Twostage batch adsorber design using pseudosecondorder kinetic model for the adsorption of Acid Blue

1
Two-Stage Batch Adsorber Design Using
Pseudo-Second-Order Kinetic Model for the
Adsorption of Acid Blue 25 Dye onto Peat Pei-Yu
Lin1, Ming-Huang Wang1, Yu-Ting Feng1, I-Hsin
Lin1 and Yuh-Shan Ho2 1School of Public Health,
Taipei Medical University 2Bibliometric Centre,
Taipei Medical University - Wan-Fang Hospital
Introduction Batch adsorber design has mainly
concentrated on reducing adsorbent costs, which
is particularly relevant when expensive sorbent
materials such as active carbon, silica, zeolites
and resins are used. But for cheaper adsorbents
minimizing the contact time for a fixed
percentage of pollution removal using a fixed
mass of adsorbent will result in being able to
process more batches of polluted wastewater per
day, thus enabling the required treatment plant
items to be reduced in size, with a decrease in
the plant capital cost. This paper studies the
adsorption of Acid Blue 25 dye onto peat and
develops a two-stage batch adsorber design model.
Methods A 0.5 g sample of peat (500-710 ?m) was
added to each 50 ml volume of Acid Blue 25 (AB25)
dye solution. The initial concentrations of AB25
dye solution tested were 20, 50, 100 and 200
mg/dm3. Samples were withdrawn at suitable time
intervals, filtered through a filter paper and
then analysed AB25 concentration using UV.
Results
Pseudo-second-order kinetic model
Mass balance equation

• Conclusions
• The design model presented is based on a
  pseudo-second-order kinetic model, and this has
  been used for minimizing the reaction time used
  in a two-stage contact system that operating cost
  would be reduced.
• The method proposed in this study enables the
  contact time in a two-stage batch adsorber to be
  minimized to achieve a fixed percentage of Acid
  Blue 25 removal using a fixed mass peat.
• An optimised operating condition, the minimum
  contact time is 191 min, with reaction times of
  100 min for stage 1 and 91 min for stage 2.