Assessment of wastes recycling for deinking purposes in ozone assisted green process

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RESEARCH ARTICLE

Assessment of wastes recycling for deinking purposes in ozone assisted green process Pegah Amiri 1 & Jamshid Behin 1 Received: 24 July 2019 / Accepted: 16 March 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract This study investigates techno-economic aspects of wastepaper recycling to optimize process efficiency and operating cost. The deinking was carried out using pulping followed by froth flotation. The development of a waste management process was achieved employing refinery wastewater to provide chemical reagents in pulping. Ozone was also used as a gas media in flotation to improve brightness and number of ink-spot and to reduce chemical oxygen demand (COD) simultaneously. An enhancement in the brightness was observed from 50.1 to 64.1% ISO that was superior to the brightness of virgin newspaper before printing (61.0% ISO). It was equivalent to a reduction of 55% (from > 100,000 to 45,058) in number of ink-spot. The quality of flotation effluent was assessed by measuring the COD and phthalocyanine concentration. The COD reduction of 67% (from 3250 to 1072 mg/L) and phthalocyanine reduction of 85% (from 2 to 0.3 mg/L) were achieved after 30 min ozonation. According to the obtained results, approximately 67% of the direct (variable) cost reduced while the wastewater was used in pulping because of saving NaOH and water consumption. Associating the refinery and paper recycling wastewater treatment units, while taking into account the environmental and economic benefits of ozone, results in a quality paper and significantly preserves the environment. Keywords Wastepaper recycling . Wastewater minimization . Ozone flotation . Deinking performance . COD removal

Introduction Recycling of wastepaper is augmenting around the world and significantly contributes to a sustainable environment. Wastepaper that is recovered and then reused in its original form requires a managed-recovery process where pollution and damage should be minimized. The deinking of fibers is a prominent step in wastepaper recycling. The inks may be Highlights • Wastewater and ozone were used for paper’s recycling to minimize environmental issues and operating cost. • Phthalocyanine as a hazardous component of wastewater was oxidized by ozone in flotation stage. • The brightness of deinked paper was more than that of virgin unprinted paper using Air lift reactor. • Ozone flotation is an efficient method for considerable reduction of COD from recycling paper mill wastewaters Responsible editor: Vítor Pais Vilar * Jamshid Behin [email protected] 1

Faculty of Petroleum and Chemical Engineering, Razi University, Kermanshah, Iran

removed using chemical process and mechanical separation, such as pulping, washing, and flotation. The current chemical deinking processes are cost-ineffective due to considerable chemicals and energy that eventually leads in harmful effluents (Tsatsis et al. 2017, 2019). Deinking mainly consists of two fundamental operating processes: (i) the pulping which includes the separation of