Reuse of Textile Dyeing Wastewater Treated by Electrooxidation

Water

Ana Lopes¹  Maria João Nunes¹  Annabel Fernandes¹  Maria José Pacheco¹  Cláudia Pinto¹  Ana Baía¹  Lurdes Ciríaco¹ 

[1] Fiber Materials and Environmental Technologies (FibEnTech-UBI), Universidade da Beira Interior, R. Marquês de D’Ávila e Bolama, 6201-001 Covilhã, Portugal;

关键词: wool dyeing wastewater;    electrooxidation;    boron-doped diamond;    ecotoxicity;    Daphnia magna;    salts recovery;   

DOI  :  10.3390/w14071084

来源: DOAJ

【 摘 要 】

Wastewater reuse has been addressed to promote the sustainable water utilization in textile industry. However, conventional technologies are unable to deliver treated wastewater with the quality required for reuse, mainly due to the presence of dyes and high salinity. In this work, the feasibility of electrooxidation, using a boron-doped diamond anode, to provide treated textile dyeing wastewater (TDW) with the quality required for reuse, and with complete recovery of salts, was evaluated. The influence of the applied current density on the quality of treated TDW and on the consecutive reuse in new dyeing baths was studied. The ecotoxicological evaluation of the process towards Daphnia magna was performed. After 10 h of electrooxidation at 60 and 100 mA cm⁻², discolorized treated TDW, with chemical oxygen demand below 200 (moderate-quality) and 50 mg L⁻¹ (high-quality), respectively, was obtained. Salt content was unchanged in both treatment conditions, enabling the consecutive reuse without any salt addition. For the two reuse cycles performed, both treated samples led to dyed fabrics in compliance with the most restrictive controls, showing that an effective consecutive reuse can be achieved with a moderate-quality water. Besides the water reuse and complete salts saving, electrooxidation accomplished an ecotoxicity reduction up to 18.6-fold, allowing TDW reuse without severe ecotoxicity accumulation.

【 授权许可】

Unknown