The biological study of a wastewater treatment plant by natural lagoon systems is an important aspect, especially as the Hammam-Foukani station is the first experience of wastewatertreatment in Figuig.

We focused on qualitative and quantitative monitoring of phytoplankton over a two year period. Microscopic observation showed significant proliferation of Cyanobacteria such as Scynechocystisand Pseudoanabaena, as well as Chlorophyceae and Euglenophyceae. Chlorellashowedstronggrowth in hot periods, while diatoms are moderately abundant downstream of the station.

The quantitative aspect indicates a strong phytoplankton bloom in summertime, measured as well by dosing chlorophyll pigments and by counting algal cells.

Rising temperatures and pH values ​​as well as strong sunlight are the main factors for control of algal and cyanobacterial biomass.