TITLE:
Application of Anodic Oxidation with Graphite Electrodes in Pretreated Leachates
AUTHORS:
T. J. Sánchez-Sánchez, H. A. Nájera-Aguilar, R. F. Gutiérrez-Hernández, C. M. García-Lara, J. A. Araiza-Aguilar, J. A. Bautista-Ramírez, J. H. Castañón-González
KEYWORDS:
Anodic Oxidation, Graphite Electrodes, Advanced Oxidation Processes
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.10 No.3,
March
11,
2020
ABSTRACT: Currently, landfills are the main method used for the final disposal of
urban solid waste. The degradation processes that waste goes through in these
sites, alongside rainwater that percolates through them, generate highly
polluting liquids (leachate). In the treatment of leachate, advanced oxidation
processes (AOP) can significantly reduce the concentrations of different
pollutants. Due to the high documented potential around AOPs, in this study,
the effectiveness of anodic oxidation in the removal of the remaining organic
load in leachates pretreated in a biological system was evaluated. Graphite
electrodes were used as anode and cathode. The efficiency of anodic oxidation,
in terms of the removal of chemical oxygen demand (COD) and color, was
evaluated under different current densities (7, 12, 17 and 22 mA/cm2)
and pH values (3, 4.5 and 6). Under the best conditions found (22 mA/cm2 and pH of 6) and with an oxidation time of 5 hours, a maximum removal of 68% in
COD and 91% in color was achieved, which represented a quality in the final
effluent of 271 mg/L and 151 Pt-Co in COD and color, respectively. Therefore,
considering that graphite is an economic and widely available material, the
results obtained show anodic oxidation, with the use of graphite electrodes, as
a technically viable alternative as a final purification stage for pretreated
leachates.