REMOVAL OF PHENOL FROM WATER BY BACILLUS SUBTILIS ONU551 BACTERIA, ADHESIZED ON THE CARRIERS OF DIFFERENT NATURE

Abstract

Aim. Investigation of the efficiency of removal phenol from water by bacteria Bacillus subtilis ONU551 adhered on the carriers of different nature. Methods. The concentration of phenol in water was determined by extraction-photometric method using 4-aminoantipyrin. The significance of the differences between the mean values of the residual concentration of phenol in water was determined by Student's criterion at a significance level of at least 95% (p ≤ 0.05). Data processing was performed using the program Microsoft Office Excel 2003. Results. The ability of a B. subtilis ONU551 bacterial strain isolated from waste water produced by pharmaceuticals to oxidize phenol was experimentally established. The concentration of phenol in water during its treatment with free cells of the B. subtilis ONU551 bacterial strain in the amount of 5.5×105 CFU/ml for 5 days of exposure decreased from 200.0 to 112.0±5.5 mg/l (by 44% ), reaching maximum on the 15th day – the degree of phenol removal from water was 99-100%. Adhesion of B. subtilis ONU551 bacteria to the surface of natural (zeolite, peat, activated carbon, sand), synthetic (ceramic tubes, fibrous nozzles of the “VIYA” type) of carriers accelerated the removal of phenol from water 1.4–2.5 times , compared to the treatment of water by free bacterial cells. The residual concentration of phenol in water during its treatment with B. subtilis ONU551 bacteria adhered on sand and on “VIYA” type fiber packing decreased for 6 days from 200.0 mg/l to 9.0±0.25 mg/l and 6.0±0.54 mg/l, respectively (by 95–96%) and on the 11th day was at the level of maximum permissible concentration (0.001 mg/l). The degree of removal of phenol from water by B. subtilis ONU551 bacteria adhered on mussel doors, peat and zeolite at the end of cleaning (11 days) ranged from 87% to 99%; and reached 100% – when used as the carriers of activated carbon, ceramic tubes. Conclusion. The use of B. subtilis ONU551 bacteria adhered on natural and synthetic carriers – mussel shutters, peat, sand and fibrous attachment of “VIYA” type ensures 100% removal of phenol from water.