Characterization of a photocatalytic reaction in a continuous-flow recirculation reactor system

In this paper, we present a new FTIR-based microfluidic system for Glucose, Fructose and Sucrose detection. The proposed microfluidic system is based on a pseudo-continuous flow coupled to a microscope-FTIR instrument. The detection and characterization of sugar samples were performed by recording their absorption spectrum in the wavelength range 700–1000 cm − 1 of the Mid-IR region. The proposed pseudo-continuous flow system is designed to improve the uniformity of the sample distribution in the analyzed area versus conventional systems. The obtained results for different sugars concentrations, show a very low measurement error of 4.35% in the absorption peak intensity, which is ten times lower than the error obtained using the conventional measurements.

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Detailed experimental and numerical characterization of turbulent flow in components of a water treatment plant

Water Science & Technology ◽

10.2166/wst.2020.013 ◽

2019 ◽

Vol 80 (11) ◽

pp. 2117-2130

Author(s):

Ivan Matías Ragessi ◽

Carlos Marcelo García ◽

Santiago Márquez Damián ◽

Cecilia Pozzi Piacenza ◽

Mariano Ignacio Cantero

Keyword(s):

Water Treatment ◽

Turbulent Flow ◽

Treatment Plant ◽

Acoustic Doppler Current Profiler ◽

Water Treatment Plant ◽

Mean Flow ◽

Cross Sectional ◽

Flow Recirculation ◽

Hydraulic Design

Abstract This paper presents a detailed characterization of turbulence in the incoming flow to the clarification component of a water treatment plant, ‘Los Molinos’ (Córdoba, Argentina). The main problems were related to the presence of turbulent flow patterns throughout the treatment, affecting the proper development of the physical processes required for water clarification. Namely: (a) a poor hydraulic design that could produce a non-homogeneous spatial distribution of the flow, recirculation zones and flow stagnation, and a non-uniform discharge distribution among the sedimentation units as a result of different cross-sectional dimensions of the transverse-channel, and (b) high turbulence intensity that affect the flocs' size as well as the efficiency of the settling tanks and filters. Firstly, a detailed in-situ experimental characterization of the turbulent flow was undertaken. An acoustic Doppler velocimeter (ADV) was used to characterize the flow turbulence, whereas for discharge measurements and mean flow velocity field an acoustic Doppler current profiler (ADCP) was employed. Secondly, a numerical model, based on the Reynolds-averaged Navier–Stokes (RANS) equations and the - turbulence closure model, was validated with the experimental data. Finally, based on the results, a diagnosis and recommendations were made for the optimization of the hydraulic design of the water treatment plant.

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Catalytic Hydrodechlorination of Chlorophenols in a Continuous Flow Pd/CNT-Ni Foam Micro Reactor Using Formic Acid as a Hydrogen Source

Catalysts ◽

10.3390/catal9010077 ◽

2019 ◽

Vol 9 (1) ◽

pp. 77 ◽

Cited By ~ 3

Author(s):

Jun Xiong ◽

Ying Ma

Keyword(s):

Catalytic Activity ◽

Formic Acid ◽

Continuous Flow ◽

Catalyst Surface ◽

Reactor System ◽

Packed Bed Reactor ◽

Pd Catalyst ◽

Ni Foam ◽

Catalytic Hydrodechlorination ◽

Micro Reactor

Catalytic hydrodechlorination (HDC) has been considered as a promising method for the treatment of wastewater containing chlorinated organic pollutants. A continuous flow Pd/carbon nanotube (CNT)-Ni foam micro reactor system was first developed for the rapid and highly efficient HDC with formic acid (FA) as a hydrogen source. This micro reactor system, exhibiting a higher catalytic activity of HDC than the conventional packed bed reactor, reduced the residence time and formic acid consumption significantly. The desired outcomes (dichlorination >99.9%, 4-chlorophenol outlet concentration <0.1 mg/L) can be obtained under a very low FA/substrate molar ratio (5:1) and short reaction cycle (3 min). Field emission scanning electron microcopy (FESEM) and deactivation experiment results indicated that the accumulation of phenol (the main product during the HDC of chlorophenols) on the Pd catalyst surface can be the main factor for the long-term deactivation of the Pd/CNT-Ni foam micro reactor. The catalytic activity deactivation of the micro reactor could be almost completely regenerated by the efficient removal of the absorbed phenol from the Pd catalyst surface.

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Design of a microfluidic device for the measurement of the elastic modulus of deformable particles

Soft Matter ◽

10.1039/c8sm02272k ◽

2019 ◽

Vol 15 (5) ◽

pp. 880-889 ◽

Cited By ~ 4

Author(s):

Massimiliano M. Villone ◽

Janine K. Nunes ◽

Yankai Li ◽

Howard A. Stone ◽

Pier Luca Maffettone

Keyword(s):

Elastic Modulus ◽

Interfacial Tension ◽

Continuous Flow ◽

Liquid Droplet ◽

Flow Process ◽

Deformable Particles ◽

Soft Particles ◽

Continuous Flow Process ◽

Microfluidic Technique

A microfluidic technique recently proposed in the literature to measure the interfacial tension between a liquid droplet and an immiscible suspending liquid [Hudson et al., Appl. Phys. Lett., 2005, 87, 081905], [Cabral and Hudson, Lab Chip, 2006, 6, 427] is suitably adapted to the characterization of the elastic modulus of soft particles in a continuous-flow process.

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