Sudy of Factors Influencing Leachate Characteristics Before Treatment

Abstract

The problems of disposal, treatment, and general management of municipal waste in developing countries remain crucial. With demographic evolution, forced urbanization, and the improvement of the standard of living of each country, the quantity of urban waste produced does not stop growing. Whatever its mode of operation, a technical landfill can be a source of several sources of nuisance: odor emissions, production of biogas, and above all production of large quantities of leachate. New leachate treatment techniques have appeared such as membrane processes, biological processes, and Physico-chemical processes. However, the effectiveness of these processes on an industrial scale is limited, mainly because of the high polluting load of the leachate concerned and the instability of the leachate in terms of quality which is due to several factors such as seasonality, and the leachate age. The Hassi Bounif leachate treatment plant, located in the wilaya of Oran, Algeria, has been failing since 2017 only after a few months of its commissioning. With the overall objective of restarting and optimizing the performance of the Hassi Bounif leachate treatment plant, it was necessary to study the factors influencing the quality of leachate and their mode of influence. The objective of this work is to determine the physicochemical characteristics of raw leachate according to its age and according to meteorological parameters.For this, several leachate samples were taken from 04 recovery basins with a deferred age: young, intermediate, and stable for two seasons. The main characteristics analyzed are density, pH, conductivity, temperature, BOD, COD, total nitrogen and heavy metals, and micropollutants. The results showed that: 1. The young leachate is acid unlike the intermediate leachate and stable leachate which are basic. It is denser, its conductivity is higher, and the temperature at the surface of the young leachate basin is higher, on the other hand, its biological oxygen demand is the lowest, which is explained by the aerobic chemical reactions at the surface. and that the microorganisms have not yet come into play. 2. The season has an impact on the leachate quality; in the dry season, the leachate is less dense than in the wet season, the pH and conductivity values are high in the dry season compared to the wet season, and the surface temperature of the liquids depends on the ambient temperature and the leachate age, The results of this work show the importance of controlling the characteristics of leachate according to its age and seasonality as well as other factors such as homogenization before opting for any leachate treatment technique, This will allow better operation of the treatment facilities.