Methodology
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 Nutrient loads
 Phosphorus loads
The phosphorus content in domestic wastewater per inhabitant per day
is estimated at 15 g/inhab/d. It is calculated using the following formula:
P load= N × 15 × í µí¿í µí¿Ž
−𝟑
Where :
P load : phosphorus polluttant load.
N : Number of equivalent inhabitants by 2050.
• In concentration (mg/l)
[P]=
𝑷𝒐𝒍𝒍𝒖𝒕𝒂𝒏𝒕 𝒍𝒐𝒂𝒅 𝒊𝒏 𝒑
𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝒅𝒂𝒊𝒍𝒚 𝒇𝒍𝒐𝒘 𝒓𝒂𝒕𝒆
• Purification yield
The pufirication yield is given by the following formula:
R=
𝑪 𝒊− 𝑪 𝒇
𝑪 𝒊
×100
With :
Ci: Phosphorus concentration at plant inlet.
Cf : Phosphorus concentration at plant outlet ([P] =10mg/l).
 Nitrogen loads
Nitrogen content in domestic wastewater per inhabitant per day is estimated at
20 g/inhabit/d. It is calculated using the following formula
A load =N×20×10
-3
with :
A load: Nitrogen pollutant load.
N: Number of equivalent inhabitants by 2050.
• In concentration (mg/l)
[A]=
𝑃𝑜𝑙𝑙𝑢𝑡𝑎𝑛𝑡 𝑙𝑜𝑎𝑑 𝑖𝑛 𝐴
𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑑𝑎𝑖𝑙𝑦 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒