Removal of textile dyeing materials from contaminated soils by electrooxidations

Textile dyestuffs are used in many sectors. Due to its high soluble dyes, rich bright color content and ease of application, it is considered suitable for textile dyeing in many respects. Large amounts of water, synthetic dyes, chemicals with different properties are used in different production stages of the textile industry, and as a result of the discharge of wastewater from production activities to the receiving environment, it reaches aquatic ecosystems and soil. Some of the waste dyes in the discharge environment reduce the light transmittance, prevent photosynthesis activities, and cause eutrophication. In addition, the presence of toxic and mutagenic dyestuffs in water bodies negatively affects aquatic life. In addition, some of the dyestuffs mix with the soil and cause pollution. Many different methods are used in the treatment of contaminated soils. Today, electrochemical technologies are widely used in laboratory and pilot scale to remove contaminants. Boron-doped diamond (BDD) electrodes are considered efficient materials for natural and synthetic pollutant removal in aqueous media due to their superior properties such as fast electron transfer rates for soluble redox systems and a wide electrochemical potential window for oxidation reactions. Although the removal of dyestuffs from the soil can be achieved by biological and physicochemical methods; Electrooxidation method was preferred in this study because it does not create a secondary pollutant, is easy to use, has high removal efficiency and completely mineralizes organic pollutants that are difficult to decompose into carbon dioxide. In this study, the color removal of textile dyestuff from polluted soils in the electrooxidation reactor system was investigated by using BDD anode electrode from Reactive black 5 (RB5) dye solution. In the study, dyestuff removal was investigated by creating three different media: dyestuff (1), sand- dyestuff (2), sand-peat-soil- dyestuff (3). As a result of the study, when high current (0.04A) is applied, dyestuff removal rate is close to each other (87% (1), 90% (2), 84% (3)) in all 3 environments, but when low current (0.005A) is applied, 2 and 3 It was determined that the dyestuff was removed at a better rate (41% (1), 72% (2), 62% (3)) from media no. At low current density, this efficiency difference between the reactor no. (1), where the filler is not used, and the other reactors (2), (3) where the filler is used, was attributed to the fact that some reactive agents such as Cl, which may come from the filler (sand, soil) in the filled reactors, cause indirect electrooxidation and increase the efficiency.