Étude des performances épuratoires de la station d'épuration des eaux usées domestiques par filtres plantés de Ksar de M'raguen (Adrar)

Abstract

In this six-week study (from January 30 to March 7, 2017), the interest was in evaluating the performance of the purification treatment system of domestic water. The treatment of wastewater from 824 inhabitants of the Ksar (village) of M'raguen is done by the succession of two stages: pretreatment (screening and degreasing), and biological treatment that consists of two filters working alternately using reeds. Each filter contains a layer of sand, gravel and rubble. The evacuated water from the basin is used in watering the trees of the station and the rest is thrown outside the station 2 km away. The measurements were based on pH, temperature, electrical conductivity, turbidity, Suspended Matter (SM), Organic Matter (OM), Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), ammoniums, nitrites, nitrates, orthophosphates and total and fecal coliforms. These parameters are checked at the input and output of the station.

The study yielded good results for particulate and organic pollution, abatement rates of 91% for Suspended Matter (SM), 62 % for organic matter (MO), 73 % in terms of Chemical Oxygen Demand (COD), 93% in terms of Biochemical Oxygen Demand (BOD), 70 % for orthophosphates, was achieved. However, there is a clear progression for ammoniums, nitrites and nitrates.

The results also show very good performance for the elimination of pathogenic pollution, with a rate of reduction of 95% of total coliforms and 97% of fecal coliforms.