Abstract:
An increasing use of dyes for product coloring has resulted in a huge volume of
colored water. Casuarina equisetifolia seeds, an eco-friendly plant waste were used to
develop a microwave and chemically treated adsorbent to remove methylene blue
(MB) dye from aqueous solution. This study was conducted to determine the
characteristics of adsorbent and effects of dosage of adsorbent on concentration of
methylene blue dyes removed as well as applicability of Langmuir and Freundlich
isotherms. The characteristics of adsorbent were investigated using scanning electron
microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Brunaeur
Emmet-Teller (BET) surface area analyzer, elemental analyzer and electro kinetic
analyzer (EK.A). Adsorption experiments were performed based on adsorbent dosage
parameter by using batch adsorption method. The Langmuir and Freundlich isotherms
were employed to interpret the adsorption behavior. The adsorption of MB dye on C.
equisetifolia seeds was confirmed by the presence of carboxylic acid and hydroxyl
functional groups based on the FTIR spectrum. Other than that, morphology, surface
area and surface charge analysis also supported the results of methylene blue dye
adsorption. The best adsorbent dosage is 1 gram with 92.4% dye removal.
Experimental data describes the adsorption behavior followed Langmuir isotherm
model. The results imply that C. equisetifolia seeds are a potentially low-cost
adsorbent for treating wastewater containing cationic dyes.
