As the urbanisation level increases, due to intensification of car traffic and increased areas of impermeable surfaces, pollution of surface wastewater and a negative impact on water bodies are increasing. Due to the increasing pollution of surface water bodies, the eutrophication process is taking place intensively. One of the technologies of surface wastewater treatment allowing reduction in the amounts of suspended solids (SS), heavy metals and other pollutants is surface wastewater filters. Filters with different fillers have been designed for the treatment of principal surface wastewater pollutants: suspended solids, heavy metals (zinc, cadmium, copper, lead), BOD5, total carbon and nitrogen. The Kriging method was adapted to test the efficiency of filters filled with construction waste and wood waste-derived biochar using distance matrices. The method developed makes it possible to model the characteristics of filters in relation to different fillers, using experimental results. The mathematical model is suitable for other filtrate characteristics, not only the ratio of fillers, but also the length of the filter life, its durability calculations, which allows optimizing filter cleaning efficiency up to 96.93 %.
Single cell oil is considered as a promising alternative to fish and vegetable oils. Due to the ability of oleaginous microorganisms to produce significant amounts of polyunsaturated fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), single cell oil can be used for human and animal consumption. In this context, marine microorganisms of the class Labyrinthulomycetes are particularly highlighted in scientific literature. In order to clarify the possibilities for the use of microorganisms of the class Labyrinthulomycetes in large-scale single cell oil production, the first step is to gain awareness of the cultivation conditions required for these microorganisms. In addition, to reduce the cost of single cell oil production, it is necessary to identify potential agroindustrial waste products that are suitable for microbiological cultivation of Labyrinthulomycetes. This article examines the potential biotechnological applications of Labyrinthulomycetes in single cell oil production, the cultivation conditions, nutritional requirements, inhibitors and suitable waste products. In addition, an agroindustrial by-product availability analysis has been carried out. The article evaluates agroindustrial by-products based on their availability in Latvia, required pre-treatment, price, shelf life and efficiency.