Adsorption Modeling Of Breakthrough Curves

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Adsorption modeling of breakthrough curves A successful design of a column adsorption process requires prediction of the concentration-time profile or breakthrough curve for the effluent. (a,aa14, aa15, aa7, aa2). There are two widely used approaches to obtain the breakthrough curve of a given adsorption system: direct experimentation or mathematical modeling. The design of an adsorption column through experimental method provides a direct determination of the salient parameters based on the breakthrough curve. However, the extensive experimentation is usually a time-consuming and economically unfeasible. (B6 ) Comparatively, mathematical modeling is simple and provides a method of estimating the column adsorption capacity without…show more content…
A linear regression was applied to equation 4 and the values of No and ka were computed from the slope and intercept of the BDST plot between ln(Co/Ct -1) versus t at different adsorption parameters such as flow rate, bed height and influent adsorbate concentration. These BDST parameters were used to predict the maximum metal uptake capacity (qcal) under different process conditions and were compared with the experimental values (qexp) in relation to the estimated values of ka and No. As shown in Table 1a and b, the values ka decreased with increasing bed depth and influent metal concentration, but increase with increasing flow rates. Meanwhile, the values of No declined with the increase in bed height and flow rate. This trend can be explained on the fact that at increased bed heights more number of active sites is available for sorption to give higher total metal uptake but reduced per unit removal, whereas at increased flow rate the volume of adsorbate that entered the column was higher and caused the bed to saturate early. As with increased metal concentration, the No values were found to be increasing due to higher loading of metal on the adsorbent achieved in a short period of contact. This discussion shows that the overall kinetics of adsorption process is governed by external mass transfer. (aa26, aa7,aa14, aa27) The BDST model is valid for the describing the initial part of breakthrough curve
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