2.3. Analysis
COD analysis was conducted by reactor digestion HACH method 8000, which was approved by
USEPA as per Federal Register, April 21, 1980, 45 (78) 26811-26812, using high range vial (0-1500
mg/L). HACH methods are described in detail in the HACH' Odyssey DR/2400 spectrophotometer manual.
Concentration of oxidants were analyzed by iodometric titration [10].
2.4. Experiments
Oxidation by hydrogen peroxide and calcium hypochlorite was carried out in 250 mL agitated reactor
contained 200 mL solution at 30 ºC. Ozone was produced from a 1VTTL-Ozomax ozone generator with
maximum capacity of 10 gr h-1 utilizing pure oxygen gas feed. Ozonation of samples was carried out
using a glass reactor with a working volume of 1800 mL equipped with a teflon diffuser. 1.3 liters of
sample was added into the glass reactor agitated at 100 rpm and 30 ºC Ozone gas was supplied at
concentration of 6 Gh-1 by flowing of 0.09 Nm3H-1 oxygen. The performance of chemical oxidation was
evaluated based on chemical oxygen demand (COD) removal.