EVALUATION OF NITRATE CONTENT OF 35 WELL WATER OF KOLDA DISCTRICT

Abstract

Nitrates are not harmful at physiological doses, but bacteria in natural environments and in the oral cavity reduce nitrate to nitrite which harm the human digestive system and are sometimes the cause of stomach cancer and methemoglobinemia in infants. Faced with these alarming findings, the maximum levels of nitrates in drinking water has been set at 50 mg / l (or 8.10-4 mol / l) by the World Health Organization. Given the well water nitrate content, so it has seemed necessary to determine nitrate levels in some samples of well water from the town of Kolda. The assay done with nitrates specific electrode allowed us to know the amount of nitrate in thirty five well water samples from the town of Kolda. The results obtained after averaging showed high levels of nitrates. More than half of the assayed samples had higher nitrate contents in the standard set of 49% having levels below 900 mg / l and 17% exceeding 900 milligrams nitrate per liter. However well water is not the only source of nitrate, we’ll also take into account other sources in the monitoring of toxicities occurrence. Keywords: nitrates - well water - Kolda - electrode