Traitement des eaux usées par culture de micro-algues: Influence de la composition du milieu sur la croissance de Scenedesmus sp

Abstract

After a short review of the present knowledge concerning the treatment of polluting effluents with microalgal cultures, the results of a laboratory work done with a domestic effluent are presented. The epuration capacity and growth of cultures of Scenedesmus made with modified media have been compared in order to identify the controlable factors that may effect performance. For nitrogen and phosphorus a removal of more than 90 % has been obtained within 48 h. Starting with a small inoculum (2 mg/L) the biomass increased up to the 7th when it reached about 350 mg dry weight/L, without any noticeable difference between the three culture media used (raw effluent, filtered effluent and filtered CO2 - enriched effluent). The addition of vitamins to the raw effluent or to an artificial effluent was without significant effect on Scenedesmus sp. growth. Among the nine media studied, the raw effluent produced a growth superior to that of synthetic medium and similar to that of filtered effluent, even when enriched with CO2. The results obtained demonstrate the potential fo Scenedesmus sp. as a tertiary treatment agent. © Masson, 1989.