Study on Reuse of Coconut Fiber Chemical Retting Bath. Part II---Recovery and Characterization of Lignin

Study aimed at recovery of lignin from the reused residual liquor of chemical retting bath of coconut fiber caused by partial delignification to make it soft. The lignin of 8.9% was obtained after recovery (maintaining pH 2.0 for 1 h at ambient temperature) and further purification. Extracted lignin is characterized through FTIR, TGA and particle size analysis. FTIR showed absence of polysaccharides in purified lignin. TGA indicates presence of higher methyl-aryl ether groups than aromatic groups in lignin of coconut fibre. Analysis reveals about 91% of particles in the rage of 1–500 µm, which shows its good dispersiblity in fluid. Recovery of lignin associated with two benefits i.e., diversified use of extracted pure lignin and reduction of organic load of the waste liquor to make it suitable for discharge.