Application of a Magnetic Field in Liquid Extraction Treatment of Wastewater

Abstract

One of the primary challenges faced by industrial enterprises involves the reuse of treated water. In paint and coating production, water becomes contaminated with various organic solvents, including butyl glycol, acetic acid, acetylacetone, and others. Efficient treatment and reintegration of this water into the technological process represent critical objectives. This study reports the results of single-stage liquid-phase wastewater treatment under the influence of a magnetic field with a magnetic induction of 20 mT, achieving purification efficiencies of 99.3% for butyl glycol, 99.1% for acetic acid, and 99.8% for acetylacetone. Isopropyl alcohol served as the extractant. The volumetric flow rates of wastewater and extractant were 3.0 and 0.3 dm³/h, respectively. The diameter of the extractor and the openings through which the extractant passes were d_extr = 0.03 m and d_op = 0.5 mm, respectively. Using a differential cell model, the concentrations of components in equilibrium phases along the height of the apparatus were calculated, along with the number of theoretical stages and the extractor height. The concentrations of components in the raffinate at the 20th cell were nearly identical to their initial concentrations, leading to the assumption of 20 theoretical stages. Given that the distance between theoretical stages is Δh = 0.05 m, the height of the extractor, with a diameter of 0.03 m, was calculated to be H_extr = 20 × 0.05 = 1.0 m. The degree of component extraction along the height of the extractor was also calculated. A zero-waste technology was proposed for treating wastewater contaminated with organic solvents to achieve maximum permissible concentrations (MPCs) using single-stage liquid–liquid extraction under the action of a magnetic field.