Journal of
Environmental Chemistry and Ecotoxicology

  • Abbreviation: J. Environ. Chem. Ecotoxicol.
  • Language: English
  • ISSN: 2141-226X
  • DOI: 10.5897/JECE
  • Start Year: 2009
  • Published Articles: 198

Full Length Research Paper

Removal of refractory organic and inorganic load from gray ship wastewater by the electro-oxidation process

Kouame Kouakou Benoit
  • Kouame Kouakou Benoit
  • Laboratory of Industrial Processes, Synthesis, Environment and New Energies, National Polytechnic Institute Félix Houphouët Boigny, Yamoussoukro, Côte d'Ivoire.
  • Google Scholar
Gueu Soumahoro
  • Gueu Soumahoro
  • Laboratory of Industrial Processes, Synthesis, Environment and New Energies, National Polytechnic Institute Félix Houphouët Boigny, Yamoussoukro, Côte d'Ivoire.
  • Google Scholar
Briton bi Gouesse Henri
  • Briton bi Gouesse Henri
  • Laboratory of Industrial Processes, Synthesis, Environment and New Energies, National Polytechnic Institute Félix Houphouët Boigny, Yamoussoukro, Côte d'Ivoire.
  • Google Scholar


  •  Received: 21 June 2024
  •  Accepted: 25 September 2024
  •  Published: 30 November 2024

Abstract

In this work, electro-oxidation which is one of the innovative and efficient processes was used to treat gray and fatty wastewater (oil residues) from ships. These wastewaters contain heavy metals and persistent organic pollutants that damage the marine environment, contaminate the food chain, and harm marine life. This project aimed to apply the electro-oxidation process for the treatment of gray wastewater from ships heavily loaded with COD (1310.4 mgO2/L), TOC (375 mg/L of TOC), lead (3.13), Zn (7.91), and turb (709.5 NTU) in order to comply with sea discharge standards. After the characterization of the effluent, the optimal conditions and the effects of the parameters (current intensity, electrolysis time, and concentration of the electrolyte) made it possible to monitor the degradation (λmax = 490 nm) of the effluent on the one hand as a function of the intensity of the current and on the other hand as a function of the concentration of the electrolyte. This optimization of the current intensity (1.25 A) and the concentration of the electrolyte (2 g/L) made it possible to obtain a respective reduction rate of 99.33, 70, and 67% for the turbidity, COD, and TOC after 6 h of electrolysis. Under the same conditions, a high reduction rate for metals such as Zn (84.11%), Hg (63.31%), and Ag (58.23%) was observed. A relatively low reduction rate was observed with Pb (30.1%). As for Cd and Se, they remained quantitatively in solution. This process made it possible to simultaneously eliminate the organic and mineral load at a satisfactory rate.

Key words: Advanced oxidation processes, organic load, effluent treatment, residual hydrocarbons.