Organic and inorganic substances which were released into the environment as a result of
domestic, agricultural and industrial water activities lead to organic and inorganic pollution. The
normal primary and secondary treatment processes of these wastewaters have been introduced in
a growing number of places, in order to eliminate the easily settled materials and to oxidize the
organic material present in wastewater. The final result is a clear, apparently clean effluent which
is discharged into natural water bodies. This secondary effluent is, however, loaded with inorganic
nitrogen and phosphorus and causes eutrophication and more long-term problems because of
refractory organics and heavy metals that are discharged. Microalgae culture offers an interesting
step for wastewater treatments, because they provide a tertiary biotreatment coupled with the
production of potentially valuable biomass, which can be used for several purposes. Microalgae cultures
offer an elegant solution to tertiary and quandary treatments due to the ability of microalgae
to use inorganic nitrogen and phosphorus for their growth. And also, for their capacity to remove
heavy metals, as well as some toxic organic compounds, therefore, it does not lead to secondary
pollution. In the current review we will highlight on the role of micro-algae in the treatment of
wastewater.