Desalination by pulsed electrodialysis reversal: Approaching fully closed-loop water systems in wood pulp mills

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:298

Article

Gonzalez-Vogel, Alvaro^1,2  Moltedo, Juan J.¹  Rojas, Orlando J.^2,3 

[1] Bioforest SA, Camino Coronel Km 15, Concepcion, Chile

[2] Aalto Univ, Sch Chem Engn, Dept Bioprod & Biosyst, Espoo, Finland

[3] Univ British Columbia, Bioprod Inst, Dept Chem & Biol Engn Chem & Wood Sci, 2360 East Mall, Vancouver, BC V6T IZ3, Canada

关键词: Electrodialysis reversal;    Kraft process wastewater;    Effluent recirculation;   

DOI  :  10.1016/j.jenvman.2021.113518

来源: Elsevier

【 摘 要 】

A pulsed electrodialysis reversal (pEDR) process is proposed to desalinate spent water after particle removal, biological and chemical coagulation, which are commonly used as a sequence in Kraft pulp mills. pEDR affords closed-loop processing, reducing the need for freshwater intake while maintaining the quality of recirculating process streams. Compared with conventional electrodialysis, pEDR minimizes production losses (from 5 % to 0.6 %), extending the time for hydraulic reversal (from 15 min to at least 2 h). Simultaneously, the conductivity of the effluent is significantly reduced, from 2100 to 200 mu S/cm, reaching a quality similar to the feed water. The operation cost (0.38 US$/m3) is factored in the techno-economic viability of the process water recirculation, which is also demonstrated for its scalability. Additionally, WinGEMS simulation highlights the benefits of installing a pEDR unit, positively impacting mill water under different recirculation rates. Overall, we show remarkable gains in water economy, operation (maintenance and fouling), and quality, which are critical factors in achieving resource sufficiency.

【 授权许可】

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