Analysis of Physical and Chemical Parameters in Ground Water Used for Drinking around Konso Area, Southwestern Ethiopia

Abstract

To improve water quality, there should be a mechanism of keeping safe water source from chemical contaminants in an effective and protective way through the application of regular check up and with interventions by taking exact measure periodically before it is supplied for usage. The intention of this research work is to determine the level of common cations, anions, heavy metals and physical parameters in drinking water supply system in konso and its surrounding area, Southwestern of Ethiopia. Water samples were collected from 23 different locations in the area where there is hand pump or motorized supply system that are used for drinking purpose. Collected samples were analyzed for physicochemical parameters including total alkalinity, Temperature, pH, Electrical Conductivity, Total dissolved solids, Turbidity, Alkalinity, Total hardness and Total suspended solid. Common cations (Li + , K + , Na + , Ca 2+ and Mg 2+), Common anions (NO3 − , SO4 2− , PO4 2− , F − and Cl −) and Heavy metals (Pd, Ni, Mn, Pb, Co, Zn, Cu) were analyzed. The obtained results were compared with some national and international standards or guidelines for drinking water. Accordingly, the results obtained show that most of the physical and some common ions and heavy metals were within the accepted range of the guideline recommended by WHO. In addition to this, some parameters are at alarming state as compared to the WHO standards for drinking purposes, thereby suggesting the need for treatment and precautionary measures for use of the particular ground water. Water is one of the most important and most precious natural resources. It is vital to man's existence and without it, there would be no life on earth. The earth holds approximately 1.4 × 10 9 cubic kilometers of water in the form of oceans, seas, rivers, lakes, ice, etc.; but only 3% of the total available water resources are in the form of fresh water found in rivers, lakes, and groundwater. The fresh water that is needed for a clean water supply is limited, and demand far exceeds the available supply due to increasing population and industrialization [1,2]. A clean water supply is one of the key indicators for development in any country; however, the situation of most African countries is not encouraging because of more than 300 million people in Africa living in water scarce environments [3]. The availability of water resources and the amount of freshwater continue to decrease time to time in Africa. In Sub-Saharan Africa, the water requirements for major domestic and industrial purposes are usually not met. The need to determine the quality of public water supply has been intensified as a result of an increase in water pollution on a global scale caused by increasing population, urbanization and industrialization [4]. All these major causes have rampantly deteriorated the quality of water the world over. This has resulted in the decrease in the quality of drinking water available and has also caused the decline of resources from our marine sources as the runoff water from the land is ultimately destined for the seas [5]. Groundwater is an important source of drinking water for humankind. It contains over 90% of the fresh water resources and is an important reserve of good quality water [6] and it is also used for agricultural, industrial, household, recreational and environmental activities all over the world [7]. In the last few decades, the ground water potential and its quality level in major cities and urban center's is getting deteriorated due to the population explosion, urbanization, industrialization and also the failure of monsoon and improper management of rain water [8]. The chemical composition of groundwater is a measure of its suitability as a source of water for human and animal consumption, irrigation, and for industrial and other purposes. The ground water quality is normally characterized by physical characteristics, chemical composition, and biological parameters. These quality parameters reflect inputs from natural sources including the atmosphere, soil and water rock weathering, as well as anthropogenic influences of various activities such as mining, land clearance, agriculture, acid precipitation, and domestic and industrial wastes. These parameters change widely due to the type of pollution, seasonal fluctuation, ground water extraction, etc. Monitoring of water quality levels is thus important to assess the levels of pollution, to assess its potability for human consumption, also to assess the potential risk to the environment and for the sustainable management of these resources [8-11]. Groundwater usually contains dissolved mineral ions which can affect the water's usage depending on the type and concentrations of the ions involved. Major cations and anions found in groundwater include Calcium, Manganese, Chromium, Cadmium, Copper, Cobalt, Zinc, Lithium, Sodium, Potassium, Nitrate, Sulphate, Bicarbonate and Chloride. Non-ionic constituents such as oxides, phenols, synthetic detergents, dissolved O2 and CO2 are also found in groundwater. These