Razali, Yasmin Syafikah
(2018)
Acetic And Butyric Acids From
Fermented Leachate By Various
Extraction Methods : Optimization And
Recovery Studies.
Masters thesis, Universiti Sains Malaysia.
Abstract
Carboxylic acids are important because of their wide application in the industries
such as food, pharmaceutical and fragrance industries. Treatment of leachate is using
fermentation process of Clostridium butyricum contains valuable volatile fatty acids
(VFA) which is acetic and butyric acids. Thus, this research focuses on the recovery of
acetic and butyric acids from fermented leachate. The extraction of these VFAs from
fermented leachate by using three extraction methods; aqueous two phase (ATPS),
solvent extraction and adsorption were optimized and compared to determine the best
extraction method. Adsorption by using activated carbon was the best extraction method
at a dosage of 19.79% per 100 ml sample within 9.45 h contact time, pH 3.0 and
agitation speed of 180 rpm. The acetic and butyric acids extracted were 87.91 ± 1.3%
and 98.32 ± 2.5%, respectively. Meanwhile, ATPS method extracted only 43.66 ± 2.3%
of acetic acid and 73.50 ± 4.5% of butyric acid. Acetic and butyric acids extracted were
28.10 ± 0.9% and 91.92 ± 1.3%, respectively by using solvent extraction method.
Moreover, the mechanisms of adsorption process was analyzes using x-ray fluorescence
(XRF), x-ray diffraction (XRD), fourier-transform infrared (FT-IR) and zeta potential.
The 73.99% of carbon component detected by using XRF analysis and appearance of
amorphous structure in activated carbon after adsorption proses showed that the
adsorption process was occurred. Meanwhile, FT-IR and zeta potential conclude that the
adsorption process of VFAs on the surface of activated carbon was by chemisorptio which was covalent bond. Furthermore, adsorption isotherm for both acetic and butyric
acids fitted Langmuir model with the coefficient of determination value (R2) of 0.9624
and 0.9658, respectively that indicate monolayer adsorption of VFAs on the surface of
activated carbon. The chemisorption bonding was also proved by adsorption kinetics
that showed both acetic and butyric acids fitted pseudo second-order model which the R2
equal to 0.9873 for acetic acid and 0.9978 for butyric acid. The recovery of acetic and
butyric acids from activated carbon were studied in desorption process. Shaker was the
best instrument to be used in desorption process compared to vortex, waterbath sonicator
and probe sonicator. Meanwhile, types of diluent that gave high recovery percentage of
acetic (54%) and butyric (29%) acids were deionized water and ethanol respectively by
using shaker. Multistage desorption process were applied to increase the VFAs
recoveries. Thus, the final recoveries were 89.1% for acetic acid and 67.8% for butyric
acid.
Actions (login required)
 |
View Item |
