JECET; June – August-2013; Vol.2.No.3, 756-768.
Journal of Environmental Science, Computer Science and Engineering & Technology
An International Peer Review E-3 Journal of Sciences and Technology
Available online at www.jecet.org Environmental Science
Research Article
JECET; June – August 2013; Vol.2.No.3, 756-768. 756
Physico-Chemical and Bacteriological assessment of Tap Water Used for Drinking
Purposes in Zabid, Yemen
Mawhoob Noman Alkadasi a*, Abdulbaset A. Zaid b, Abdulrahman S. Najia, Nada Almushafaa and Gamal A. A-Americ
aDepartment Of Chemistry, Zabeed Education Collage, Hudaiadah University, Hudaiada, Yemen.
BPost Graduate and Research Center, Maulana Azad College, Aurangabad (Maharashtra) India
cDepartment of Microbiology, Medical collage Taiz University Taiz Yemen
Received: 12 July 2013; Revised: 2 August 2013; Accepted: 5 August 2013
Abstract: The present study was therefore undertaken to assess the quality of drinking water in some houses of Zabid district. Some physic-chemical and biological parameters were examined from twenty tap water. Among the tested characteristics, temperature values fluctuated between 29.2–29.8 C°, pH values varied between 6.7-8.7, turbidity values differed from 0.15–7.6 NTU electric conductivity values ranged from 338-1150 µs/cm, chloride ranged from 55.4-375.2 mg/l, total hardness contents fluctuated between 120-442 mg/l, total dissolved solids ranged from 215-699 mg/l, nitrate ranged from 0.01-0.62 mg/l, Phosphate ranged from0.01-0.15 mg/l, sulphate contents fluctuated between 68-171 mg/l, calcium contents fluctuated between 22.12-80.12 mg/l, magnesium level varied between 22.12-62.22 mg/l and dissolved oxygen ranged from 3.80-6.05. Similarly, E.Coli count ranged from 0.00-3.00 cfu/ml, so that the investigated samples were suffered from faecal contamination. The study revealed that the most of chemical parameters of tap water sources did not meet the permissible World Health
JECET; June – August 2013; Vol.2.No.3, 756-768. 757 Organization (WHO) levels. Examining exceedence above the WHO standards, it was revealed that most of the samples contained pH, levels above allowable WHO limits. It was recommended that tap water sources for domestic use should be protected from pollution sources.
Keyword: Assessment, tap water, drinking purpose, Zabid, Yemen.
INTRODUCTION
Water is of the most important of all natural resources. It is vital for all living organisms. Accessibility and availability of fresh clean water is a key to sustainable development an essential element in health, food production and poverty reduction. In those days people on globe are under tremendous threat due to undesired changes in the physical, chemical and biological characteristics of air, water and soil. Due to increased human population, industrialization, use of fertilizers and man-made activity water is highly polluted with different harmful contaminants. Natural water contaminates due to weathering of rocks and leaching of soils, mining processing etc. It is necessary that the quality of drinking water should be checked at regular time interval, because due to use of contaminated drinking water, human population suffers from varied of water borne diseases.
Drinking water is a major source of microbial pathogens in developing regions, although poor sanitation and food sources are integral to enteric pathogen exposure1,2. The lack of safe drinking water and adequate sanitation measures lead to a number of diseases such as cholera, dysentery, salmonellosis and typhoid and every year millions of lives are claimed in the developing countries3. Moreover septic tanks, open dumps, in proper constriction latrines and surface impoundments are the most common sources for sewage contamination, so that regular examination of water quality for the presence of pathogenic organisms, chemicals and other physical contents must be conducted to provide information on the level of the safety of water4. Although modern microbiological techniques have made possible the detection of pathogenic bacteria, viruses and protozoa in sewage and sewage effluents, it is not practical to attempt to isolate them as a routine procedure from samples of drinking water5. The aim of this study was to determine the physicochemical and microbiological quality of tap water from Zabid district of Alhudaida city and to evaluate their suitability for drinking purposes, in accordance to the WHO standards for drinking water.
MATERIAL AND METHODS
Location of Study Sites with Map: Zabid is one of the important districts of hudaiadah city of Yemen. The geographical location of Zabid district lies between the latitude of 14° 12' N and longitude of 43° 19'E. It has got an elevation of 100 m. Zabid occupies an intermediate position between the Red Sea in the west and mountains chain to the east, where away from each other a distance "25 km and also located between the two important agricultures valleys Zabid valley in the south and Rmaah valley in the north of the zabid district and about 90 km south of Hudaiadah . The climate of zabid is extremely heat and humidity in the summer and tends to moderate in winter. It is fall within the belt of high humidity and brightness solar. Location of
Sample collection: Composite water samples were collected from twenty tap water sources. Two sets samples, each of 500 ml, were collected from each source; one set of physicochemical analysis and the other set for microbial analysis. Each sample was collected in either high density polyethylene bottles (physicochemical analysis) or sterilized glass bottles(microbial analysis) with the cap securely
JECET; June – August 2013; Vol.2.No.3, 756-768. 758 tightened .Standard procedures for collection , handling and preservation6-8 were followed to ensure data quality and consistency. The sampling points are shown in Table 1.
Chemical Analysis: The following physicochemical parameters were determined at site of collection, pH, temperature and DO fixation (Table 1).Other water quality parameters was analyzed in the laboratory using standard procedures9.
بf
Figure-1: Location of study sites: Zabid –Yemen
JECET; June – August 2013; Vol.2.No.3, 756-768. 759 Table- 1: Physico-chemical and biological methods
RESULT AND DISCUSSION
The physico-chemical analysis ( Water temperature, pH, Turbidity, Electrical conductivity, Total hardness, calcium, magnesium, DO, chloride, nitrate, phosphate and sulphate ) to all twenty tap water sample from four different sites are presented in Table 2.
Water temperature: Temperature is biologically an important factor which plays a vital role in proper functioning of all living things. Microbial load in water will be lower if temperature10 remains below 15°C. Examination of tap water for temperature was ranged 29.3 C°-29.8 C° Table2.
Temperature examination revealed a little fluctuation in results between 29.3 C°-29.8 C° highest value was determined in S1, lowest was found in S13water sample water (figure2). Variation in temperature might be due to the rate of chemical reactions and the nature of biological processes taking place in aquatic system11. WHO has provided no guideline and standards for temperature of drinking water, however, it has been suggested that the temperature of drinking water must be less than 15°C because warm water holds less oxygen content.
Unit Instrument used
APHA, 1995 Parameters
Sl. No.
°Χ Mercury thermometer
Direct Temperature
1
- pH meter
Electrometric pH
2
Digital Nephelo turbidity NTU unit model 132 Systronics Photometric
Turbidity 3
µMhos/cm Conductivity meter
Electrometric EC
4
mg/L-1 -
Evaporation TDS
5
mg/L-1 Titration
Argentometric Chloride
6
mg/L-1 Titration
EDTA titrimetric TH
7
mg/L-1 UV-visible spectrometer
Spectrophotometer Nitrates
8
mg/L-1 UV-Visible spectrophoto-
meter method Ammonium
molybdate Phosphates
9
mg/L-1 Titration
Winkler’s DO
10
mg/L-1 Titration
Titrimetric Calcium
11
mg/L-1 Titration
Titrimetric Magnesium
12
mg/L-1 UV-Visible
spectrophotometer method
Barium chloride Sulfates
13
IDEXX Quanti-
Tray/2000 E. coli/100 ml
14
JECET; June – August 2013; Vol.2.No.3, 756-768. 760 Figure 2: water temperature level in all tap water
pH values: The pH values of most tap water samples were slightly basic (pH 6.7.6-8.7) as shown in Table 2. Highest pH value was determined in S18 and lowest value was found in S17 water sample (Figure3). Water having pH at around 8.1 is helpful for successful chlorination while supply pipes are also safe from corrosion. On the basis of pH values, tap water can be regarded as not suitable for drinking, as the values not obtained met the permissible levels as recommended by WHO. The higher pH values observed suggests that carbon dioxide, carbonate-bicarbonate equilibrium is affected more due to change in physico-chemical condition12.
Figure 3: pH level in all tap water
Turbidity: Turbidity represents an important aspect of water quality. It is deemed as the cloudiness of a liquid as a result of particulate matter being suspended within it. The turbidity measured on all the samples were shown in figure 4. The turbidity was ranged between 0.2 - 7.6 NTU. According to the World Health Organization (WHO) 13 stated drinking water is best consumed with NTU less than 1 for health purpose. The results for these turbidity analyses were shown in Table 2. WHO suggest that the appearance of water with a turbidity of less than 5 NTU is usually acceptable to consumers, although may vary with local circumstances. The consumption of highly turbid water may constitute a
JECET; June – August 2013; Vol.2.No.3, 756-768. 761 health risk as excessive turbidity can protect pathogenic microorganisms from the effects of disinfectants, and also stimulate the growth of bacteria during storage 14.
Figure 4: Turbidity level in all tap water
Electrical conductivity: Electrical conductivity (EC) is the calculation of water tendency to pass electric current through it. It indicates the total amount of dissolved salts. EC values for drinking water depends on the concentration of dissolved salts and ionic particles through which electric current passes, it will be higher with more electrolytes in water 15. EC values in all selected tap water sample were ranged 448 µs/cm.00-1151.00 µs/cm, showen in Table 2. Maximum value for EC was found in S5, while the lowest value was observed in S2 (Figure 5). The S5 tap water has highest value of EC, which might be due to presence of high concentrations of dissolved salts and ionic particles then others tested samples of different localities. According to WHO, electrical conductivity of drinking water must not exceed 1400 µs/cm. Thus the EC values analyzed for the samples under investigation were within the prescribed standards of WHO.
Figure 5: Electrical conductivity level in all tap water
JECET; June – August 2013; Vol.2.No.3, 756-768. 762 Table- 2: Variation of physico-chemical and biological parameters
Total dissolved solid: TDS is the calculation of inorganic salts and minute amounts of organic substances present in a water solution. The key compounds are usually calcium, magnesium, sodium, and potassium cations and carbonate, hydrogen carbonate, chloride, sulphate, and nitrate anions.
Outcomes of twenty tap water sample for total dissolved solids ranged 215.00 mg/L, 699.00 mg/L (Table 2). Highest TDS levels were determined in S5 tap water, while the minimum values were found S2 tap water (Figure 6). Water which has TDS levels less than 600 mg/L is regarded as good, while water having TDS more than 1000 mg/L is unacceptable for human consumption. High TDS values are unacceptable because it imparts bitter taste to drinking water and cause scaling of supply pipes. Elevated TDS content also indicates contaminants like iron, manganese, arsenic, sulphates and other elements. Furthermore, increased concentration may also affect individuals who are suffering from kidney and heart problems and also has constipation effects. Furthermore, a value higher than 1000 mg/L results in excessive scales in water pipes, heaters, boilers and household appliances16. TDS values of S5, S6 andS14 tap water were higher as compared to other samples which might be due to the presence of higher amount of calcium, magnesium, and other cations and anions Figure7.
However all the parameters tested were following the permitted standards of WHO.
Sl No.
WT pH EC
TUR TDS
DO TH
Ca2+
Mg2+
NO3
SO4 -
PO4 -2
Cl E.coli
S1 29.8 8.3 558 3.5 345
3.8 380 68.11 40.12
0.62 171
0.15 375.2 3
S2 29.4 8.2 338 3.3 215
5.7 442 80.12 62.22
0.02 104
0.02 70.6
0
S3 29.4 7.9 897 6.7 541
5.15 220
58.22 35.21
0.05 113
0.02 80.2
0
S4 29.5 7.8 850 2.1 506
4.4 410 72.12 40.12
0.12 130
0.06 143.2 1
S5 29.4 7.2 1151 7.6
699 5.4 440 79.13 55.16
0.02 105
0.02 75.6
0
S6 29.6 6.8 989 1.2 608
4.1 152 33.16 12.66
0.18 150
0.07 210.2 2
S7 29.5 7.1 449 0.15 276
4.5 283 62.12 38.12
0.12 125
0.06 140
1
S8 29.4 7.1 825 2.7 501
5.3 216 55.12 21.93
0.04 110
0.02 77.9
0
S9 29.5 7.9 600 7.1 376
5 121 26.22 10.11
0.05 116
0.04 111.2 0
S10 29.7 8.4 715 1.25 451
4 130 30.15 10.22
0.31 162
0.1 245.1 2
S11 29.5 7.4 544 1.7 329
4.7 142 32.21 11.88
0.1 120 0.04 120.8 0
S12 29.6 8.1 713 1.15 429
4.15 200
45.22 18.22
0.15 141
0.06 193.1 2
S13 29.3 7.9 699 0.75 426
6.05 202
46.18 20.22
0.01 86
0.01 55.4
0
S14 29.6 7.3 1100 0.2
657 4.15 220
55.15 34.11
0.14 140
0.06 180.5 1
S15 29.6 8.1 815 3.5 489
4.05 162
43.22 15.12
0.25 150
0.07 212.4 2
S16 29.5 8.3 633 3.9 381
4.55 166
44.15 16.11
0.11 122
0.04 123.6 1
S17 29.6 6.7 595 6.5 370
4.15 120
22.12 6.66
0.12 131
0.06 166.2 1
S18 29.5 8.7 925 2.1 576
5 180 45.11 16.16
0.05 118
0.03 110.3 0
S19 29.6 8.4 955 1.3 587
4 200 45.16 18.11
0.3 167 0.09 240.8 2
S20 29.8 7.6 469 1.6 287
3.8 320 66.32 40.11
0.4 167 0.12 291.6 3
Mean 29.5
7.8 741 2.92 452.45 4.6
235.3 50.47
26.13 0.16
131.4 0.06
161.2 1.05
Min.
29.3 6.7 3
0.15 215
3.8 120 22.12 6.66
0.01 86
0.01 55.4
0
max 29.8 8.7 1151 7.6
699 6.05 442
80.12 62.22
0.62 171
0.15 375.2 3
JECET; June – August 2013; Vol.2.No.3, 756-768. 763 Figure 6: Total dissolved solid level in all tap water
Chloride concentration: The levels of chloride for tap water from different selected tap water are shown in Figure 8. The chloride level was ranged between 55.5 – 375.2 mg/L. The chloride levels in drinking water should not exceed acceptable value of 200 mg/L according to WHO standards. Highest choride levels were observed in the sample S1, S10, S19 and S20 of tap water, while the other sample were following the permitted standards of WHO( Table-2). Higher chloride levels may be due to natural mineral deposits and environmental pollution of those areas.
Figure 7: chloride level in all tap water
Sulphate concentration: The sulphates in water represent agricultural pollution. According to WHO, sulphate of drinking water must not exceed 250 mg/l. Outcomes of twenty tap water sample for sulphate ranged 86-171 mg/L, (Table-2). Maximum value for sulphate was found in S1, while the
JECET; June – August 2013; Vol.2.No.3, 756-768. 764 lowest value was observed in S13 (Figure 9). In all the cases, tap water is not polluted according to their sulphates content.
Figure 8: sulphate level in all tap water
Total hardness: Total Hardness is one of the most important parameter. The major sources of hardness in water are dissolved calcium and magnesium ions from sedimentary rocks whereas minor contribution to the hardness of water is made by ions of aluminium, barium, manganese, iron, zinc etc. The range of total hardness in all the tap water samples was between 120 mg/L to 442 mg/L(Table 2). Highest total hardness value was determined in S2 and lowest value was found in S17 water sample (Figure 10). Total hardness values of S1, S2, S5 andS20 tap water were higher as compared to other samples which might be due to the presence of higher amount of calcium, magnesium, and other cations and anions. However, remain all the tap water samples showed the range of hardness within permissible WHO (300 mg/L) limits.
Figure 9: Total hardness level in all tap water
JECET; June – August 2013; Vol.2.No.3, 756-768. 765 Calsium and magnesium concentration: Values of calcium in the water samples ranged from 22.12 to 80.12 mg/l Table1. For magnesium in water samples the values ranged from 6.66 to 62.22 mg/L (Table 2). Highest calcium and magnesium value were determined in S2 and lowest value was found in S17 water sample (Figure 10, and 11).
Figure 10: Calesium level in all tap water
Figure 11: Magnesium level in all tap water
Nitrate concentration: The nitrates in water result from pollution by urines and agricultural entrants.
The elevated nitrate contents cause the disease known as “Blue-baby” or Methaemo- globinase17. In present study the concentration of nitrate in all tap water samples was ranged between 0.01 mg/L to 0.62 mg/L (Table1 and Figure 12). All tap water samples had nitrate content within permitted WHO (10 mg/L) permissible limit.
JECET; June – August 2013; Vol.2.No.3, 756-768. 766 Figure 12: Nitrate level in all tap water
Phosphate concentration: Phosphorous may occur in water as result of domestic sewage, detergents, agricultural effluents with fertilizers and industrial waste water. High concentration of phosphorous, therefore, is indicative of pollution. Mean concentration of phosphorous ranged between 0.01 to 0.15 mg/L in all tap water tables 2. The lowest concentration was observed at S12, while the highest concentration of phosphorous was observed at S1 figure 13. All tap water samples had phosphorous content within permitted WHO (0.5 mg/L) permissible limit.
Figure 13: Phosphate level in all tap water
Dissolved oxygen: DO is one of the most important parameter. Its correlation with water body gives direct and indirect information e.g. bacterial activity, photosynthesis, availability of nutrients, stratification etc18. In the progress of summer, dissolved oxygen decreased due to increase in temperature and also due to increased microbial activity19-21. However, monitoring oxygen concentration is a convenient way to feel the clause of the aquatic ecosystem explained by22, 23. Variation of dissolved oxygen (mg/l) of different water sample is found to be from 3.8 to 6.02 mg/l Table 2 and Figure 14. The change in oxygen content leads to undesirable obnoxious odour, under anaerobic conditions. Some samples shows less amount of DO than WHO.
JECET; June – August 2013; Vol.2.No.3, 756-768. 767 Figure 14: Dissolved oxygen level in all tap water
Microbial water quality: Outbreaks of disease, often of epidemic proportions can occur if human wastes that are infected with pathogens enter water supplies. Diseases that are transmitted when people drink contaminated water, swim in it, and include cholera, typhoid fever, dysentery, infections, hepatitis and polio. Because it would be practically impossible to test for each of the wide variety of pathogens that may be present, microbiological water quality monitoring is primarily based on tests for indicator organisms. The coliform bacteria count is used to test water for contamination by microorganisms. Coliform bacteria (Escherichia coli) live naturally in the human intestinal tract and the average person excretes billions of them in feaces each day. The term “coliform bacteria” refers to a vaguely defined group of gram negative bacteria that have a long history in water quality assessment. Coliform bacteria are harmless and cause no diseases, but their presence in water is an indication of fecal contamination. If none are found, the water is free from fecal contamination and can be assumed to be free from pathogenic organisms. In the present study the mean of E.coli/100 ml ranged from nil to 3 Table 2 and Figure 15. These results showed negligible contamination from biological effects and the number of E.coli not exceeds recommended limit for human consumption.
Figure 15: E.Coli level in all tap water
JECET; June – August 2013; Vol.2.No.3, 756-768. 768 REFERENCES:
1. N.Ashbolt, J. Toxicology, 2004, 198, 229-238.
2. S.Sharma, P. Sachdeva, J.S. Virdi, Appl Microbiol Biotechnol, 2003, 61, 424-428.
3. S.A.Anon, water bulletin, 2000,26, 18-21.
4. O.E.C.D and WHO, 2003.Improving approaches and methods. http://www.iwapublishing.com/.
5. S.E.Hrudey,P. Payment,P.M.. Huck, R.W. Gillham, E.J. Hrudey, Water Science and Technol.,2003, 47, 7–14.
6. APHA, AWWA, WCPCF.Washington DC. 2012
7. C.U.Anyanwuand, E.N. Okoli.Int.J.Biotech.2012, 11,10868-10873.
8. I.D.Haylamicheal, A. Moges, A..Afr.J.Environ.Sci.Technol. 2012.6(5).
9. S.Jain, A. Monika, J.Chem.Bio.Phy.Sci.2012, 2, 1551-1555.
10. EPA. Environmental Protection Agency 1976.
11. DWAF. 2nd edition, Department of Health and Water Research Commission, 1998.
12. WHO. Guidelines for drinking water quality. Health criteria and other supporting information. 1998, 2.
13. K.R.Karanth, publishing company Ltd, 1987, 725-726.
14. H. Zvikomborero, Physics and Chemistry of the Earth. 2005, 30, 859-866.
15. P.Wright, C.F. Mason, Sci. Total Environ. 1996, 226, 139-156.
16. WHO (World Health Organization, 2011,1.
17. P.Jain, J.D. Sharma, D. Sohu, Sharma, International Journal of Environ- mental Science and Technology, 2005, 2, 373- 379.
18. Premlata, Vikal, An International Journal, 2009, 1, 97-102.
19. D.G.Morrissette and D.S.Mavinic, Journal of Environment, 1978, 6, 1213-1222.
20. B.Moss, Fresh Water Biology 1972, 2, 309-320.
21. R.K.Trivedy, P.K.. Goel, Environmental Publication, Karad, Maharashtra. 1986.
22. H.C.Kataria, H.A. Quershi, S.A. Iqbal, A.K. Shandilya, Pollution Research, 1996, 15, 191-193.
23. Baruh, Bruvold, pergamon press volume, 1970, 4, 331-340.
Corresponding Author: Mawhoob Noman Alkadasi; Department of Chemistry, Zabeed Education Collage, Hudaiadah University. (Maharashtra) INDIA
