Bioaccumulation of heavy metals by green algae Cladophora glomerata in a refinery sewage lagoon

Green algae, especially Cladophora species, are generally considered as the best bioindicator of aquatic bodies contamination by nutrients as well as by heavy metals. Therefore, the object of this study was to investigate to which extent toxic metals (Ni, V, Cd, Pb, Cr) are present in algal biomass and to establish the bioaccumulation coefficients in correlated algae/water environments in a sewage lagoon, which represents the tertiary stage of a refinery waste water treatment plant (Slovnaft, Bratislava). Due to the oro graphic depression between the Eastern Alps and Western Carpathians and the characteristic atmospheric circulation with predominance of NW wind direct ion, the deposition of heavy metal aerosols from closed industrial activiti es is expected to contribute to bioaccumulation capacities of algae for the se elements. The water of the refinery sewage lagoon has been monitored for BOD, GOD, petroleum hydrocarbons, pH, BTX, halogenated hydrocarbons, some polyaromates, phosphates, ammonium, sulfates and suspended matter. From the viewpoint of heavy metal contents in agricultural composts, a management s cenario for algal biomass reutilization, i.e. recycling nutrients and prote ins back into the biosphere, via compost processing, is proposed.