PURIFICATION OF WATER FROM PHENOL AND IONS OF HEAVY METALS BY THE ASSOCIATION OF BACTERIA OF THE GENUS PSEUDOMONAS

Abstract

Aim. Purification of water from phenol and heavy metal ions using bacteria of the genus Pseudomonas. Methods. The effectiveness of microbial purification is estimated by the degree of extraction from the water of cyclic aromatic compounds - phenol and heavy metals [Pb (II), Cd (II), Zn (II)]. The phenol concentration was determined by the extraction-photometric method using 4-aminoantipyrine; heavy metals – by atomic absorption method on flame atomic absorption spectrophotometer Saturn in the flame of the air-propane-butane mixture. Results. The strains of P. fluorescens ONU328, P. maltophilia ONU329, P. cepacia ONU327 were used for the first time to purify water from cyclic aromatic compounds (phenol) and heavy metal ions. It was found that in the presence of individual strains of microorganisms in the amount of 7.5×105 CFU/ ml for 18–22 days (depending on the chosen strain) complete dephenolization of aqueous solutions occurs. When using the association of strains P. fluorescens ONU328, P. maltophilia ONU329, P. cepacia ONU327 (1: 1: 1 in volume ratio), the deep water purification from phenol with the initial concentration in water of 300 mg/dm3 is reduced to 10 days. The degree of extraction of Pb (II), Cd (II), Zn (II) from concentrated solutions by individual strains of microorganisms in the composition of biofloques reaches 95,00–99,95% with residual content of heavy metal ions in solution (0,03–1,0) mg/dm3. Using the association of strains of P. fluorescens ONU328, P. maltophilia ONU329, P. cepacia ONU327 provides the greatest efficiency of water purification from cations of heavy metals. In the treatment of metal-containing solutions immobilized in a biofloaclular bacterial cell, the residual concentration of Pb (II), Cd (II), Zn (II) is 0,03 ± 0,001, 0,02 ± 0,001 and 0,03 ± 0,004 mg/dm3 accordingly, that does not exceed the maximum permissible concentration in purified waters for discharge into the sewage system. Conclusion. The used strains of bacteria of the genus Pseudomonas are characterized by polyfunctional potential of biotechnological purpose – destructive to phenol and sorption-accumulating relative to ions of heavy metals, which reveals the prospects of their use in complex biotechnology of environmental purification from the pollutants of different nature.