The purpose of the presented research is to analyse possible methods of thickening of the Microcystis aeruginosa (Kützing) Kützing cyanobacteria using the obtained concentrate as a biomass for the production of energy carriers and bio-logically valuable substances. Method of cyanobacteria thickening under the action of electric current and in the electric field, as well as the method of coagulation–flocculation and gravity thickening, was experimentally investigated in lab-scale conditions. Electrical methods didn't show positive results for the Microcystis aeruginosa thickening, despite the re-ports of their potential efficiency in a number of previous studies. The high efficiency of the method of coagulation–flocculation and gravity thickening of Microcystis aeruginosa suspensions was obtained. The optimum concentrations of industrial polymeric coagulants and flocculants for the thickening of Microcystis aeruginosa suspensions were defined in the range of about 10 ppm for the coagulants and about 1 ppm for the flocculants. Negative effect of the previous cavitational treatment of the diluted suspensions of Microcystis aeruginosa on the effectiveness of the coagulation–flocculation and gravitational thickening was confirmed experimentally. Hydrodynamic cavitation should be recommended to use after the thickening as the next step of processing of concentrated suspensions of Microcystis aeruginosa to achieve maximum extraction of energy carriers and biologically valuable substances.

Hydrobionts are considered as highly potential source for bioproduction (including energy carriers and fertilizers) and many biotechnological processes that include hydrobionts, particularly their biomass as a substrate are used in different fields of energy, cosmetology, medicine, pharmaceutics, aquaculture, agriculture, forestry etc. Latest developments prove efficiency in applying anaerobic digestion for purifying wastewaters from organic pollutants with the help of macrophytes and microphytes in conducting biomethanogenesis. Many studies have established that it is possible to reach high level of lipid extraction from algae (to 95%) with the help of organic solvents (methanol, acetone, hexane, diethyl ether etc). Blue – green algae biomass has been scientifically proved to be a good source for methane, methanol, ethanol, propanol, isopropanol, biodiesel and other biofuel types production. Macroalgae and microalgae contain β- carotene, biotin, folic acid, fucoidans, lectins, phenolics, sulphated polysaccharides and other derived biologically active compounds that can be used in producing vitamins, have anti-ulcer, antioxidant, antibiotic, antifouling, immune modulatory and other properties. Cyanidioschyzon merolae, Ostreococcus lucimarinus, O. tauri, Micromonas pusilla have shown high potential for hydrogen production while Rhizoclonium sp. has been experimentally used as a bounding material in briquetting miscanthus granules, resulting in 20 % higher dynamic strength. The article is a literature review and the purpose of this work is to classify and systemize hydrobionts, reveal regularity of their growth, conduct critical analysis on existing biotechnologies on using separate representatives of aquatic biomes as a raw material and also to review ways of intensification for these biotechnologies.