Epuration des eaux usées par lagunage naturel de la région de Ghardaia Evolutions et conditions optimales

Abstract

The purpose of this study is the follow-up assessment of physico-chemical parameters of treated wastewater in the STEP before and after treatment for five months (January, February, March, April and May) to study the purification performance of water pollutants. The results show that the treatment performance are good and are above 60% for most parameters. In fact, the average rate of drawdown calculated are of the order of 67.10% (MES), 66.2% (DBO5 ), 65.24% (DCO), and with fairly acceptable means drawdown rate for the other parameters 12.9% (N-NH4 + ) , 28.57% (N-NO2 - ), 45.19% (N-NO3 - ) and 13.94% (N2 total) during the five-month follow-up. These performances are generally close to the ranges of performance required by Algerian law and may be improved after a good development and good coverage of lagoons. The experience of wastewater treatment by stabilization ponds to STEP Kef Dokhan (Ghardaia) shows the current and acceptable treatment efficiency and facilities, operation and maintenance are less expensive and more beneficial to the environment.