Comparative Study of Physicochemical Analysis of Borehole Water and Satchet Water

Three types of sachet water samples and three types of borehole water samples all from Owerri Municipal, Imo State were collected and analyzed for physicochemical parameters. A total of twenty (21) parameters including Odour, Colour, pH, Conductivity, Acidity, Alkalinity, Total Solids, Dissolved Solids, Suspended Solids, Dissolved Oxygen (D.O), Chemical Oxygen Demand (C.O.D), Calcium, Copper, Iron, Manganese, Lead, Chloride, Nitrate, Zinc, Magnesium and sulphate were analyzed. The W.H.O recommended standards shows that all the samples are odourless and colourless. Borehole water is 7.1 in pH, while sachet water has a lower value of 6.5. Acidity in sachet water has a mean value of 50mg/l while borehole water has 54mg/l. Total solids of borehole water is higher with a mean value of 15.6mg/l, while sachet water has 5.7mg/l. Alkalinity is higher in borehole water with a mean value of 165, while sachet water has a lower value of 113. Dissolved oxygen in borehole water has a higher value of 1.19mg/l than sachet water with a value of 0.83mg/l. C.O.D is trace in all the samples. Suspended solids in borehole water is 1.02mg/l which is higher than sachet water which has 0.62mg/l. Calcium is higher in borehole water with a value of 3.1mg/l, while sachet water has 1.92mg/l. Copper content is higher in borehole with a value of 1.42mg/l in borehole water, while sachet water has 0.49mg/l. Chloride is higher in sachet water with a value of 64.1mg/l and lower in borehole water 56.2mg/l. Manganese and Lead values of borehole water are 0.54mg/l and 0.77mg/l respectively, which are higher than W.H.O standard, while  sachet water has values of 0.28mg/l and 1.01mg/l. Iron value of borehole water is 1.20mg/l, while sachet water is lower with a value of 1.12mg/l. Nitrate is 0.39mg/l in borehole water which is lower than sachet water which has 0.41mg/l. Borehole water is lower in Zinc with a value of 0.41mg/l while sachet water has a higher value of 0.44mg/l. Borehole water has a phosphate value of 5.21mg/l while sachet water has a lower value of 4.02mg/l. Magnesium is higher in borehole water with a value 1.47mg/l, while sachet water has 0.93mg/l. The parameters analyzed most generally conform to the W.H.O standards for drinking water.

Water is a universal solvent, which consist of hydrogen and oxygen atoms. Chemically, it could be defined as a chemical substance with two atoms of hydrogen and one atom of oxygen in each of its molecules; hence the molecular formula is H2O. It is formed by the direct reaction of hydrogen with oxygen;

                  2H2 + O2                  2H2O

         Water is colourless, odourless and tasteless liquid in its pure form. It is an inorganic substance that occurs in three states; liquid gaseous and solid states1. Water covers 71% of the earth surface. On earth , it is found mostly in oceans and other large water bodies with 1.6% of water below ground in aquifers and 0.001% in the air as vapour clouds (formed from the solid and liquid water particles suspended in air), and precipitation2.  Oceans hold 97% of surface water, glacier and polar ice cap 2.4% and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earths water is contained within biological bodies and manufactured products. Water on earth moves continually through a cycle of evaporation, transpiration, precipitation and runoff, usually reaching the sea. Overland, evaporation and transpiration contributes to the precipitation. Clean and fresh drinking water is essential for human and other life forms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world3, 4. There is a correlation between access to safe water and GDP, per capita5. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability6.

          As water is heated from OOC, it contracts until 4oC is reached and then begins the expansion which is normally associated with increasing temperature. The viscosity of water decreases ten folds as the temperature is raised from OOC to 100 OC, and this also is associated with the decrease of ice like character in the water as the hydrogen bonds are disrupted by increasing thermal agitation. The electrical conductivity of water is at 1,000,000 times larger than that of most other non-metallic liquids at room temperature. The current in this case is carried by ions produced by the dissociation of water according to the reaction;

        H2O                               H+  +    OH-

           These products recombine completely to form water vapour, also undergoes most of the chemical reactions of liquid water and at very high concentration even shows some of the unusual solvents properties of liquid water. Above 3740C, water vapour may be compressed to any density without liquefying, and at a density as high as 0.4glcm3, it can dissolve appreciable quantities of salt7.

Water naturally exists in three main sources; rain water, ground water and surface water.

Rain water is naturally the purest source of water but as it gets down it absorbs compounds from the atmosphere. Its main components are chlorides, nitrates, sulphates, sodium, potassium and ammonia. The concentration can vary from 0.1 to 10uglml. The rain can be collected from roofs and prepared water sheds which could assist in polluting and making it one of the most unfit sources of water for drinking8.