Physical and Chemical Status of Drinking Water from Water Treatment Plants on Greater Zab River

Abstract

The contamination of surface waters through human activities has been intensified over the past years as the population density has increased. In order to ascertain the drinking water quality of Greater Zab river in Erbil, Kurdistan, Iraq, for human consumptions, water samples were collected from three water treatment plants (WTP) on that river. The following water quality parameters were determined which were chosen as the major indicators namely PH, Total Dissolved Solid(TDS), Electrical conductivity(EC), Total Hardness(TH), Cl-, F-, Na + , K + , Ca +2 , Mg +2 , NO3-, SO4-2 , PO4-3 and the concentration of eight heavy metals (Fe, Pb, Hg, Zn, Cd, Ni, Cu, and Ag. Concentrations of the metals in the water samples were determined by flame atomic absorption spectrometry. The research Results showed that efficiency of filtration unit of the three WTPs was: Efraz 1> Efraz 2> Efraz 3. Most of the parameters analyzed in this study were within the guidelines given by WHO or US EPA for drinking water while few others were not. @ JASEM Water quality is a growing global concern. Polluted water and inadequate sanitation kill two children every minute worldwide. Water quality is the physical, chemical and biological characteristics of water in relationship to a set of standards. The primary uses considered for such characterization are parameters which relate to drinking water, safety of human contact, and for health of ecosystem. Interest in water analysis is due to the enormous importance of water to all categories of living things. It is necessary for the healthy development of man, animals and plants (Naveen, 2007). According to the Australian drinking water guidelines: drinking water must not contain chemicals, inorganic substances or organisms that may be harmful to human health. Drinking water should also be at reasonable temperature and be free of unappealing odours, taste and colour .The guideline defines drinking water as water which is safe to drink over a life time that is, it constitutes no significant risk to health. Investigations of the quality of drinking water have been continuously performed by researchers (Maria et al, 2009; Jos, 2009) around the world with rapid urbanization; the chemical aspects of water quality have become a cause of increasing concern as toxic chemicals in industrial effluents pose a high risk to human health. Two surveys of consumer satisfaction with drinking water quality conducted in Tiwan (Chung, 2007), in both surveys, the main reasons that respondents did not drink tap water was "water sources are inappropariate" and "unpleasant mouth feel". A study conducted on the level of inorganic elements and heavy metals (Na, Mg, Fe, Ni, Co, Cu, Cd, Pb and Zn) in Kallar Kahar lake (Furhan, 2005), indicated that the concentration of the studied elements were not within the safe limit at the sampling sites throughout the studied period and the Kallar Kahar lake is not suitable for drinking, farming and agriculture. This study was aimed to evaluate the quality of Greater Zab river water for drinking and irrigation purposes. Also to determine the physical, chemical and the dissolved concentration of trace metals in drinking water from the three (WTP) on Greater Zab at Efraz village and to qualify the efficiency of their filtration unit. MATERIALS AND METHODS Reagents and Solutions Analytical reagent grade chemicals were employed for the preparation of all solutions. Freshly prepared deionized water was used in all experiments. Apparatus Prior to analysis, all instruments were calibrated according to manufacturer's recommendations. PH was measured by using Portable PH-meter (HANNA instrument model PHB) with combined electrode. EC was determined by conductivity meter Hi8314. Sodium and Potassium ions were measured by Flame photometer model Jenway PEP7 England (UK).Turbidity was measured by turbidity meter Hf Scientific, inc. model BRF 15CE. Fe, Pb, Hg, Zn, Cd, Ni, Cu, and Ag were determined by Flame Atomic Absorption Spectroscopy. Experimental Sites Erbil is the capital of Iraqi Kurdistan and situated in the northeast of Iraq. The Greater-zab river(Bahdinan river) is the only source of surface water in Erbil city for drinking and other purposes(Shuokr, 2007). Three WTPs were constructed on this river at Efraz village. Water samples were gathered from three (WTPs), on five different locations were indicated as sampling site.