Open AccessPOLLUTION OF WELL WATER WITH SOME NITROGENOUS POLLUTANTS AND TOXIC MICROPOLLUTANTS IN THE SIXTH DISTRICT OF COTONOU IN SOUTH-BENIN
Author(s) -
Espérance Olive Hounsounou,
Lucie Ayi-Fanou,
Victorin Chégnimonhan,
Euloge Kossi Agbossou,
Agassou Djikpo Tchibozo Micheline,
Guidi Tog Clotilde
Publication year - 2018
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta
Language(s) - English
Resource type - Journals
eISSN - 2687-1076
pISSN - 1812-9498
DOI - 10.24143/1812-9498-2018-1-110-120
Subject(s) - pollutant , pollution , environmental chemistry , mercury (programming language) , environmental science , nitrate , cadmium , water pollution , chemistry , mineralization (soil science) , nitrogen , ecology , biology , organic chemistry , computer science , programming language
Difficulties of access to public water distribution sources in the suburbs of the sixth district of Cotonou create more resorts to the traditional water sources (wells). To assess the degree of chemical pollution of those waters, a study was conducted during the long rainy season of 2015 on thirty (30) traditional wells. Concentration of nitrogenous pollutants (nitrates and nitrites) was analyzed by cadmium reduction method and diazotization method, respectively. Micropollutants (lead and mercury) were respectively determined by the rapid extraction method of LeadTrak ™ column and by pre-concentration at cold vapor method. The results show that waters have a high level of nitrate and mercury pollution which are respectively 26.67%, (16.38 mg/l to 349.85 mg/l) and 13.33% (0.10 mg/l to 1.50 mg/l) and a low level of nitrite (0.02 mg/l to 2.63 mg/l) and lead (1 mg/l to 5mg/l). The Principal Component analysis helped to identify four groups (I-IV) of well waters: water with high degree of nitrogen pollution (NO3-) and high toxic metal and toxic metal (I: 20%); with low degree of nitrogen and toxic metal (II: 30%);water with high mineralization (III: 20%) and water rich in nitric pollutant (NO2-) (IV: 6.67%).The water pollution may be related to the low sanitation level and the improper conditions of well installation. Consumption of well waters may expose humans to health risks.