Comparative Study of Chemical Coagulation and Electrocoagulation for the Treatment of Real Textile Wastewater: Optimization and Operating Cost Estimation

Aicha Gasmi; Soumaya Ibrahimi; Noureddine Elboughdiri; Mohamed Aymen Tekaya; Djamel Ghernaout; Ahmed Hannachi; Abdelhakim Mesloub; Badreddine Ayadi; Lioua Kolsi

doi:10.1021/acsomega.2c01652

Comparative Study of Chemical Coagulation and Electrocoagulation for the Treatment of Real Textile Wastewater: Optimization and Operating Cost Estimation

ACS Omega. 2022 Jun 16;7(26):22456-22476. doi: 10.1021/acsomega.2c01652. eCollection 2022 Jul 5.

Authors

Affiliations

¹ Laboratory of Engineering Processes and Industrial Systems, Chemical Engineering Department, National School of Engineers of Gabes, University of Gabes, Street Omar Ibn El-Khattab, Gabes 6029, Tunisia.
² Mechanical Modeling, Energy and Materials Unit Research (MEM), National School of Engineering of Gabes, Gabes 6029, Tunisia.
³ Chemical Engineering Department, College of Engineering, University of Ha'il, P.O. Box 2440, Ha'il 81441, Saudi Arabia.
⁴ Chemical Engineering Process Department, National School of Engineers Gabes, University of Gabes, Gabes 6029, Tunisia.
⁵ Chemical Engineering Department, Faculty of Engineering, University of Blida, P.O. Box 270, Blida 09000, Algeria.
⁶ Department of Architectural Engineering, College of Engineering, University of Ha'il, P.O. Box 2440, Ha'il 81441, Saudi Arabia.
⁷ Department of Mechanical Engineering, College of Engineering, University of Ha'il, P.O. Box 2440, Ha'il 81441, Saudi Arabia.

Abstract

Pollutants derived from real textile wastewater present a high environmental risk. This work involves the study of the removal of chemical oxygen demand (COD), color, and turbidity from Tunisian real textile wastewater by two different water treatment technologies: chemical coagulation (CC) and electrocoagulation (EC). A comparative study between these two methods was conducted based on the separation performance and operating cost (OC). The effects of different operational parameters including electrolysis time (t), voltage, and pH for EC and the coagulant concentration, initial pH, and time of slow mixing (t _sm) for CC were studied using response surface methodology. The developed quadratic models for the responses were in good agreement with the experimental data. The experiments proved the efficiency of both chemical and electrochemical techniques for the treatment of textile effluent. Indeed, by using EC, the reduction efficiencies of COD, color, and turbidity were 63.05, 99.07, and 96.31%, respectively, under optimal conditions (pH 9, t = 36.26 min, and voltage 4 V). For CC treatment, the achieved removal efficiencies of COD, color, and turbidity were 54.02, 96.21, and 93.7%, respectively, at pH 8.57, a coagulant concentration of 204.75 mg/L, and a t _sm of 28.41 min as optimal operating conditions. The OC obtained for EC and CC was about 0.47 and 0.2 USD/m³, respectively. Even if the OC of the EC process was higher as compared to the CC process, the treated water obtained by EC meets the Tunisian Standards (NT 106.03 and NT 09-14) for textile wastewater discharge into the environment and demonstrates a high potential for its reuse in various industrial activities. EC technology can be integrated into a wastewater management system that ensures a zero liquid discharge of wastewater into the environment.