Physical Characteristics of Water Used by Haramaya University and the Effects of Heating and Cooling on the Amount of Extracted Solids

Abstract

This study was conducted at Haramaya University to assess the levels of physical water quality parameters in water samples collected from four wells, the main water reservoir and taps delivering water to three zones of the campus. The physical water quality parameters examined were total solids, dissolved solids, suspended solids, turbidity, pH and electrical conductivity. Besides, heating and cooling temperatures at which most of the solids could be extracted were also tested. The results from the wells were compared pair-wise and likewise the results of each water sample from the three zones with the water sample from the main reservoir. One of the four wells (W3) and two of the distribution zones (Z1 and Z2) had total solids in excess of 1000 mg L-1. All the sampling sites showed dissolved solids in excess of 500 mg L-1. Suspended solids at all the sites accounted for less than 25% of the total solids. One of the wells (W3) showed significant difference (P < 0.05) from the rest in most of the physical parameters. Except this well, the rest were within the WHO limits with regard to total, dissolved and suspended solids. Two distribution zones (Z1 and Z2) showed significant differences (P < 0.05) from the reservoir in most of the physical parameters. Both heating and cooling showed effects on the amount of solids extracted from the water. From the temperatures tested, heating the water above 80 0C and cooling it to less than 15 0C resulted solid extraction of higher solids. Heating and cooling at temperatures close to these temperatures removed most of the cations that accounted for water hardness.

Keywords: Total Solids; Dissolved Solids; Suspended Solids; Turbidity; Electrical Conductivity