Assessment of wastewater biological treatment efficiency and mapping of WWTPs and LTPs in Algeria

Abstract

Objective: In this study, we present the evaluation of wastewater biological treatment by WWTPs (wastewater treatment plants) and LTPs (lagoon-based treatment plants) in Algeria using the results of analyzes of the samples of 108 stations, this work falls within the framework of a survey carried out by the research center in biotechnology (CRBt) in collaboration with ONA (National office of sanitation), and it reflects our interest in preserving the environment, in particular aquatic ecosystems, and determining the different sources of pollution and the most effective methods to cope with and for those that are well managed. Methods: The analyzes concerned various parameters of 108 stations. Temperature and pH were measured directly, in situ, using multi-parameter field probes. For the other parameters (MS, BOD5, COD, NO3, NO2, NH4, TP) the measurements were carried out in the laboratory according to standard and spectrophotometric methods. As well as through the reports of our field visits to the stations and the monitoring of purification processes. Results: The results obtained show us that wastewater biological treatment is effective to a certain extent, whether in a WWTPs or LTPs. We have recorded that the reduction rates of the various pollutants from wastewater, are more efficient at the outlet of WWTPs than those of LTPs, even if we noted, at WWTP level, outgoing values ​​that do not comply with the standards for reuse and preservation of the receiving environment and higher than the Algerian standard for certain parameters. Conclusion: These results indicate that any use of this treated water, especially in agriculture, must take into account their specificity and the extent of its future impact, in particular the case where values ​​are higher than the Algerian and WHO standards.