Abstract:

The object of research is wastewaters contaminated with dyes. The available methods for treating wastewater from dyes are often imperfect, ineffective or absent. This calls for the development and implementation of efficient and inexpensive to use and operate dye removal technologies. When treating wastewater, the biggest problem is removing the dyes from dilute low-concentration solutions. For the purification of such effluents, solvent sublation is suggested. This method is based on a combination of flotation and extraction techniques, and on the transmission of gas bubbles through the aqueous phase and removal of the pollutant (sublate) into the organic phase. During the study, imitates of contaminated wastewater with an anionic dye bromocresol green are used in the concentration range of 2–20 mg/dm3. The influence of some parameters on the dye removal degree is studied: the pH of the initial solution, the molar ratio surfactant: dye, the size of the air bubbles, the initial concentration of the dye, and the solvent sublation duration. The rational conditions for removing the dye are established: pH 3–3.5, molar ratio bromocresol green-hexadecylpyridinium chloride=1:1. Effective removal of the dye is ensured by using a Schott filter with a pore diameter of 100 μm, an air flow rate of 110–120 cm3/min, duration –10 min. Under these conditions, the dye removal degree is 88–99 %. The obtained results confirm the prospects of the proposed method for the effective removal of dyes from low-concentration aqueous solutions. The method has several advantages: possibility to work with large volumes of water bodies; active substance is carried out by gas bubbles and enters the hydrophobic liquid layer without mixing the phases; process is not equilibrium and is not limited by the distribution constant; impossibility of formation of emulsions; multiple concentration of ions in small volumes of organic solvent; requires a small amount of extractant compared to liquid extraction. Author Biographies Tetjana Obushenko, National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute», 37, Peremohy ave., Kyiv, Ukraine, 03056 Senior Lecturer Department of Inorganic Substances, Water Purification and General Chemical Technology

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