Abstract

This study purpose to assess the real share of nitrogen the household and similar solid wastes can release in direct contact with water. The maximum amount of nitrogen could release was determined by a leaching test. The concentrations of total and organic nitrogen, ammonium and nitrates ions and the pH values were measured in the initial and incubated juices. The leaching test showed that the solid waste can release 261 mg of total nitrogen (TN) in water for 1 kg of dry waste. This amount of total nitrogen corresponds to 240.1 mg of organic nitrogen (OrgN), 17 mg of ammonium nitrogen (〖NH〗_4^+-N), 3.3 mg of nitrate nitrogen (〖NO〗_3^--N) and 0.4 mg of nitrite nitrogen (〖NO〗_2^--N). The monitoring of the nitrogen biotransformation has shown a good disposition of the organic nitrogen to be transformed into ammonium ions and the ammonium ions into nitrate ions. By 2025, the forecast calculations of nitrogen input into the river's waters show that the zone downstream of the river and the heart of the city will be more impacted by nitrogen pollution. The expected variations in total nitrogen (TN) and nitrate ion 〖(NO〗_3^--N) concentrations are respectively between 6.49 and 8.85 μg/L and 0.35 and 0.87 μg/L. These concentrations are considered weak but by interacting with the release of sediments during the dry season they can participate at the eutrophication process. Leaching and incubation test can be used to forecast the negative impact of solid waste on the river.

Keywords: Solid waste, nitrogen, biotransformation, river water quality, eutrophication.