A comparative study of copper(II) biosorption on Ca-alginate, agarose and immobilized C. vulgaris in a packed-bed column

1998 ◽  
Vol 33 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Z. Aksu ◽  
G. Eğretli ◽  
T. Kutsal
2006 ◽  
Vol 514-516 ◽  
pp. 1294-1298 ◽  
Author(s):  
Maria Teresa Tavares ◽  
Cristina Quintelas ◽  
Hugo Figueiredo ◽  
Isabel Neves

This study aims the definition of a new material that may act as a robust and yet cost effective biosorbent for treatment of wastewater with low concentration of heavy metals. A comparative study was made between two biosorption systems composed of an Arthrobacter viscosus biofilm supported on Cuban natural zeolites and on prepared NaY and NaX, in terms of their ability to retain ionic chromium. The bacterium is able to reduce Cr(VI) to Cr(III) and, only then, this smaller and positive ion may be entrapped in the zeolite cages by ion exchange. The first support was tested in a continuous flow semi-packed bed column. The highest removal ratio, 42%, was achieved for initial chromium concentration of 10 mg/L, but the best up-take, 5.5 mg/gzeolite, was obtained for initial concentration of 70 mg/L. Biosorbents prepared with the same biofilm supported in NaY and NaX zeolites were also considered in batch studies, with a typical kinetics of biosorption processes, reaching 20% of initial chromium removal within an initial range of Cr(VI) concentration between 50 and 250 mg/L. These last structures were characterized by spectroscopic methods (FTIR and ICP-AES), surface analysis (DRX) and thermal analysis (TGA). All these techniques indicated that the biosorption process does not modify the morphology and structure of the FAU-zeolites.


1986 ◽  
Vol 51 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.


1982 ◽  
Vol 47 (10) ◽  
pp. 2639-2653 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk

Expressions have been derived for four possible transfer functions of a model of physical absorption of a poorly soluble gas in a packed bed column. The model has been based on axially dispersed flow of gas, plug flow of liquid through stagnant and dynamic regions and interfacial transport of the absorbed component. The obtained transfer functions have been transformed into the frequency domain and their amplitude ratios and phase lags have been evaluated using the complex arithmetic feature of the EC-1033 computer. Two of the derived transfer functions have been found directly applicable for processing of experimental data. Of the remaining two one is useable with the limitations to absorption on a shallow layer of packing, the other is entirely worthless for the case of poorly soluble gases.


1987 ◽  
Vol 52 (7) ◽  
pp. 1715-1729 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk

An experimental method and technique are described in the paper of simultaneous detection of the transfer functions outlet-gas-stream-to-inlet-gas-stream and outlet-liquid-stream-to-inlet-gas-stream for the absorption of oxygen into water in a counter-current packed bed column. Both transfer functions were simultaneously monitored by means of three oxygen electrodes operating on the polarographic principle. The signals of these electrodes were processed in three steps to yield parameters of the model of physical absorption of gas. The first step was on-line evaluation of the Fourier coefficients of the principal harmonic component in all three monitored streams. The second step was the calculation of the frequency characteristics of both transfer functions while the third step yielded parameters of the model by optimization in the frequency domain. The method permits simultaneous evaluation of the parameters of the flow of both phases in the column and the interfacial transfer of oxygen.


2020 ◽  
Vol 17 (4) ◽  
pp. 47-52
Author(s):  
Vibha Goswami ◽  
Renu Upadhyaya ◽  
Sumanta Kumar Meher

In this study, synthesised Azadirachta indica adsorbent was used for the removal of methylene blue dye using a packed bed column. The effect of feed flow rate, feed methylene blue dye concentration, and bed height of column on percentage removal of dye was studied. It was observed that the column bed exhausted rapidly at a higher flow rate and therefore, a breakthrough occurred faster. However, it was observed that bed exhaustion time increases on increasing the bed height from 2 to 10 inch at 10 mg/L feed dye concentration and feed flow rate of 40 ml/min. It was also found that the breakthrough curve is more dispersed and the percentage removal of dye increases on decreasing the feed methylene dye concentration from 150 to 10 mg/L. The percentage removal was found to be 96.89% at 20 ml/min of feed flow rate under 10 inch of bed height and 10 mg/L of feed dye concentration. The atomic absorption spectrophotometer and scanning electron microscope were used for estimating the effluent dye concentration from the column and morphological study, respectively.


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