A new approach to increasing the efficiency of low-pH Fe-electrocoagulation applications
| Autor: | Ori Lahav, Youri Gendel |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Environmental Engineering
Iron Health Toxicology and Mutagenesis medicine.medical_treatment Inorganic chemistry Electrocoagulation law.invention law medicine Environmental Chemistry Electrodes Waste Management and Disposal Titanium Electrolysis Chemistry Environmental engineering Water Hydrogen-Ion Concentration Pollution Anode Oxygen Wastewater Water treatment Sewage treatment Chlorine Low dissolved oxygen Oxidation-Reduction |
| Zdroj: | Journal of Hazardous Materials. 183:596-601 |
| ISSN: | 0304-3894 |
| Popis: | Incomplete oxidation of Fe(II) species released from the anode to Fe(III) may impede iron electrocoagulation processes conducted under low dissolved oxygen and/or pH7 conditions, accompanied by the typically high buffering capacity of wastewater. This paper introduces a new approach to overcome this drawback by applying a second electrochemical cell (Ti/RuO(2) anode and Ti cathode) to be operated in parallel to the electrocoagulation cell. The second unit oxidizes Cl(-) ions invariably present in the water to HOCl, which is capable of oxidizing Fe(II) species at a high rate, irrespective of pH or O(2(aq)) concentration. An electrolytic cell with a Ti/RuO(2) anode and Ti cathode was shown to successively operate in parallel to a sacrificial electrocoagulation cell (Fe anode and Ti cathode) to attain complete Fe(II) conversion to Fe(III) under low-pH conditions, in which, in the absence of the 2nd cell, unwanted Fe(II) species would have dominated the dissolved iron species. Current efficiency for Cl(2) production was 12.4% and 45.7% at 200 and 1000 mg Cl/l, respectively. Under three practical conditions (pH 6, [Cl(-)]=200 mg/l; pH 6, [Cl(-)]=400 mg/l; pH 5, [Cl(-)]=600 mg/l) the power demand of the combined system was 25.29, 12.7 and 8.1 kWh/kg Fe(III)(produced), respectively, suggesting that the presented approach is competitive at [Cl(-)]∼600 mg/l. |
| Databáze: | OpenAIRE |
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