental life-cycle assessment.

scholarly journals Toward Scaling-Up Photocatalytic Process for Multiphase Environmental Applications

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 562
Author(s):  
Mohamed Gar Alalm ◽  
Ridha Djellabi ◽  
Daniela Meroni ◽  
Carlo Pirola ◽  
Claudia Letizia Bianchi ◽  
...  
Keyword(s):  
Gas Phase ◽  
Large Scale ◽  
Research Practice ◽  
Photocatalytic Process ◽  
Practical Application ◽  
Wastewater Purification ◽  
Photocatalytic Reactors ◽  
Practice Gaps ◽  
Critical Overview ◽  
Degradation Of Pollutants

Recently, we have witnessed a booming development of composites and multi-dopant metal oxides to be employed as novel photocatalysts. Yet the practical application of photocatalysis for environmental purposes is still elusive. Concerns about the unknown fate and toxicity of nanoparticles, unsatisfactory performance in real conditions, mass transfer limitations and durability issues have so far discouraged investments in full-scale applications of photocatalysis. Herein, we provide a critical overview of the main challenges that are limiting large-scale application of photocatalysis in air and water/wastewater purification. We then discuss the main approaches reported in the literature to tackle these shortcomings, such as the design of photocatalytic reactors that retain the photocatalyst, the study of degradation of micropollutants in different water matrices, and the development of gas-phase reactors with optimized contact time and irradiation. Furthermore, we provide a critical analysis of research–practice gaps such as treatment of real water and air samples, degradation of pollutants with actual environmental concentrations, photocatalyst deactivation, and cost and environmental life-cycle assessment.

CO2 Conversion by Membrane Reactors

2019 ◽  
Vol 19 (6) ◽  
pp. 3124-3134
Author(s):  
Adele Brunetti ◽  
Enrica Fontananova
Keyword(s):  
High Temperature ◽  
Membrane Reactor ◽  
Large Scale ◽  
Dry Reforming ◽  
Membrane Reactors ◽  
Dry Reforming Of Methane ◽  
Co2 Conversion ◽  
Promising Tool ◽  
Photocatalytic Reactors ◽  
Critical Overview

Membrane reactors technology represents a promising tool for the CO2 capture and reuse by conversion to valuable products. After a preliminary presentation of the fundamentals of this technology, a critical overview of the last achievements and new perspectives in the CO2 conversion by membrane reactors is given, highlighting the still existing limitations for large scale applications. Among the low temperature (≤100 °C) membrane reactor for CO2 conversion, electrochemical membrane reactors and photocatalytic reactors, represent the two mainly pursued systems and they were discussed starting from selected case studies. Dry reforming of methane and CO2 hydrogenation to methanol were selected as interesting examples of high temperature (>100 °C) membrane based conversion of CO2 to energy bearing products.

Computational challenges of modelling interactions between aerosol and gas phase processes in large‐scale air pollution models

1999 ◽  
Vol 10 (4) ◽  
pp. 224-235 ◽  
Author(s):  
Gregory R. Carmichael ◽  
Adrian Sandu ◽  
Chul H. Song ◽  
Shan He ◽  
Mahesh J. Phadnis ◽  
...  
Keyword(s):  
Air Pollution ◽  
Gas Phase ◽  
Large Scale ◽  
Air Pollution Models

scholarly journals COLLABORATING AT MICROSCOPIC AND MASSIVE SCALES: THE CHALLENGE AND VALUE OF COVID ISOLATION FOR CRITICAL INTERNET STUDIES

2021 ◽  
Author(s):  
Andrew Herman ◽  
Annette Markham ◽  
M.E. Luka ◽  
Rebecca Carlson ◽  
Danielle Dilkes ◽  
...  
Keyword(s):  
Critical Pedagogy ◽  
Large Scale ◽  
Microscopic Level ◽  
Early Career ◽  
Research Practice ◽  
Internet Studies ◽  
Early Career Researchers ◽  
Independent Life ◽  
Global Events ◽  
Collaborative Space

Global events like a pandemic or climate change are massive in scope but experienced at the local, lived, microscopic level. What sorts of methodologies and mindsets can help critical internet researchers, functioning as interventionists or activists, find traction by oscillating between these levels? How can we push (further) against the boundaries of research methods to build stronger coalitions and more impactful outcomes for social change among groups of scholars/researchers? This panel presents four papers addressing these questions based on a large scale online autoethnography in 2020. This “Massive/Micro” project simultaneously used and studied the angst and novelty of isolation during a pandemic, activating researchers, activists, and artists to explore the massive yet microscopic properties of COVID-19 as a “glocal” phenomenon. The challenge? Working independently and microscopically through intense focus on the Self but also working with distributed, largely unknown collaborators, in multiple platforms. The emerging shape of the project itself showcases the challenges and possibilities of how research projects at scale can (or don’t) reflect and build social movements. The panel’s four papers situate the project through a kaleidoscope of perspectives featuring participants from 7 countries, who variously explore: the value of the project for precarious or early career researchers, how MMS worked as both collaborative space and critical pedagogy, how non-institutional or playful experimentation in asynchronous collaborations can lead to new synergies; and how MMS developed an independent life of its own, beyond studying COVID to generating multiple communities of future digital research practice.

scholarly journals Practical Remote Workflow Solutions for Complex Digital Projects: Opportunities in a Pandemic

Collections ◽  
2021 ◽  
pp. 155019062110527
Author(s):  
J.A. Pryse
Keyword(s):  
Large Scale ◽  
The Political ◽  
Workflow Model ◽  
Practical Application ◽  
Pilot Phase ◽  
Digital Videos ◽  
On Line ◽  
Systematic Solution ◽  
Long Term Preservation

The spread of COVID-19 has created numerous challenges in the field of archive management. Limited in-house office space, furloughs of personnel, and inconsistency, has highlighted the potential for the Carl Albert Congressional Research and Studies Center Archives (Center) to develop and implement improved accessibility measures to thousands of linear feet of material. Addition ally, the Center has found unique opportunities to collaborate with multiple academic institutions to propose large-scale digitization program exhibitions using the Center’s remote workflow model. One of the largest, most complex collections the Center has worked with during this time is the Political Commercial Collection (the Collection), which holds 119,000 film, audio, and videotape recordings of commercials aired between 1936 and present. It is the largest collection of political commercials in the world. The Center has developed a working pilot digitization project that has currently resulted in access to 16,000 digital videos for public researchers and over 10,000 available for on-line streaming during the pilot phase between April 16, 2020, and December 1, 2020. This paper presents the practical application of the Center’s simplified “Linear Reciprocity Workflow Model” to provide a systematic solution for digital and long-term preservation of complex collections. The Center has proven that limited personnel and reduced resources need not interrupt continued access to archival repositories.

scholarly journals Ultrathin Tropical Tropopause Clouds (UTTCs): I. Cloud morphology and occurrence

2003 ◽  
Vol 3 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
Th. Peter ◽  
B. P. Luo ◽  
M. Wirth ◽  
C. Kiemle ◽  
H. Flentje ◽  
...  
Keyword(s):  
Gas Phase ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Western Indian Ocean ◽  
Ice Crystals ◽  
Mixing Ratio ◽  
Efficient Point ◽  
Tropical Tropopause ◽  
Cold Point

Abstract. Subvisible cirrus clouds (SVCs) may contribute to dehydration close to the tropical tropopause. The higher and colder SVCs and the larger their ice crystals, the more likely they represent the last efficient point of contact of the gas phase with the ice phase and, hence, the last dehydrating step, before the air enters the stratosphere. The first simultaneous in situ and remote sensing measurements of SVCs were taken during the APE-THESEO campaign in the western Indian ocean in February/March 1999. The observed clouds, termed Ultrathin Tropical Tropopause Clouds (UTTCs), belong to the geometrically and optically thinnest large-scale clouds in the Earth's atmosphere. Individual UTTCs may exist for many hours as an only 200--300 m thick cloud layer just a few hundred meters below the tropical cold point tropopause, covering up to 105 km2. With temperatures as low as 181 K these clouds are prime representatives for defining the water mixing ratio of air entering the lower stratosphere.

Use of Experimental Designs to Establish a Kinetic Law for a Gas Phase Photocatalytic Process

2014 ◽  
Vol 12 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Cécile Raillard ◽  
Audrey Maudhuit ◽  
Valérie Héquet ◽  
Laurence Le Coq ◽  
Jean Sablayrolles ◽  
...  
Keyword(s):  
Light Intensity ◽  
Photocatalytic Degradation ◽  
Gas Phase ◽  
Photocatalytic Oxidation ◽  
Experimental Designs ◽  
Photocatalytic Process ◽  
Air Velocity ◽  
Kinetic Rate ◽  
Initial Concentration ◽  
Designs Of Experiments

Abstract The photocatalytic degradation of three common indoor VOCs – acetone, toluene and heptane – is investigated in a dynamic photocatalytic oxidation loop using Box–Behnken designs of experiments. Thanks to the experimental results and the establishment of a kinetic rate law based on a simplified mechanism, a predictive model for the VOC degradation involving independent factors is developed. The parameters under investigation are initial concentration, light intensity and air velocity through the photocatalytic medium. The obtained model fits properly the experimental curves in the range of concentration, light intensity and air flow studied.

Modelling of Soot Formation in Spray Combustors

1983 ◽  
Author(s):  
S. S. Koussa
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Gas Phase ◽  
Soot Formation ◽  
Soot Concentration ◽  
Practical Application ◽  
Combustion Modelling

A model for the prediction of the distribution of soot concentration in spray combustors is presented. Both gas-phase and liquid-phase soot formation have been considered. The methods have been developed within the constraints on detailed combustion modelling for practical application. Some predictions are assessed by comparison with published experimental data. It is concluded that predictions of the same quality as those of gaseous-fuelled combustors may be obtained neglecting liquid-phase soot formation in case of light fuels.

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