Modeling of Fixed-bed Column Studies for the Adsorption of Cadmium onto Novel Polymer–clay Composite Adsorbent.
Loading...
Date
2010-03
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Kaolinite clay was treated with polyvinyl alcohol to produce a novel water-stable composite
called polymer–clay composite adsorbent. The modified adsorbent was found to have a maximum
adsorption capacity of 20,400 ± 13 mg/L (1236 mg/g) and a maximum adsorption rate constant of
≈7.45 × 10−3 ± 0.0002 L/(min mg) at 50% breakthrough. Increase in bed height increased both the breakpoint and exhaustion point of the polymer–clay composite adsorbent. The time for the movement of the
Mass Transfer Zone (ı) down the column was found to increase with increasing bed height. The presence
of preadsorbed electrolyte and regeneration were found to reduce this time. Increased initial Cd2+ concentration, presence of preadsorbed electrolyte, and regeneration of polymer–clay composite adsorbent
reduced the volume of effluent treated. Premodification of polymer–clay composite adsorbent with Caand Na-electrolytes reduced the rate of adsorption of Cd2+ onto polymer–clay composite and lowered the
breakthrough time of the adsorbent. Regeneration and re-adsorption studies on the polymer–clay composite adsorbent presented a decrease in the bed volume treated at both the breakpoint and exhaustion
points of the regenerated bed. Experimental data were observed to show stronger fits to the Bed Depth
Service Time (BDST) model than the Thomas model.
Description
Keywords
Adsorption, Polymer–clay composite, Kaolinite, Breakthrough, Mass transfer, Fixed-bed, Regeneration, Model