Photocatalytic wastewater treatment from formaldehyde

Abstract

The article presents the results of studies of treatment of wastewater at woodworking companies which is formed during manufacture and application of adhesives based on urea-formaldehyde resins. There presented a method of wastewater purification from pollutants such as dissolved components of urea-formaldehyde resins and free formaldehyde. This paper describes a method of pre-stabilization of wastewater for further treatment, which is achieved by precipitation of the condensation products of urea and formaldehyde. Stabilised wastewater is further subjected to processing by UV-radiation. In-vestigations were carried out with the wastewater, which were selected at the wood-processing enterprises of Belarus and wastewater has the following composition: formaldehyde content − 1.0−5.0 g/dm{3}, chemical oxygen demand (COD) of the liquid phase – 15.0 −60.0 g O[2]/dm{3} of components UFR − 50.0 −80.0 g/dm{3}. Various treatment options of stabilized wastewater by UV-radiation are investigated. It was established that UV-treatment of wastewater containing formaldehyde in the presence of powder composite material comprising TiO2, at a dose of irradiation of 10.8 J/cm{2} and and pH value being equal to 11 to reduced the formaldehyde content to 97% formal dehyde at concentrations ranging from 10 to 150 mg/dm{3}. Schematic diagram of wastewater treatment containing components UFR are proposed.