The purpose of this report is to give the reader an understanding in how drinking water quality differs from different water sources and how water quality changes during different scenarios (exposure to environment and temperature differences). At first, water quality requirements (standards) and theory are explained for assessing which factors are relevant to test, both chemical and microbiological. Several parameters were chosen to be tested in the empirical part, taking into consideration the possible effects on human health and the availability of testing. Four different scenarios were established (water exposed to different temperatures and the environment) and four different bottled water brands and tapped water from one source were selected for testing. These scenarios, or treatments, were chosen to reflect real life situations, such as opening a bottle, drinking a small amount and leaving it at a cold temperature (5 degrees) for a long duration (3 days). Testing the chosen parameters four different techniques were used – Gran titration, ion chromatograph, nutrient kits and standard plate count (Kimtal in Danish). The results show different outcomes for the different types of water and some of the results deviate for each scenario. The pH-value and hydrogen carbonate (gran titration) deviate between the brands (source), for example the pH values range from lowest at 6.8 to highest at 7.7, but experienced no significant changes in all water treatments. This is also the case for the chemical analysis (ion chromatograph and nutrient kits). For instance, the amount of sodium in the brand Evian is at 10 mg/l where the brand Kildevæld has an amount of 48 mg/l. The result obtained from the plate count test shows a general picture of how bacteria grow faster when the water has been exposed and is kept at a warm temperature. In some cases, the values of the different elements noted on the bottled water labels deviate from the values obtained in the experiments, such as pH and magnesium, which questions whether or not the information on the bottled labels is reliable. From our test results we can conclude that the quality varies significantly for each source, where changes in quality throughout the different treatments only have a significant effect on microbiology.
|Uddannelser||Basis - International Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis|
|Udgivelsesdato||15 jan. 2008|
|Vejledere||Gary Thomas Banta|
- Quality Differences During Exposure
- Drinking Water Quality
- Water Sources Differences
- Exposure to Environment