Removal of biogenic elements, polychlorinated diphenyls and heavy metals during the biological final treatment of waste-waters.

Algae were cultivated in the effluents from a treatment plant processing communal sewage and waste-water from a large-scale hoggery. The content of nitrogen. phosphorus and also COD and BOD were estimated in the effluent before and after cultivation of algae. It was found that the removal of nitrogen and phosphorus by Chlamydomonas geitleri from the effluent was optimal at highest at the high effluent concentrations while the purification efficiency in relation to PCD content depends on algae used.