Abstract:
This work aimed at studying the photochemical treatment of a landfill leachate using ultraviolet light, hydrogen peroxide, and ferrous or ferric ions, in a batch recycle photoreactor. The
effect of inorganic carbon presence, pH, initial H2O2 amount (0–9990 mg L-1) as well as Fe
(II) (200–600 ppm) and Fe(III) (300–700 ppm) concentrations on the total carbon removal
and color change was studied. Prior to the photochemical treatment, a pretreatment process
was applied; inorganic nitrogen and inorganic carbon were removed by means of air stripping and initial pH regulation, respectively. The leachate sent subsequently for photochemical treatment was free of inorganic carbon and contained only organic carbon with
concentration 1200±100 mg L-1 at pH 5.1–5.3. The most favorable concentrations of H2O2
and ferric ions for carbon removal were 6660 mg L-1 and 400 ppm, respectively. Adjusting
the initial pH value in the range of 2.2–5.3 had a significant effect on the organic carbon
removal. The photo-Fenton-like process was more advantageous than the photo-Fenton
one for leachate treatment. By applying the most favorable operating conditions, 88.7%
removal of total organic carbon, 100% removal of total inorganic carbon, 96.5% removal of
total nitrogen, and 98.2% color removal were achieved.
