Effect of humic substances on the Fenton treatment of wastewater at acidic and neutral pH.
This paper describes results of treatability studies of the effect of humic substances (humate, HS, at the concentration 500-5000 mg l-1) on the Fenton (Fe2+/H2O2) treatment of industrial wastewater at pH 3.5 and 7.0. Without humate, the removal of all contaminants was significantly higher at pH 3.5 than at pH 7. At pH 7.0, the removal of all compounds in the presence of HS (3000 mg l-1) was comparable to that at pH 3.5 without HS. At pH 3.5, humate had no effect on the removal of arsenic, thiocyanate and cyanide, but the removal of all organic compounds (phenol, 2,4-dimethylphenol, benzene, toluene, o-xylene, m- & p-xylene and dichloromethane) was significantly inhibited. Mechanisms of the processes are discussed. It is suggested that, in the presence of HS, acidification of the treated wastewater may not only be unnecessary but it can even hinder the degradation of organic pollutants.
Lipczynska-Kochany
Ewa
E
Environmental Consultant, 30 Elm Drive East, Suite 918, Mississauga, ON, Canada L5A 4C3.
Kochany
Jan
J
D005296:Ferrous Compounds / Q000737:chemistry; D006812:Humic Substances; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods
C045076:Fenton's reagent; D005296:Ferrous Compounds; D006812:Humic Substances; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; C020748:ferrous sulfate; D006861:Hydrogen Peroxide; D007501:Iron