Laccase based de-inking of mixed office waste and evaluation of its impact on physico-optical properties of recycled fiber

Abstract

The de-inking ability of the crude laccase (benzenediol: oxygen oxidoreductase, EC 1.10.3.2) produced by a white rot fungus Peniophora sp. (NFCCI-2131) was tested using mixed office waste paper. In addition, the impact on physical and optical properties of the de-inked pulp, and the chemical load of the effluent generated during laccase based de-inking process was also analyzed. In the present study, 2.5 U/ml laccase was produced by the fungus under submerged culture conditions. Laccase (10 U/g of air dried pulp) was found to improve the tensile strength of recycled pulp by 1.7-fold, de-inking efficiency by 1.5-fold, opacity by 3.84%, and brightness by 5.83%. Scanning electron microscopy analysis revealed less rupturing of cellulose fibers and increased detachment of ink particles from the surface of the fibers in comparison to chemical de-inking. Fourier-transform infrared spectroscopy analysis of laccase treated pulp revealed degradation of the guaiacyl group and a high degree of deformation in methyl group of lignin. The biochemical and chemical oxygen demand (BOD and COD) were found to be reduced by 52 and 36% respectively, in the effluent generated after crude laccase based de-inking of mixed office waste.

Biodeinking Kertas Koran Bekas menggunakan Ekstrak Kasar Lakase dari Marasmiellus palmivorus

“…Penelitian terkait biodeinking dengan menggunakan enzim telah dilaporkan dan terbukti dapat meningkatkan kualitas optis kertas dari serat sekunder (Virk et al, 2013;Gupta et al, 2015;Hong et al, 2017;Shankar et al, 2018). Oleh karena itu, dalam penelitian ini dilakukan proses biodeinking kertas koran bekas dengan menggunakan ekstrak kasar lakase dari jamur M. palmivorus dengan optimasi perlakuan dosis enzim, waktu biodeinking, dan suhu perlakuan.…”

Comparative Optimization of Cellulase and Laccase Enzymes in Deinking Process of Used Newspapers

“…The preparation of recycled newspaper pulp was using a modified method previously used [21]. In short, recycled newspapers were cut into 2-3 cm 2 sizes.…”

“…After the deinking process, the absorption intensity strengthens, which indicates an increase in the degradation of the aliphatic side chain in the cellulose. The absorption at 1427 cm 1 arose due to the stretching vibration of -CH 3 , indicating that half of the methoxyl groups had disappeared during the deinking process [21].…”

“…The crystallinity index of newspaper samples Usually, the cellulose crystallinity index ranges from 50 -90 %. The higher the crystallinity index, the better the structural composition of the polymer [21].…”

“…Brightness is an intrinsic reflection factor measured at an effective wavelength of 457 nm using a reflectometer [21]. The degree of brightness of newspaper samples is presented in Table 4 and Figure 5 .…”