Eaux Usées brutes - Sciencelib

concentration maximale de 227,2 mg/L tandis que les concentrations des
formes oxydées de l’azote sont généralement faibles. Les teneurs en
orthophosphates oscillent entre 2,4 mg/L et 36,9 mg/L. La charge polluante
est comprise entre 72,5 mg/L et 281 mg/l pour la DBO5, 312 mg/L et 795
mg/L pour la DCO et entre 102,2 mg/L et 218 mg/L pour les matières en
suspension.
Mots clés : eau usée brute, Nouakchott, Mauritanie.
Study of the physicochemical quality of raw sewage from the city of
Nouakchott
ABSTRACT
The main goal is to monitor the physical and chemical quality of raw sewage
from the city of Nouakchott. The monthly collections were made at the
collector of the WWTP between February 2008 and July 2009. The
parameters studied are temperature, pH, electrical conductivity, chlorides,
bicarbonates, nitrates, nitrites, ammonium, orthophosphate, COD, BOD5,
oxidizing matters and suspended matters.
The test results presented in this work have shown that raw sewage from the
city of Nouakchott maximum temperatures up to 32.2 ° C. The pH varies
between 6.5 and 10.7. The salinity was determined from the measurement of
electrical conductivity which is around 1200 µS /cm at 4900 µS / cm. The raw
sewage from the city of Nouakchott is characterized by high mineralization
with maximum levels of chlorides and bicarbonates are respectively 1284 mg
/L and 1852.7 mg /L. With regard to nitrogen compounds is found that
nitrogen is found mainly in the ammonium form with a maximum
concentration of 227.2 mg/L while the concentrations of oxidized forms of
nitrogen are generally low. The levels of orthophosphate ranged from 2.4 mg
/L and 36.9 mg /L. The pollution load is between 72.5 mg /L and 281 mg / L
for BOD5, 312 mg /L and 795 mg /L for COD and between 102.2 mg /L and
218 mg /L for suspended matters.
Keywords: raw sewage, Nouakchott, Mauritania.
ScienceLib Editions Mersenne : Volume 3 , N ° 110703
ISSN 2111-4706
3
Abdoulaye Demba N’DIAYE