Use of various high molecular weight synthetic compounds as flocculants allows considerably increase the efficiency of physical-chemical methods for industrial wastewater treatment. Doing this, potential severe effects of residual amounts of these compounds on water organisms are not taken into consideration. Ecological-toxicological assessment of six flocculants: Magnafloc E1O, Zetag 64 (Germany); Sanfloc N520P, Sanfloc CH009P (Japan); Catfloc (U.S.A.); Polyacrylamide-PAA (Russia) was done in the course of our study. Flocculant toxic effects on water organisms of various systematic groups were found using international biotesting parameters. The flocculants affected all water ecosystem components and, especially, protococcal algae, invertebrates and adult fish. Acute and long-term experimental results showed the necessity of establishing maximum vital concentrations of flocculants. Comparative biological activity studies for different types of flocculants (cationic, anionic and nonionic) showed that cationic ones had the most expressed acute and long-term toxicity. According to the whole complex of pathological effects flocculants seem to possess the membranotropic mode of action. The results indicate flocculants as a new micropollutant class with high toxicity for water organisms. The control of their residual amounts in effluents discharged into receiving waterbodies is needed.
