Experimental research on water chemistry evolution in case of inadequate conservation protocols: application on surface and groundwater

The objective of this study conducted from October to December 2020 in the Natural Resources and Sensitive Environment Development Laboratory was to demonstrate the importance of conservation protocols respect throw evolution of water chemistry. Ninety-nine samples representing three water types (tap, spring and mineral water) were analyzed. Storage was at laboratory temperature with no conservation protocol. Studied parameters (temperature, pH, CE, dissolved oxygen, oxydo-reduction potential, total dissolved solids, HCO3−, Ca2+, Mg2+, SO42− and Cl−) were determined using standard methods. The data registered from physico-chemical parameters were subjected to different analytical methods to assess the time affect on their values compared with initial state. The results indicate that pH and alkalinity (exprimed in HCO3−) are the most vulnerable to evolution processes with highly significant time factor effect, while the concentrations of chlorides and sulfates with conductivity levels are statistically less evolved. PCA analysis accounting 71.43% of the total variance examines contribution of water type composition as a second variation factor. Projection through F1*F2 plan demonstrates clearly two groups with surface waters (tap water) which are excessively mineralized and groundwaters (spring and bottled waters) in which pH and magnesium parameters variations are the best illustrated.