Electroflotation enables treatment of effluents generated during pyrolytic biomass revalorization

Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L−1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed.

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“…The MSD transmission-line temperature was set to 280 °C. The specific operations and procedures are described in a previous paper [ 45 ].…”

Section: Methodsmentioning

confidence: 99%

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency

Liu

Deng

Liang

et al. 2022

IJMS

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“…These gases emerge simultaneously from the electrode surface as electrolytic bubbles [12]. The electroflotation process has been applied in (i) solid-liquid of colloidal particles [13][14][15][16] separation, (ii) microalgae [17], (iii) oil [18,19], (iv) mineral recovery [15,[20][21][22], (v) microplastic [23,24], and (vi) wastewater [25][26][27][28] among others [29,30].…”

Section: Introductionmentioning

confidence: 99%

Corrosion of Titanium Electrode Used for Solar Saline Electroflotation

Madrid,

Arancibia-Bravo,

Cisterna

et al. 2023

Materials

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The solar electroflotation (EF) processes using saline electrolytes are today one of the great challenges for the development of electrochemical devices, due to the corrosion problems that are generated during the operation by being in permanent contact with Cl− ions. This manuscript discloses the corrosion behavior of titanium electrodes using a superposition model based on mixed potential theory and the evaluation of the superficial performance of the Ti electrodes operated to 4 V/SHE solar electroflotation in contact with a solution of 0.5 M NaCl. Additionally provided is an electrochemical analysis of Ti electrodes regarding HER, ORR, OER, and CER that occur during the solar saline EF process. The non-linear superposition model by mixed potential theory gives electrochemical and corrosion parameters that complement the information published in scientific journals, the corrosion current density and corrosion potential in these conditions is 0.069 A/m2 and −7.27 mV, respectively. The formation of TiO2 and TiOCl on the anode electrode was visualized, resulting in a reduction of its weight loss of the anode electrode.

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Degradation of the antibiotic ciprofloxacin in urine by electrochemical oxidation with a DSA anode

Felisardo,

Brillas,

Romanholo Ferreira

et al. 2023

Chemosphere

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Electroflotation enables treatment of effluents generated during pyrolytic biomass revalorization

Cited by 7 publications

References 44 publications

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency

Corrosion of Titanium Electrode Used for Solar Saline Electroflotation

Degradation of the antibiotic ciprofloxacin in urine by electrochemical oxidation with a DSA anode

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