Abstract: The present study was conducted to analyze the underground water of Faisalabad city Sector II to determine its suitability for domestic consumption owing the scarcity of municipal supply water. The water of all the selected areas have high values of chemical oxygen demand (COD) showing organic pollution. Areas along Narwala road especially Raza Abad, Gulshan colony, Ghulam Muhammad Abad, Chur Majra and Bole-di-Jhugi have very high values of chlorides and dissolved solids while the areas along Sargodha road have somewhat permissible results.
Introduction
The quality of water is of vital concern for mankind since it is directly linked with human welfare. It is a matter of history that faecal pollution of drinking water caused water borne diseases which wiped out entire population of cities (Dey, 1989).
Faisalabad is densely populated city and due to tremendous increase in population growth, the demand for water has been increasing every year. Faisalabad has a lot of textile mills and wastes from textile- manufacturing processes could be generated from the washing out of impurities in the fibers, as well as in discarding of chemicals used in the processing of fibers. Generally these wastes have been organics, have a high COD and are extremely alkaline.
Water used for drinking, cooking and food processing should have no odour, no colour and essentially no turbidity (Katyal and Satake, 1990). Too much oxygen in water tends to increase the corrosion of metals and water pipes. The potable water contaminated by the presence of some inorganic ions produces harmful effects. Excess of calcium causes renal stones and its deficiency can cause osteoporosis and rickets. Excess of manganese can cause renal failure(Sawyer et al., 1994).
Nitrate poisoning brings about a condition called methemoglobinemia, resulting from changes in the hemoglobin of the red blood cells that reduce their capacity to carry oxygen. Water contaminated by zinc causes vomiting, renal damage and craps etc (Tyagi and Mehra, 1990). Calcium and magnesium are responsible for hardness of water.
Keeping in view the associated hazardous effects connected with either deficiency or enrichment of cations, anions and some metals in the potable water, the present project is designed to asses the quality of underground water of Faisalabad Sector II (areas along Narwala and Sargodha road).
Materials and Methods
A total number of sixty different samples were collected from twenty different sampling points of Faisalabad City Sector Il (areas along Narwala and Sargodha road) with three replicates (Table 1).
| Table 1: | Sample locations |
The samples were analyzed for various physico-chemical parameters like pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), Hardness, some anions (CI‾, NO3‾, HCO3‾ , CO32‾, SO42‾) and some cations (Na+, K+, Ca2+, Mg2+, Fe2+, Mn2+, Zn2+). pH was determined by using pH meter while electrical conductivity was determined by conductivity meter (Greenberg et al., 1992). Evaporation method was employed for determination of total dissolved solids (TDS). Dissolved oxygen (DO) and chemical oxygen demand (COD) was determined by DO meter and COD apparatus directly (Greenberg et al., 1992). EDTA titrimetric method was used to analyze hardness of water (Greenberg et al., 1992). Chloride, carbonate and bicarbonate were determined by titration methods using AgNO3 and H2SO4 respectively (Rump and Krist, 1992).
Turbiditimetric method was used to estimate sulphate in water while calorimetric method was used to analyze nitrate (Greenberg et al., 1992). Flame photometer was used to determine Na+ and K+ while Ca2+ and Mg2+ were estimated by EDTA titrimetric method (Greenberg et al., 1992). Iron, manganese and zinc were determined by atomic absorption spectrophotometer (Greenberg et al., 1992).
Results
The pH of the samples appeared to lie between 7.2-7.8 which is well within permissible limit. The variation in conductivity revealed a wide range of values from 710 to 7150 μmho/cm. Total dissolved solids (TDS) values of the samples fell within the range 390.5 to 3932.5 ppm. The minimum TDS value was shown by sample 1 (Dhobi Ghat while maximum value was in sample 6 (Raza Abad).
| Table 2: | Analytical results of physico-chemical parameters |
| Table 3: | Statistical analysis (t-Test) of physico-chemical parameters |
| N.D = Not detected, NS = Non-significant, * = Significant, ** = Highly significant | |
The observed values of dissolved oxygen were within the limit 4.97 to 7.11 ppm in which only 35 percent of the samples were within the standard limit (6 ppm). The values computed for chemical oxygen demand (COD) ranged between 35.55 to 48.76 ppm and total hardness values lie between 120 to 290 ppm. The chloride values varied between 44 to 1630 ppm (Table 2, 3). The concentration of nitrate and sulphate were appeared to be within permissible limit of 45 ppm and 250 ppm respectively. Carbonates were absent while all the samples had bicarbonate values above the permissible limit 250 ppm (Table 4, 5). All the water samples had alarmingly high values of sodium and potassium. The concentration range of Na+ ion in water samples was from 60 to 930 ppm. Calcium and Magnesium concentrations were within the safe limit of 100 ppm and 50 ppm respectively. Manganese was found to be absent in all the samples while the concentrations of iron and zinc were within the safe limit of 0.3 ppm and 5 ppm respectively (Table 6, 7).
Discussion
It is revealed from the results that all the water samples have pH value within the permissible range (6-8.5). pH provided the information about acidity or alkalinity of water (Katyal and Satake, 1990). It provides a mean of clarifying and for collecting other characteristics or behaviour such as corrosive activity (Ghandour et al., 1985). As eye irritation and exacerbation of skin disorders have been associated with pH value greater than 11 (Anonymous, 1993). So regarding the pH value, all the samples are within safe limit, The results show that electrical conductivity (EC) values in all the samples are much higher than permissible limit which predicts the presence of excess of minerals and dissolved matter in water. Water with EC higher than 1500 ,umhos/cm is harmful for human health (Tyagi and Mehra, 1990). As shown by results only 35 per cent of samples have DO value within the standard limit. However excess of dissolved oxygen might not be harmful for health. Usually underground water lacks dissolved oxygen (Campbell and Bower, 1996). Very low concentration of dissolved oxygen supports the growth of anaerobic microorganisms and limits the purification capacity of the water (Rump and Krist, 1992).
| Table 4: | Analytical results of Anions (ppm) |
| Table 5: | Analytical results of Anions (ppm) |
| N.D = Not detected, N.S = Non-significant, * = Significant, ** = Highly significant | |
| Table 6: | Analytical results of Cations (ppm) |
| Table 7: | Statistical analysis (t-Test) of Cations |
| N.D. = Not detected, N.S. = Non-Significant, * = Significant, ** = Highly significant | |
Water samples, containing very high value of COD present a sure sign of organic contamination in water, making it harmful for human consumption. The values obtained for total dissolved solids (TDS) show that most of the samples have TDS much above than standard value which indicates that water is impalatable for drinking. The presence of high levels of TDS is objectionable to consumers owing to excessive scaling in water pipes, heaters, boilers and household appliances (Anonymous, 1993). The test of chloride can be used as a pollution indicator when considered together with other parameters (Rump and Krist, 1992). The permissible limit for chloride is 250 ppm. Excess of chloride ions causes hypertension (Dey, 1989).
Nitrate which is luckily present in permissible limit is the cause of various health hazards. Nitrate poisoning bring about conditions called methemoglobinemia and cyanosis (Tyagi and Mehra, 1990). Sulphate is one of the least toxic anion. The permissible limit for sulphate is 250 ppm. Excess of sulphate causes catharsis, dehydration and gestric intestinal irritation (Greenberg et al., 1992).
The excessive concentration of bicarbonate is responsible for corrosion to metal pipe, boiler, heaters and other household and industrial equipment (Greenberg et al., 1992). Sodium in excess produces a state of alkalosis, high blood pressure and certain other diseases (Anonymous, 1993). Similarly excessive amount of potassium causes cardiac arrest, small bowel, ulcers and dehydration (Katyal and Satake, 1990). Calcium and magnesium are important contributors of hardness of water. The concentration of iron and zinc does not show any damage either to health or economy because they are present only in traces.