Generalities
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 Agriculture: the algal biomass produced is rich in essential nutrients for plant growth
can be used as fertilizer and soil stabilizer in agriculture.
 CO2 sequestration: microalgae are extremely efficient in this process, as during
photosynthesis they can absorb up to 5 times more CO2 than terrestrial plants (Tebbani
et al., 2014).
1.2. Generalities on Wastewater treatment processes
The aim of wastewater treatment is to obtain purified water that meets the discharge
standards laid down by legislation and that can be used as part of the measures required for
good water management (recycling), Depending on the nature and extent of the pollution,
different processes can be used to purify urban and industrial wastewater, depending on its
characteristics and the degree of purification required.
1.2.1. Waste water
1.2.1.1. Definition of wastewater
Wastewater is water which has undergone a deterioration and transformation of its
natural properties after use, and which has become laden with soluble or insoluble pollutants
(Bliefert & Perraud, 2001). It represents a danger for users and receiving environments, which
involves going through a treatment chain to remove all toxic elements.
1.2.1.2 Wastewater composition
The composition of wastewater can vary according to its origin (Domestic, agricultural,
industrial or rainwater). It may contain several substances, in dissolved or solid form (figure
10), as well as numerous microorganisms.