Investigation into the Ozone Reactivity during the O3/O2 Flotation of Recovered Cellulosic Fiber: Does Ozone Affect the Papermaking Properties of Fibers?. (4th May 2021)

• Record Type: Journal Article
• Authors: Ghorbel, A.; Marlin, N.; Aurousseau, M.; Boyer, A.
• Is Part Of: Ozone: science and engineering. Volume 43:Number 3(2021)
• Page Start: 228
• Page End: 238
• Publication Date: 2021-05-04
• Subjects: Ozone -- flotation -- wastewater Treatment -- recovered lignocellulosic fibers -- fiber papermaking ability -- deinking -- separation process; Ozone -- Periodicals; 665.89
• DOI: 10.1080/01919512.2020.1780904
• Languages: English
• ISSNs: 0191-9512

Abstract

ABSTRACT: The ozone reactive flotation for deinking recovered cellulosic fibers, recently developed at lab scale, showed interesting results in terms of fiber yield and effluent pollution reduction with classical recovered fibers furnishes made of old magazines and old newspapers. However, deinked pulp yellowing occurred. To further develop the ozone-based deinking process, a deeper investigation was conducted to evaluate the effect of ozone reactivity with the cellulosic fibers, and with soluble contaminants originating from the recovered lignocellulosic fibers. For that purpose, flotation trials with air or ozone/oxygen as the gas flow were conducted on model recovered fiber pulps, free of ink particles and contaminants. Two models have been studied, the first containing 100% bleached Kraft pulp and the second one a mixture of 90% bleached Kraft pulp and 10% unbleached thermomechanical pulp to simulate wood-free lignocellulosic fibers furnishes. Moreover, flotation trials were carried out using tap water to submit only cellulosic fiber to the action of ozone and also using industrial model process water containing classical recovered paper contaminants to evaluate the effect of ozone reactivity with soluble species. It has been shown that the deinked pulp brightness increased when ozone was applied to the flotation of wood-free pulp models. Ozone did not impact the deinked pulp strength properties. These results confirmed that ozone reacts preferentially with soluble contaminants, as the deinked pulp strength properties were preserved, which is driving the strong reduction of effluent soluble COD. Analysis of O3 consumption revealed that ozone self-decomposition into water prevailed as well as the reaction with soluble contaminants or water components. In conclusion, reactive ozone-based flotation appears to be a promising green and efficient deinking process for wood-free recovered lignocellulosic fiber recycling. Abbreviations : ONP: old newspaper; OMG: old magazine; MOW: mixed office waste; ERIC: residual ink concentration; NTP: normal conditions of temperature and pressure.