Ozonation of woodworking enterprises using a heterogeneous nanocatalyst

Despite the variety of existing methods of wastewater treatment, this problem can not be considered solved for the woodworking industry. Taking into account that the waste water of plywood-board plants includes phenols, formaldehyde and many other toxic substances, the development of a method for their treatment is an extremely important and actual task. In this regard, we studied the effectiveness of wastewater treatment of the Ufa plywood-board factory (UPBF) by ozonation in the presence of the available and most studied heterogeneous catalysts: Fe2O3, applied in the form of nanofilms of 0.5–1.0 mm particles γ-Al2O3; Al2O3, applied in the form of nanofilms 2.5–3.0 mm particles of TiO2; MnO2, applied in the form of nanofilms 2.5–3.0 mm particles of TiO2. Optimal cleaning conditions were determined by the kinetic curves of phenol decomposition. The results of the conducted experiments on catalytic ozonation of wastewater showed a high purification effect. COD decreased 1.7 (Al2O3, MnO2) and 3 times (Fe2O3) compared to non-catalyst ozonation. The obtained results allow us to confidently assert that in order to improve the efficiency of treatment of UPBF’s wastewater needs ozonation to be carried out in the presence of a heterogeneous nanocatalyst Fe2O3, which is used in a small amount, so there is no need to purify water from iron (III) ions as in homogeneous catalysis. The concentration of iron ion (III) did not exceed the maximum permissible concentration in drinking water (0.3 mg/dm3). The effect of treatment of COD is up to 96%. The paper presents physical and chemical parameters of the quality of the original wastewater and after ozonation in the presence of the catalyst Fe2O3. The studied method of purification makes it possible to reduce the content of phenol to the standard quality index (0.01 mg/dm3). Preliminary ozonation of wastewater increases the efficiency of further biological treatment.