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.

中文翻译：

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回收纤维素纤维的O3 / O2浮选过程中的臭氧反应性研究：臭氧是否会影响纤维的造纸性能？

最近在实验室规模上开发的用于使回收的纤维素纤维脱墨的臭氧反应浮选法，在用旧杂志和旧报纸制成的经典回收纤维配料中，在纤维产量和减少废水污染方面显示出有趣的结果。但是，发生脱墨的纸浆变黄。为了进一步发展基于臭氧的脱墨工艺，进行了更深入的研究，以评估臭氧与纤维素纤维以及与回收的木质纤维素纤维来源的可溶性污染物的反应性。为此目的，在模型回收的纤维浆中进行了以空气或臭氧/氧气作为气流的浮选试验，该浆没有油墨颗粒和污染物。研究了两个模型，第一个包含100％漂白的牛皮纸浆，第二个包含90％的漂白牛皮纸浆和10％的未漂白热机械浆的混合物，以模拟不含木材的木质纤维素纤维配料。此外，进行浮选试验时使用自来水使纤维素纤维仅受臭氧作用，还使用含有经典回收纸污染物的工业模型工艺用水来评估臭氧对可溶性物质的反应性。

已经显示，当将臭氧应用于无木浆模型的浮选时，脱墨浆的亮度增加。臭氧不影响脱墨纸浆强度性能。这些结果证实，臭氧可以优先与可溶性污染物发生反应，因为脱墨后的纸浆强度特性得以保留，这推动了废水中可溶性COD的大幅降低。对O ₃消耗量的分析表明，臭氧会自分解为水，并且会与可溶性污染物或水成分发生反应。总之，基于臭氧的反应浮选似乎是一种有前途的绿色高效脱墨工艺，可用于无木材回收的木质纤维素纤维回收。

缩略语

ONP：旧报纸；OMG：旧杂志；MOW：混合办公室废物；ERIC：剩余墨水浓度；NTP：温度和压力的正常条件。