IMPACT OF POLLUTION ON THE PHYSICAL, CHEMICAL, AND BACTERIOLOGICAL PARAMETERS OF DRINKING WATER FROM SEVERAL WELLS IN THE MUNICIPALITY OF KANKAN (GUINEA)

The issue of access to drinking water is a major challenge, particularly in developing countries such as Guinea. That is why this study set out to examine the factors affecting the quality of drinking water from 20 unimproved wells in the Kankan region (Republic of Guinea). The study began with a survey of the environment surrounding the wells under investigation. Next, pH, temperature, and turbidity were determined according to standard NF T 90-008, while conductivity was determined according to standard NF EN 27888. Chlorides were measured by titrimetry, while major ions (NO3 -, NO2-, NH4+, PO43-, SO42-) were quantified by molecular absorption spectrophotometry. The results obtained show that most wells are in a critical state of unsanitary conditions. Physicochemical analyses reveal that pH and turbidity, which vary from 4.986 to 7.624 and from 0.84 to 29.6 NTU, respectively, do not meet WHO standards in many cases. The levels of ammonium ions (NH4+), nitrate (NO3 -), nitrite (NO2-) and sulfate ions (SO42-) comply with WHO standards. However, phosphate ion (PO43-) levels ranging from 0.24 to 9.81 mg/L do not meet the standards for many wells, while only one of the twenty wells has a chloride (Cl-) level of 255.31, which is above the WHO standard. Bacteriological parameters indicate that several wells are contaminated, mainly by total coliforms. The poor water quality of some wells could be correlated with their unsanitary condition.