Tertiary treatment of wastewater by coupling anodic oxidation processes using solar energy and the coagulation–flocculation processes

Abstract

Tunisia has been compelled to use treated wastewater in irrigation due continuous increase in demand. Since 1999, the Edissa perimeter in Gabes, Tunisia, has been watered with treated waste-water (TWW) from the Gabes sewage treatment plant. However, it is imperative to assess the quality of this water source. The current study aims to accomplish tertiary treatment of TWW of Gabes sewage treatment plant using alternate processes by combining anodic oxidation processes using solar energy with coagulation–flocculation. Treatment under optimal conditions has shown that the combination of two processes was effective in achieving a reduction in pollution with satisfactory results in terms of elimination of the chemical oxygen demand (100%), total organic carbon (100%), biochemical oxygen demand (86%), Cl–, NH4+, NO3–, and PO43– with abatement rates of (100%). The concentration of heavy metals including (Ni, AI, Cu, Pb, Zn, Fe, Cr, Cd) have been reduced from 45% for Fe to 95% for Ni, and complete elimination of germs.