{"title":"Sequential electro-coagulation and electro-Fenton processes for the treatment of textile wastewater.","authors":"Palak Agarwal, Vikas K Sangal, Sanjay Mathur","doi":"10.1002/wer.11118","DOIUrl":null,"url":null,"abstract":"<p><p>Textile wastewater, laden with persistent dyes and non-biodegradable organics, poses a challenge for treatment in common effluent treatment plants (CETPs) using conventional methods. Pre-treatment of textile effluents is essential to ensure compatibility with CETPs. The present study employed three-dimensional (3D) aluminum and graphite electrodes for a sequential electro-coagulation and electro-Fenton (EC + EF) process. An experimental plan of 25 experiments was constructed using Taguchi method. The combination resulted in high removal efficiencies: 99.91% for color, 93.20% for chemical oxygen demand (COD), and 91.75% for total organic carbon (TOC) for the operating parameters; for EC, current density (J): 20 mA/cm<sup>2</sup>, time (t): 45 min, speed of rotation (N): 55 rpm; and for EF, current density (J): 25 mA/cm<sup>2</sup>, time (t): 50 min, iron concentration: 40 mg/L. Post-treatment, the wastewater exhibited an enhanced biodegradability index of 0.875, rendering it suitable for CETPs. There was an increase of 11% in the total energy consumption when energy spent during rotation and aeration at the time of EC and EF, respectively, were considered. This energy increases the cost and is not accounted for, in previous research. The energy consumption in kWh per g of COD removed at optimum condition for the hybrid treatment was 0.0314, which is lower than the energy consumption by other electrochemical processes employing plate electrodes. This indicates that 3D electrodes are more energy efficient than plate electrodes. PRACTITIONER POINTS: Hybrid electrochemical processes can be used as pre-treatment method for textile effluents. Three-dimensional electrodes improve removal rates with lower energy consumption. Significant color, COD, and TOC abatement were noted post-hybrid treatment of textile wastewater. Biodegradability of the textile effluent improves after the hybrid treatment.</p>","PeriodicalId":23621,"journal":{"name":"Water Environment Research","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Environment Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1002/wer.11118","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Textile wastewater, laden with persistent dyes and non-biodegradable organics, poses a challenge for treatment in common effluent treatment plants (CETPs) using conventional methods. Pre-treatment of textile effluents is essential to ensure compatibility with CETPs. The present study employed three-dimensional (3D) aluminum and graphite electrodes for a sequential electro-coagulation and electro-Fenton (EC + EF) process. An experimental plan of 25 experiments was constructed using Taguchi method. The combination resulted in high removal efficiencies: 99.91% for color, 93.20% for chemical oxygen demand (COD), and 91.75% for total organic carbon (TOC) for the operating parameters; for EC, current density (J): 20 mA/cm2, time (t): 45 min, speed of rotation (N): 55 rpm; and for EF, current density (J): 25 mA/cm2, time (t): 50 min, iron concentration: 40 mg/L. Post-treatment, the wastewater exhibited an enhanced biodegradability index of 0.875, rendering it suitable for CETPs. There was an increase of 11% in the total energy consumption when energy spent during rotation and aeration at the time of EC and EF, respectively, were considered. This energy increases the cost and is not accounted for, in previous research. The energy consumption in kWh per g of COD removed at optimum condition for the hybrid treatment was 0.0314, which is lower than the energy consumption by other electrochemical processes employing plate electrodes. This indicates that 3D electrodes are more energy efficient than plate electrodes. PRACTITIONER POINTS: Hybrid electrochemical processes can be used as pre-treatment method for textile effluents. Three-dimensional electrodes improve removal rates with lower energy consumption. Significant color, COD, and TOC abatement were noted post-hybrid treatment of textile wastewater. Biodegradability of the textile effluent improves after the hybrid treatment.
期刊介绍:
Published since 1928, Water Environment Research (WER) is an international multidisciplinary water resource management journal for the dissemination of fundamental and applied research in all scientific and technical areas related to water quality and resource recovery. WER''s goal is to foster communication and interdisciplinary research between water sciences and related fields such as environmental toxicology, agriculture, public and occupational health, microbiology, and ecology. In addition to original research articles, short communications, case studies, reviews, and perspectives are encouraged.