Dye wastewater currently damages both human health and aquatic ecosystem, so to reduce its negative effects and promote
sustainable development, this study optimizes cellulose extraction process from coconut coir pith via employing response
surface methodology combined with Design Expert software (version 11.0.1.0, Copyright©2017, Stat-Ese Inc., USA). The
recovered cellulose after alkalizing and decolorizing process is applied to assess its adsorption capability of methylene blue
from water. Methylene blue adsorption capacity is evaluated based on operating factors: pH, contact time, methylene blue
initial concentration and cellulose mass. The success of cellulose extraction process is established by Fourier-transform
infrared spectroscopy, X-Ray Diffraction and Thermogravimetric analysis. The recovered cellulose particles have a high
crystallinity index of 46.39% and high purity of 35.63% with an average diameter of 344 μm with a specific surface area of
3.303 m2.
g−1, a porous structure with a pore diameter of 34.952Å and pHpzc
of 6.14. Under optimal adsorption conditions,
methylene blue adsorption efficiency of 99.22% is achieved, and the process is favorable, reversible, and monolayer adsorption.
The adsorption in this work is in good agreement with pseudo-second-order kinetic model and physical adsorption is
the main adsorption mechanism. Importantly, the recovered cellulose has a significantly high adsorption capacity of 145.81
mg.g−1 after seven continuous using times. These findings propose that cellulose can recover from coconut coir pith byproduct
and holds a highly potential on dye removal from aqueous solution.