FIELD: water treatment by biological methods. SUBSTANCE: method involves anaerobic treatment at the first stage and aerobic one at the second stage. Water is passed through the coal layer containing immobilized microorganisms. Quantity of impurities, which is fed into every reactor, is maintained at the level 4,5 g and 0,6 g chemical oxygen consumption 1 kg load/24 h, respectively. EFFECT: improved method of water treatment. 1 tbl
