Fiji Water Quality: Biology Lab Experiment

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Introduction

Water on Earth is a finite source, and it is considered to be the most abundant compound in the biosphere. Water is on the surface, under the ground is found in vapor form and as precipitation. It is projected that 1.7% of the water on the Earths surface is groundwater, 1.7% is in glaciers and ice caps, and 96.5% is in seas and oceans (Khatri, & Tyagi, 2015). One of the primary chemical characteristics of water is that it dissolves numerous substances, for example, calcium, magnesium, chlorine, and nitrogen oxide. Therefore, water rarely exists in its purest form. Some of these substances that dissolve in water are harmful to its quality and are referred to as pollutants or contaminants. Contaminants are not detrimental to water when present at a low concentration; nevertheless, pollutants can cause harm to water even at a low concentration. The importance of water is critical; however, even more, important is the concept of clean water (Khalifa, & Bidaisee, 2018).

Clean water is a prerequisite for human beings and other organisms. According to Keiser and Shapiro (2019), every individual in the world requires 20-50 liters of clean, safe water every day. Clean water is utilized in drinking, cooking, and simple hygiene, among others. Moreover, there are several infectious agents detrimental to human health that grow in contaminated water, which can result in a number of waterborne diseases such as typhoid, cholera, and hepatitis. Cholera, for instance, has been responsible for 1.8 million deaths globally (Khatri, & Tyagi, 2015). Water quality is measured by evaluating the biological and chemical properties of water against set standards. It is used to assess whether water is suitable for consumption or environment-friendly. Some of the tests used to determine water quality include bacteriological analysis (total coliforms), physicochemical analysis (dissolved oxygen, pH level, nitrates, chloride tests), and aesthetic parameters (color, taste, and odor).

Fiji water is a natural artesian bottled water that is considered the leading premium bottled water brand in the U.S. and the second-largest imported bottled water brand (Fiji Water, 2017). Therefore, Fiji water can be hypothesized to contain minerals and chemicals that fall within the set Environmental Protection Agency (EPA) standards. As I result, I predict that the minerals and chemicals in the Fiji bottled water sample will fall within the EPA standards. Moreover, since Fiji water is among the popular brands in the U.S., it is essential to evaluate whether it is clean, that is, safe for human consumption.

Materials and Methods

Several assays were used in this experiment, and they included the chlorine, ammonia assay, and calcium and magnesium assay. In all these assays, the chloride compound version of each element was used as the positive control, and distilled water was used as the negative control. Other tests comprised the nitrates, pH, Winkler, and Coliscan assays. The Winkler method, also known as the iodometric method, is a titrimetric method for dissolved oxygen analysis. Its principle is grounded on the oxidizing property of dissolved oxygen. On the other hand, the Coliscan assay operates on the principle that for coliforms to ferment lactose, they produce enzyme glucuronidase and galactosidase, which can be identified and indicate the presence of coliforms. All four samples were subjected to similar assays. The materials and procedures used for each assay used are present in the lab manual.

Results

The sources of water samples used in this experiment comprised the Fiji water, Anacostia, rock creek, and pool water. The samples appeared to be clean and fresh. The pH of water from the four different sources was at 7. Furthermore, only Fiji water tested positive for iron, chlorine, and metal ions, while the others tested negative. Third, the concentration of nitrate ranged between 0 and 5ppm. Fourth, the mean concentration of ammonia in water samples ranged from 0 to 0.5ppm, with the rock creek sample having the lowest value and Anacostia having the highest value. Fifth, the quantity of dissolved oxygen is lowest in the Fiji water sample (0.9ppm) and highest in the Anacostia sample. Sixth, all the samples contained metal ions. Lastly, almost all samples had three types of bacteria present; however, the Fiji water sample having a total coliform count exceeding 30.

Table 1: Fiji Water Sample Results.

Chemical Tested For: Fiji Water: Anacostia: Rock Creek: Pool Water: Description of Positive Control Description of Negative Control
Iron
(+ or -)
+    + 
Chlorine
(+ or -)
+    + 
Ammonia
(ppm)
0.25 0.5 0 0.25 4 0
Calcium/
Magnesium
(+ or -)
+ + + + + pink
  • blue
Nitrates
(ppm)
5 0 5 5 N/A N/A
pH
(#)
7 7 7 7 N/A N/A
Types of Bacteria Present 3 3 3 2 N/A N/A
Dissolved Oxygen (ppm) 0.9 1.8 1.2 1.5 N/A N/A

Table 2: Presence of Bacteria.

Your Sample: # colonies/plates
E. coli(dark blue/purple colonies) +30
Other coliforms (pink/red colonies) 0
Noncoliform bacteria (green colonies) 5
White colonies 6

Table 3: Dissolved Oxygen Calculations.

Your Sample: 150 / 1000 x 6 Result: 0.9
Total volume (in mL) Thiosulfate added 150
Total dissolved oxygen in a sample using the following conversion rate 
1 mL of Thiosulfate added = 6 ppm (parts per million)
0.9

Discussion

Both natural and anthropogenic factors influence the quality of water on the Earths surface. In natural causes, water-rock interaction is the primary source of Mg+, Ca+, and HCO3 in groundwater, hydrological factors resulting in run-off, and biological processes within the aquatic environment (Khatri, & Tyagi, 2014). On the other hand, some of the common anthropogenic causes of water pollution include agriculture run-off that carries soils rich in fertilizers, pesticides, and heavy metals in water bodies; agricultural activities such as overgrazed grasslands, poor animal husbandry, and crop farming practices; and discharge of domestic and industrial effluents into water bodies. The before-mentioned natural and anthropogenic factors result in the increase of pollutants such as nitrogen, metal ions, and E. coli in rivers. Combined with the increase in water temperature, the presence of pollutants may lead to chemical reactions that will reduce the amount of dissolved oxygen. This further supports my hypothesis and prediction, which states that the presence of these minerals, nutrients, and micro-organisms indicates water pollution.

The results refuted the hypothesis, which was that the Fiji water was safe for human consumption. This is primarily because it contained high concentrations of E. coli (+30), which exceeded the acceptable level of no bacteria set by the WHO, which is a value between 6.5-8.5 (WHO, 2017). Nevertheless, the concentration of minerals and chemicals in Fiji water fell within the recommended drinking water standards. For instance, the concentration of nitrates in the samples ranged between 0 and 5ppm, which is lower than the WHO recommended value of 50mg/L (WHO, 2017). Second, the mean concentration of ammonia in the water samples ranged from 0 to 0.5. This falls precisely within the maximum limit of ammonia in drinking water which is 0.5mg/L (WHO, 2017). Third, the quantity of dissolved oxygen (0.9) was the least in Fiji water, thus indicating that it had the lowest rate of a chemical reaction. Moreover, there lacks no health-based guideline value recommended for dissolved oxygen (WHO, 2017). Fourth, the presence of iron and metal ions is justified by the fact that since Fiji water is obtained from an aquifer, the rock minerals had dissolved into the surrounding water. Lastly, the presence of bacteria in all water samples, especially E. coli, suggests that Fiji water is unsafe for human consumption. Some of the possible sources of error in the experiment include inaccuracies in the measurement of chemicals, calibration errors, sensitivity errors, and contamination.

What makes water safe is neither its color nor smell. The clarity and freshness of water do not matter if it is contaminated by micro-organisms such as E. coli that are invisible to the naked eye. Such micro-organisms are known to cause diseases that might even lead to death. Moreover, the water might contain harmful concentrations of metal ions and nutrients that can bio-accumulate and later result in health problems.

According to a study conducted by Keiser and Shapiro (2019), since the Clean Water Act was endorsed and passed in 1972, the federal government has invested $1 trillion to curb water pollution. However, presently, over half of the United States stream miles still violate the pollution standards. Therefore, this suggests that the Act has had a limited effect on the quality of water in rivers in the U.S.

Conclusion

The presence of minerals, nutrients, and micro-organisms such as ammonia (>0.1ppm), nitrates, chlorine, and E. coli suggests that Fiji water is contaminated with industrial effluents and sewage. As a result, Fiji water appears to be the most unfit for human consumption relative to the other three samples. Water quality is becoming an issue as the human population continues to grow and globalization increases. Globalization trends have significantly affected environmental policy issues such as the water sector. This is because the phenomenon has opened up countries and states to competition and other external influences, for instance, the increase in manufacturing and agricultural production processes. Pollutants produced as byproducts of pesticides, plastics, detergents, and synthetics, among others, pose a severe water quality risk and, consequentially, a human health hazard if poorly managed. Therefore, there is a serious need for issues affecting water quality to be addressed.

References

Fiji Water. (2017). Bottled water quality report. Web.

Keiser, D., & Shapiro, J. (2019).Consequences of the Clean Water Act and the demand for water quality. The Quarterly Journal of Economics, 134(1), 349396.

Khalifa, M., & Bidaisee, S. (2018). The importance of clean water. Journal of Scientific and Technical Research, 5(4), 1-4.

Khatri, N., & Tyagi, S. (2015). Influences of natural and anthropogenic factors on surface and groundwater quality in rural and urban areas. Frontiers in Life Science, 8(1), 23-39.

Pedersen-Shear, A., Bentley, M., Frances-Knight, S., Zeller, N., & Walters-Conte, K. (2019). BIO-100: Great experiments in biology, lab manual. Web.

World Health Organization (WHO). (2017). Guidelines for drinking water quality (4th ed.). Geneva: Switzerland, World Health Organization.

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