Methodology
61
 Volume load (Cv)
0.1 3 /d.
The volume load refers to a certain weight of organic matter expressed as BOD5 (Kg/d)
that must be transferred to a pond of volume V (m
3 ). The volume load is defined as the
ratio of pollution per unit of pond volume.
The plant calculation will be based on the following value:
Cv = 0.8 Kg BOD5/ m
3 / d In order to size the ponds, we need to make the following
 Calculation of the pollutant load at pond outlet (LF)
The pollutant load calculation method used in this study is the BOD5
concentration calculation method.
The BOD5 concentration at the plant outlet must comply with the WHO
discharge standards applied in Algeria, which are of the order of 30 mg/l.
This gives:
LF= SS × í µí±¸ 𝒂𝒗𝒆𝒓.𝒅
With :
LF: pollutant load at plant outlet (Kg BOD5/d).
SS: BOD5 concentration at plant outlet (Kg/m
3 ).
𝑸 𝒂𝒗𝒆𝒓.𝒅 : verage daily wastewater flow(m
3 /d).
 Calculation of the eliminated pollutant load (EL)
The following formula is used:
EL= L0- LF
With:
LF: Pollutant load at pond outlet (kg BOD5/d).
𝐿0: BOD5 pollutant load at pond inlet (kg/d).
EL: BOD5 pollutant load removed (kg/d).
 Calculation of the purification yield (𝜼𝒆𝒑)
We have:
𝜼𝒆𝒑=
𝑳 𝟎 −𝑳 í µí±í µí±³ 𝟎
×100=
𝑬 𝑳
𝑳 𝟎
×100
With :
𝜼𝒆𝒑 : The removal efficiency (%).