Page 54 - Abstract book - TJSSF-2020

Thailand – Japan Student Science Fair 2020 (TJ-SSF 2020)
“Seeding Innovations through Fostering Thailand – Japan Youth Friendship”

Cellulose-Chitosan Absorbents for Water Treatment

Jiratchaya Karavapong , Sirabhadra Naraballobh
1
1
Advisor: Thanasan Nilsu
1

Kamnoetvidya Science Academy
1

Abstract
Heavy metals in water have become more concerned as a major environmental issue due to its hazardous
effect on humans and other organisms. Cellulose and chitosan biopolymers were chosen as heavy metal
absorbents considering their high potential in decontaminating heavy metal ions in wastewater. A
cellulose-chitosan hydrogel composite was prepared as a biodegradable bio-absorbent through structure
modification and cross-linking. To enhance ion absorbability, the functional groups in cellulose and
chitosan polymers were chemically modified before modeled as hydrogel beads in cross-linking
process. The hydrogel was formed by ionotropic gelation of alginate in CaCl2 solution. In hydrogel
formation, alginate hydrogels from cellulose, carboxymethylated chitosan, and a combination of
cellulose and carboxymethylated chitosan were prepared successfully. Then, the cross-linked hydrogels
were tested for their water and salt retention capability to evaluate salt absorbability. As a result, the
cellulose hydrogel performed the highest ion absorbability, followed by cellulose and
carboxymethylated chitosan hydrogels. Moreover, the heavy metal absorption was carried out with
CuCl2 aqueous solution in various pH conditions (pH 2-6) to represent wastewater. The concentration
of Cu was measured using a colorimetric method. The results revealed that, at pH 4, every type of
2+
hydrogels showed the highest absorption of Cu . In addition, hydrogel beads from carboxymethylated
2+
chitosan and a combination of cellulose and carboxymethylated chitosan could absorb Cu more
2+
efficiently than cellulose hydrogels. The absorption mechanism would be further investigated using
scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR). These
experiments can be concluded that hydrogel beads from modified biopolymers could potentially absorb
heavy metal ions in wastewater.

Keywords: Cellulose, Chitosan, Heavy metal ion, Hydrogel, Cross-linking

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