Decolorization of molasses spent using a novel adsorbent

Abstract

Removal of melanoidins pigments from molasses spent wash was investigated using a new adsorbent.
Solid adsorbents were fabricated from charcoal fly ash and clay with the proportion of 60 and 40 weight
percent. The fabricated adsorbents were packed in a column and the molasses solution was pumped
through the column. The impact of various contact times of the pigments and the adsorbents in the
column on color removal efficiency was investigated. The experiments were conducted with various
contact times of 30, 60, 90 and 240 min. Also, the effect of influent molasses concentration on the
performance of the adsorbents was evaluated. The effluent samples were taken from the column at a time
interval of 30 min. The obtained results revealed that maximum color removal efficiency of 72% was
achieved with molasses concentration of 6 g/l and contact time of 240 min. The obtained results from the
fresh and regenerated adsorbents were compared. The achieved data showed that 90% of the capacity of
the fresh adsorbent was recovered after the regeneration process. It was also concluded that the
regenerated adsorbents were able to remove 65% of the color from the molasses solution. Langmuir and
Freundlich isotherm adsorption models were investigated to interpret the experimental data. The obtained
data were well represented by Langmuir adsorption model. The constants of the isotherms and the
maximum adsorption capacity of the adsorbents were calculated.