COMPARISON OF ELECTROCOAGULATION COUPLED WITH SYNTHETIC ZEOLITE,
ULTRASOUND AND TWO STEPS ELECTROCOAGULATION

Due to the very complex composition of leachate wastewater, combining two or more physical, chemical,
or biological processes, carried out simultaneously or sequentially, is highly needed in order to obtain
effluent suitable for further discharge into sewage. In this paper, electrocoagulation coupled with
synthetic zeolite (EC-NaX), electrocoagulation coupled with ultrasound (EC-US), and two steps
electrocoagulation (EC-1st and EC-2nd) were tested for compost leachate treatment, with very high initial
organic loading and acidic pH. The comparison of each process was done in regard to the following
parameters: pH, electrical conductivity and temperature change, removal percentage of chemical oxygen
demand (COD), turbidity, total solids change, settling ability, and electrode consumption. Results highlight
the EC-NaX as the best option for the treatment of compost leachate, due to the highest removal
percentage of COD (51.91%), satisfactory removal percentage of turbidity (97%), good settling abilities, and
lowest electrode consumption. However, the final COD values in the effluent are still significantly high
for further discharge into sewage systems, thus additional treatment needs to be applied. Also, the final
acidic pH, high values of electrical conductivity, and high temperature of effluent need to be solved in
further treatment steps.