Simultaneous removal of nitrate and nitrite using electrocoagulation/floatation (ECF): A new multi-response optimization approach

• Published in: Journal of environmental management 2019-11, Vol.250, p.109489-109489, Article 109489
• Main Authors: Nazlabadi, Ebrahim, Alavi Moghaddam, Mohammad Reza, Karamati-Niaragh, Elnaz
• Format: Article
• Language: English
• Subjects: Electrocoagulation/floatation; Modeling; Nitrate/ nitrite removal; Optimization; Response surface methodology
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2019.109489

This study aims to remove both nitrate and nitrite from wastewater as well as modeling and simultaneous optimizing the electrocoagulation/floatation (ECF) process with 3 responses, namely, the residual nitrate, the residual nitrite and the operating costs; so that all responses meet the standard limitations. For this purpose, 57 experiments designed by the response surface method (RSM) were carried out. The effect of selected variables, including initial pH, current intensity, initial nitrate concentration, number of electrodes, reaction time and their interactions were evaluated. The analysis of variance (ANOVA) confirmed that the predicted equations were in reasonable agreement with the experimental data for three responses. To reach a new multi-response optimization approach, a code was developed in MATLAB software, which was applied to optimize the responses all together. Eight optimized conditions were obtained in accordance with the residual nitrate and the residual nitrite of less than 50 mg/L and 10 mg/L, respectively, and the limited operating costs to 10 ± 0.05 US$/(kg NO3−removed). [Display omitted] •Simultaneous removal of nitrate and nitrite as its by-product using the ECF process.•Applying a new multi-response modeling approach through RSM.•Simultaneous optimization of three responses using a MATLAB self-developed code.•Offering eight optimized results based on the selected constraints in ECF process.