الفهرس 
Water Treatment
Water – Related DiseasesOnly 14 pages are availabe for public view
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Abstract
Water is second to oxygen as being essential for life. People can survive days, weeks, or even longer without food, but only about four days without water. It plays a role in nearly every function of the body.
The number of different types of pathogens that can be present in water as a result of contamination with human or animal feces is very large and it is not possible to test water samples for each specific pathogen. Therefore, scientists and public health officials typically choose to monitor non pathogenic bacteria that are usually associated with pathogens transmitted by fecal contamination; but are more easily sampled and measured. These associated bacteria are called indicator organisms.
Although coliphages are not known to be hazardous to human beings, they are important organisms for assessment of the safety of treated drinking water supplies because their absence has proven to be a reliable indication of acceptable general hygienic quality.
The detection of coliphage has been of increasing interest since it has become clear that bacterial monitoring of water may not adequately indicate the presence of viruses in that water. Detection of human enteric viruses in water, however, is beyond the capability of most water laboratories. Such detection traditionally has required the use of cell culture techniques. These techniques are expensive, require skilled personnel and have been time and labor-intensive. Coliphage assays on the other hand are relatively inexpensive, easier to perform with trained personnel and yield overnight results. Coliphage assays have been proposed as an alternative to human virus assays as an indicator of the viral quality of water.
The present study aimed to study coliphage and coliforms as indicators of fecal pollution in potable and non potable water in Alexandria.
The study was carried out during 12 months, from the beginning of August 2006 to the end of July 2007, on a total of 600 water samples (264 non potable and 336 potable samples). These samples were collected monthly.
Non potable water samples:
1) A total of 108 water samples were collected from 9 points on Mahmoudia Canal. (12 samples from each point)
2) A total of 108 water samples were collected from 9 points on Noubaria Canal. (12 samples from each point)
3) A total of 48 water samples were collected from intakes of the four representative WTPs (Sharqy, Manshia, Seiouf and Noubaria) 12 samples from each WTP.
Potable water samples:
a. A total of 48 water samples were collected from four different WTP outlets (Sharqy,
Manshia, Seiouf and Noubaria).
b. A total of 288 water samples were collected from six sites of DS.
Water samples were aseptically collected in 500 ml sterile bottles. These bottles contained sodium thiosulphate for potable water samples.
The water samples were directly transferred to the laboratory and examined within 1-6 hours of collection. Each sample was vigorously shaken and subjected to microbiological, physical and chemical examination.
Microbiological examination:
1) Enumeration of HPC using standard pour plate method.
2) Enumeration of TC and TTC using MTF technique.
3) Enumeration of TC and TTC by MF technique using M-Endo and M-FC medium.
4) Enumeration of TC and E. coli by MF technique using (CECM).
5) Detection of coliphage using ARCAT, LCPA and mLCPA techniques.
The results of this study can be summarized as follows:
1) According to Egyptian guidelines, out of 336 examined potable water samples 3% from DS. were unacceptable as regards TC parameter by all examined methods.
2) The percentage of coliphage detection by LCPA was higher than that by ARCAT (95.5%, 92%) respectively.
3) A significant agreement was revealed between coliform counts (TC, TTC and E. coli) and coliphage counts in non potable water from of Mahmoudia, Noubaria Canals and intakes of WTPs.
4) The HPC had significant direct moderate correlations with all microbiological parameters (r = 0.59, 0.55, 0.42 for TC, TTC and coliphage respectively).
5) The highest TC count (≥ 9x103/100 ml) recovered from the examined samples was (87.9%) using chromogenic medium compared to 25% and 25.8% using MTF method and M-Endo medium respectively.
6) The chromogenic medium recovered 6.6 times TC as M-Endo medium.
7) Out of the 264 non potable water sample examined by MTF, 69(26.1%) had TTC count ≥1.3×103/100 ml. The corresponding figure for samples examined by MF method using M-FC medium was 84(31.8%) and samples examined by MF using chromogenic medium was 202(67.5%) respectively.
8) The coliphage had a direct correlation with TC by all methods in the examined non potable water samples(r =0.5, 0.57 and 0.19 by MTF, MF using M-Endo medium and MF using chromogenic medium respectively).
9) Regarding the level of coliphage, TTC and E. coli by all methods among non potable water samples, a direct moderate correlation was revealed (r = 0.55, 0.57, 0.34 by MTF, MF using M-FC medium and E. coli by MF using chromogenic medium, respectively).
10) The mean values of pH at all points on Mahmoudia and Noubaria Canals were nearly the same (pH= 7.9 to 8.2). The highest mean values of temperature in Mahmoudia and Noubaria Canals were 24.3 and 23.4°C, respectively in autumn.
11) There was a non significant correlation between all microbiological parameters and temperature. The same was true for the pH, except for TC by MF using chromogenic medium which showed a significant correlation.
12) There was a significant inverse correlation between EC and TC and TTC while there was a non significant inverse correlation with coliphage.
13) There were significant direct correlations between TC, E. coli and (ammonia, nitrate). Also there were significant direct correlations between TTC, coliphage and ammonia, nitrite.
14) In Mahmoudia Canal, the highest mean value of ammonia (2.26mg/L) and the highest mean counts of HPC, TC and TTC were at Zarkon. Also regarding nitrite and nitrate, the picture was nearly the same as ammonia.
15) In Noubaria Canal, the highest mean values of ammonia, nitrite and nitrate and the highest mean counts of HPC, TC and TTC were at Janakleese Bridge.
16) In Mahmoudia Canal, there was a statistically significant difference between turbidity, conductivity, ammonia, nitrite and nitrate mean values and site of collection as well as with seasons, whereas the differences of pH mean value was statistically significant only among seasons.
17) In Noubaria Canal the difference of turbidity, ammonia and nitrite mean values were statistically significant among seasons, whereas the differences of turbidity, conductivity and nitrate mean values were statistically significant among sites of collection.