Original scientific paper
https://doi.org/10.5599/jese.2052
Simultaneous phosphates and nitrates removal from waste-waters by electrochemical process: Techno-economical assessment through response surface methodology
Judicaël Ano
; Laboratoire des Procédés Industriels de Synthèse, de l’Environnement et des Energies Nouvelles (LAPISEN), Institut National Polytechnique Félix Houphouët-Boigny, BP 1093, Yamoussoukro, Côte d’Ivoire
*
Bi Gouessé Henri Briton
; Laboratoire des Procédés Industriels de Synthèse, de l’Environnement et des Energies Nouvelles (LAPISEN), Institut National Polytechnique Félix Houphouët-Boigny, BP 1093, Yamoussoukro, Côte d’Ivoire
Alain Stéphane Assémian
; Laboratoire de Thermodynamique et de Physico-chimie du Milieu (LTPCM), UFR-SFA, Université Nangui-Abrogoua, 02 BP 801 Abidjan 01, Côte d’Ivoire
Patrick Drogui
; Institut National de la Recherche Scientifique (INRS Eau Terre et Environnement), Université du Québec, 490 rue de la Couronne, Québec City, Canada
Kouassi Benjamin Yao
; Laboratoire des Procédés Industriels de Synthèse, de l’Environnement et des Energies Nouvelles (LAPISEN), Institut National Polytechnique Félix Houphouët-Boigny, BP 1093, Yamoussoukro, Côte d’Ivoire
Kopoin Adouby
; Laboratoire des Procédés Industriels de Synthèse, de l’Environnement et des Energies Nouvelles (LAPISEN), Institut National Polytechnique Félix Houphouët-Boigny, BP 1093, Yamoussoukro, Côte d’Ivoire
* Corresponding author.
Abstract
In this study, a new multiobjective optimization of the simultaneous removal of phosphates and nitrates by electrocoagulation was studied using the Box-Behnken design. Ten aluminium electrodes, connected in a monopolar configuration in a batch reactor, were immersed in synthetic wastewater and then in real wastewater. The optimal conditions and the effects of parameters (current intensity, electrolysis time and initial pH) on phosphate and nitrate removal, the formation of by-products, and the operating cost were assessed in the case of synthetic wastewater. This optimization allowed to eliminate 89.21 % of phosphates, 69.06 % of nitrates with an operating cost of 3.44 USD m-3 against 13.67 mg L-1 of ammonium generated. Optimal conditions applied to real domestic wastewater made it possible to remove 93 % of phosphates and 90.3 % of nitrates with an ammonium residual of 30.9 mg L-1. The addition of sodium chloride reduced the residual ammonium content to 2.95 mg L-1. Further, XRD analysis of the sludge showed poor crystal structure and the FTIR spectrum suggested that the phosphate is removed by adsorption and co-precipitation.
Keywords
Electrocoagulation; monopolar configuration; phosphates; nitrates; optimization
Hrčak ID:
311033
URI
Publication date:
7.12.2023.
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