Regeneration of ortho-chlorophenol-exhausted activated carbons with liquid water at high pressure and temperature.
ABSTRACT A study was undertaken of the regeneration of three activated carbons exhausted with ortho-chlorophenol. The regeneration process was carried out using liquid water at 623 K and 150 atm in the absence of oxygen. The efficiency of this procedure was analyzed by determining the rate and amount of ortho-chlorophenol adsorbed in successive adsorption-regeneration cycles. The present procedure showed a much greater efficiency than that reported for chemical and/or thermal regeneration. Effects of this regeneration on the adsorption kinetics, adsorption capacity and textural characteristics of the carbon were investigated. The increase in adsorption capacity of the regenerated carbon compared with that of the original carbon seems mainly due to the opening of porosity during the regeneration treatment.
- Bone 01/2011; 48. · 3.82 Impact Factor
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ABSTRACT: This paper provides a review of recent scientific research on the removal by activated carbon (AC) in drinking water (DW) treatment of 1) two classes of currently unregulated trace level contaminants with potential chronic toxicity-pharmaceutically activate compounds (PhACs) and endocrine disrupting compounds (EDCs); 2) cyanobacterial toxins (CyBTs), which are a group of highly toxic and regulated compounds (as microcystin-LR); and 3) the above mentioned compounds by the hybrid system powdered AC/membrane filtration. The influence of solute and AC properties, as well as the competitive effect from background natural organic matter on the adsorption of such trace contaminants, are also considered. In addition, a number of adsorption isotherm parameters reported for PhACs, EDCs and CyBTs are presented herein. AC adsorption has proven to be an effective removal process for such trace contaminants without generating transformation products. This process appears to be a crucial step in order to minimize PhACs, EDCs and CyBTs in finished DW, hence calling for further studies on AC adsorption removal of these compounds. Finally, a priority chart of PhACs and EDCs warranting further study for the removal by AC adsorption is proposed based on the compounds' structural characteristics and their low removal by AC compared to the other compounds.Science of The Total Environment 08/2012; 435-436:509-25. · 3.26 Impact Factor
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ABSTRACT: In this work, a new method, called the preconcentration method (PCM), is proposed to increase the adsorption of protein-bound toxins onto adsorbents in artificial liver support systems. In the PCM, a concentrator is installed before the inlet of the adsorbent cartridge. This method is validated in an experiment using activated carbon to remove albumin-bound bilirubin, and the mechanism of the increase in adsorption is theoretically explained with breakthrough curve and equilibrium adsorption analyses. Our results show that when this PCM is used, the mass transfer rate of bilirubin from solution to activated carbon is enhanced, the adsorbed bilirubin amount per unit mass of activated carbon is greatly increased, and more albumin-bound bilirubin molecules are quickly removed from the albumin solution. When the concentration ratio (the ratio of the inlet flow rate to the outflow rate of the concentrator) is 2.59, the adsorption efficiency of activated carbon at 120 min is increased by approximately 36%. Only approximately 60 min is required for the bilirubin concentration to decrease from 19.3 to 13.0 mg/dL; however, without the PCM, nearly 180 min is needed. In addition, by adjusting the concentration ratio, the adsorption of albumin-bound bilirubin onto activated carbon can be further increased.Artificial Organs 03/2014; · 1.96 Impact Factor