Research of the wastewater treatment method for the production of wood-chip building materials in the presence of nanostructured heterogeneous catalys

Introduction. Phenols and petroleum products are common wastewater contaminants in many industries. Due to their persistence and toxicity in the natural environment, an efficient waste disposal technology is needed. Ozonation in the presence of heterogeneous catalysts is one of the advanced methods for treating wastewater from these toxicants. Since most catalysts are expensive, they are being sought on the basis of transition metals and their oxides, which have high activity and relatively low cost. In this regard, the Scientific and Educational Center for Innovative Technologies (SECIT) of USPTU carried out work on the search for an effective and affordable catalyst for the deep oxidation of phenol and petroleum products in wastewater under the influence of ozone. Methods and materials. To study catalytic ozonation, we used model waste water containing phenol and oil products at concentrations of 8 and 30 mg/dm3, respectively. Ozonation was carried out in the presence of fresh (1) and spent (2) NiO-MoO3 catalyst deposited in the form of a film on cylindrical Al2O3 granules weighing 0.5 - 2 g. Results. Optimal conditions of ozonation have been found (1), within 10 min of the decomposition process in its presence, COD decreased by 25% compared to the oxidation process with a catalyst (2), and by 40% compared to classical ozonolysis. It was found that the optimal loading of catalyst (1) is 1 g, duration is 35 min, pH = 8.5, temperature - 22 - 30°C, ozone dose - 5 g/dm3. Discussion. At catalyst dosages of less than 1 g/dm3, the low efficiency of removing phenol and hydrocarbons is probably due to a lack of the adsorption surface of the catalyst. Conclusion. The studied method of purification allows to reduce the content of phenol and oil products to the standard indicator of drinking water quality (0.001 and 0.05 mg/dm3, respectively), COD by 96% and solve the problem of the harmful effects of these toxicants on ecosystems.