Phương pháp điện hoá cho Sự xuống cấp của chất ô nhiễm hữu cơ trong Media dịch nước Trong 30 năm qua, một lượng lớn các kỹ thuật điện cho tiêu hủy độc hại và vật liệu chịu lửa (tức là, nonbiodegradable) các chất ô nhiễm hữu cơ xử lý nước thải đã được đề xuất và phát triển. Chỉ có một vài phương pháp thông thường có liên quan đến điện trực tiếp các chất ô nhiễm tại các điện cực. Quá trình này có thể xảy ra là do một phản ứng điện tử để chuyển giao trực tiếp. | 6 Electrochemical Methods for Degradation of Organic Pollutants in Aqueous Media Enric Brillas and Pere-Lluis Cabot Universitat de Barcelona Barcelona Spain Juan Casado Carburos Metálicos . Barcelona Spain I. INTRODUCTION In the last 30 years a large variety of electrochemical techniques for the destruction of toxic and refractory . nonbiodegradable organic pollutants for wastewater treatment have been proposed and developed. Only a few conventional methods are related to the direct electrolysis of pollutants at the electrode. This process can occur either by a direct electron transfer reaction to reduction or from oxidation the undesired organic or by a chemical reaction of the pollutant with previously electrogenerated species which remain adsorbed at the electrode surface. Most electrochemical methods are based on indirect or mediated electrolysis in which the target pollutant is removed in the solution by active species produced reversibly or irreversibly at the electrode. The two types of procedures are contrasted in Fig. 1. The use of electrochemical techniques offers the following distinctive advantages for wastewater treatment 1 1. Environmental compatibility. The main reactant is the electron which is a clean reagent. 2. Versatility. Electrolytic treatments can deal with solid liquid or gaseous pollutants to generate neutral positively or negatively Copyright 2003 by Marcel Dekker Inc. All Rights Reserved. Figure 1 Schemes for different electrochemical treatments of organic pollutants. a Direct electrolysis by anodic oxidation in which the pollutant reacts at the electrode surface with adsorbed OH produced from water oxidation at a high O2-overpotential anode. b Indirect electrolysis where the pollutant reacts in the solution with an irreversibly electrogenerated reagent B produced from the oxidation of inactive B at the anode. charged inorganic or organic products also inducing the production of precipitates gaseous species pH changes etc. In .
