Cellulase-assisted deinking approach for the recycling of mixed office waste papers and its quality improvement

Abstract

This study involves the evaluation of the potential of commercial cellulase enzyme for the deinking of mixed office waste paper. The pH and temperature optima for the enzyme were 6.0 and 50°C. Enzyme dose and reaction time for the deinking process were optimized. An optimum dose of 300 g/t and reaction time of 90 min for commercial cellulase enzyme significantly improved deinking efficiency (79.3%) than the control set (59.4%) and chemical deinking (75.7%). Strength properties (except tear index) like tensile index, breaking length, burst factor and double fold were improved at optimized conditions. Cleanliness of pulp in terms of dirt and specks contents was also improved up to a significant level after cellulase treatment. Thus, it was concluded that commercial cellulase enzyme-based deinking was better than chemical deinking of mixed office waste in terms of improved pulp and paper quality.

Surface characterization of pulp fiber from mixed old newspaper and magazine deinked-pulp with combined cellulase and laccase-violuric acid system (LVS)

“…Cellulase enzyme facilitates surface micro-brillation of bers contributing towards higher inter-ber bonding due to exposure of more hydroxyl groups (Bajpai, 2010;Pathak et al, 2022). In the C 2 L 1 sequence compared to C 1 L 1 , due to the longer duration of the treatment, better strength characteristics have been observed, which can be due to the increase of inter-ber bonding and the further development of surface brillation.…”

“…In recent years, the continuous demand for pulp and paper bers caused the paper industry to utilize secondary bers as an alternative source of lignocellulosic bers (Pathak et al, 2015(Pathak et al, , 2022. Use of recycled bers in the paper industry plays a substantial role as a substitute for virgin pulp.…”

“…The process with low detrimental environmental effects and energy consumption, reduction or elimination of waste, and energy savings are the most common goals using biotechnology during pulp and paper making (Sango et al, 2018;Kumar and Dutt, 2021;Dixit et al, 2022). Ink particles detachment is done from the ber surface during recycling process which includes re-pulping, otation, washing, screening, centrifugal separation or bleaching processes depending on ink particle size, shape and density (Gubitz et al, 1998;Kumar et al, 2018;Biswas et al, 2019;Pathak et al, 2022).…”