scholarly journals Comparing hexacyanoferrate loaded onto silica, silicotitanate and chabazite sorbents for Cs extraction with a continuous-flow fixed-bed setup: Methods and pitfalls

2020 ◽  
Vol 134 ◽  
pp. 371-380 ◽  
Author(s):  
Agnès Grandjean ◽  
Yves Barré ◽  
Audrey Hertz ◽  
Virginie Fremy ◽  
Jérémy Mascarade ◽  
...  
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1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.


2021 ◽  
Vol 50 (7) ◽  
pp. 2493-2500
Author(s):  
Sara Rojas ◽  
Jorge A. R. Navarro ◽  
Patricia Horcajada

A defective Metal-Organic Frameworks as an improved material for the construction of a fixed-bed system working under continuous flow conditions for the removal of the emerging contaminant atenolol.


1995 ◽  
Vol 32 (8) ◽  
pp. 205-212 ◽  
Author(s):  
A. Wobus ◽  
S. Ulrich ◽  
I. Röske

Two identical fixed bed reactors containing gas-permeable tubings as carrier material were compared for the elimination of chlorophenols. Under plug flow conditions, the continuous flow operation resulted in a stratification of biomass due to concentration gradients. To achieve a homogeneous colonization, the sequencing batch mode has been applicated to one biofilm reactor (Sequencing Batch Biofilm Reactor - SBBR). Concentration gradients after filling, probably due to sorption phenomena, caused an uneven distribution of biomass in the SBBR. However, the colonization of the SBBR was more homogeneous as compared to the continuously operated reactor (CFBR). As to the elimination of a trichlorophenol (2,4,5-trichlorophenol - TCP), no significant differences between the SBBR and the CFBR were observed with regard to its sensitivity against load surges. It is to be supposed that sorption to the biofilm was included in the elimination of chlorophenols. A higher diversity of protozoan community and meiofauna is obviously to be attributed to continuous flow.


Author(s):  
Suttikorn Suwannatrai ◽  
Dickson Y. S. Yan ◽  
Pummarin Khamdahsag ◽  
Visanu Tanboonchuy

Arsenite (As(III)) has threatened human life for ages. It is a necessity to remove As(III) from the contaminated water before general use. With the improvement of adsorption, higher As(III) removal can be achieved. This study aimed to develop zeolite/cerium oxide coat-on activated alumina ball adsorbent (CeZ-ball) with the aid of PVA binder and apply it to a fixed-bed continuous flow column for As(III) adsorption. The coating percentage of CeZ-ball was studied. Cerium ions leaching from CeZ-ball were monitored throughout the 2,880-min-column run to confirm the stability of CeZ attached to an activated alumina ball. Surface area, pH point of zero charge, and structural property of CeZ-ball were characterized. An average CeZ coating of 83.3% and rare leaching of cerium proved the coating method. The models proposed by Yoon-Nelson provided the most satisfactory fit with the breakthrough curve (r2 = 0.985, MPSD = 2.547, and q0 = 3.481 mg·g–1) under experimental conditions of the flow rate of 5 mL·min–1, As(III) influent concentration of 1 mg·L–1, and CeZ-ball weight of 40 g. The half-time of breakthrough (τ) was 1,228.739 min. The effects of the key parameters, including initial adsorbent weight, initial flow rate, and initial As(III) concentration, were investigated for the performance of As(III) adsorption. Simulated from the Yoon-Nelson model, the τ increased as well as the adsorbent weight but decreased as the flow rate increased, thus impacting the As(III) concentration. With the optimal condition, the fixed-bed continuous column with CeZ-ball could be used in As(III) removal from contaminated water.


2021 ◽  
Vol 231 ◽  
pp. 116303
Author(s):  
Jiangbo Xi ◽  
Qijun Wang ◽  
Xianming Duan ◽  
Ning Zhang ◽  
Junxia Yu ◽  
...  

2011 ◽  
Vol 39 (8) ◽  
pp. 774-780 ◽  
Author(s):  
Alfredo Gallego ◽  
Virginia L. Gemini ◽  
Susana L. Rossi ◽  
Carlos E. Gómez ◽  
Gustavo D. Bulus Rossini ◽  
...  
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