Adsorption-Anaerobic Digestion coupling process for molasses vinasse Treating
No Thumbnail Available
Date
2018-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The production of ethanol from biomass results in the co-current production of acidic material
known as distillery spent wash or vinasse. It is generated at a rate of 10 to 15 times greater than
the ethanol itself, and is characterized by a high dissolved organic matter content. Anaerobic
digestion is the most effective methods for the treatment of such type of wastewater. In this work,
a combined adsorption–anaerobic digestion treatment of distillery wastewater was studied in order
to develop an effective procedure for increasing the anaerobic biodegradability of vinasse to reduce
its environmental impact. The adsorption stage with banana peel as a pretreatment was evaluated
for removal of phenolic compound. The removal of phenolic compound with this biosorbent was
carried out using Box-Behnken experimental design taking 3 factors, adsorbent dose, contact time,
and particle size. The maximum phenol removal recorded was 76.425% at the optimum condition
(adsorbent dose of 20 g/L, contact time of 129.98 min, and particle size of 0.53 mm). Removals
of 22% in chemical oxygen demand (COD) was obtained in this stage. Among the adsorption
isotherm models analyzed, the Langmuir model fitted best to the experimental data with maximum
adsorption capacity of 4.12 mg/g, and also the adsorption mechanism follows pseudo-second order
model. The pretreated vinasse was undergone to an anaerobic digestion process in the second stage
under mesophilic condition. After anaerobic digestion, a global removal of 84% in COD, and over
95% in phenols content were obtained. It was shown that, a combination of treatment method (i.e.
banana peel biosorption and anaerobic digestion) is a promising option for simultaneous removal
of phenol and COD from molasses vinasse under the stated conditions.
Description
Keywords
molasses vinasse Treating, Adsorption-Anaerobic Digestion, coupling process