Organic Chemistry - Lab Report Example

WATER CONTAMINATION: SOURCES, EFFECTS AND TREATMENT SCI 207: Dependence of Man on the Environment Water quality refers to the state of water in terms of its physical and chemical composition. Water is considered safe for consumption in its pure state. Water treatment seeks to restore the natural state of water by removing the impurities that are contained in water. This practical aimed at finding the effect of contaminants on ground water quality as well as the effectiveness of activated charcoal, alum and bleach in treating water. It also sought to compare the purity of bottled and tap water by determining their pH, chloride ion, phosphate ion, iron ion and ammonia concentrations using test strips. The three types of water assessed for purity in terms of their chemical compositions included Tap Water, Dasani® bottled and Fiji® bottled water. It was observed that bottled water contained more impurities than tap water, and that water treatment reduced the amount of impurities in the water. It was concluded that tap water was a safe and cheap source of drinking water. Outline I. Introduction II. Materials and methods III. Results IV. Discussion V. Conclusions VI. References Introduction Water quality is a term that illustrates the state of water. It encompasses the chemical, physical, biological and radiological attributes, usually with respect to its suitability for a particular purpose (Diersing, 2009). Water is considered contaminated if it contains certain substances to the extent that makes the water unsuitable for a given purpose (Ofwa, 2013). Contaminated water may have an unpleasant coloration, smell, taste, turbidity, organic matter, unsafe chemical substances, deadly heavy metals among other harmful substances (Fawell & Chipman, 2000). Contamination of surface waters, ground waters or seawaters creates a serious risk to life particularly when the water is used by humans for drinking and other domestic purposes. Most pathogens that cause illnesses such as dysentery, cholera and typhoid are most often found in contaminated water (Ofwa, 2013). There are many negative effects of water contamination with each type of contaminant having a different effect on human/animal health and ecology. The main objective of this lab practical was to examine the effect of contaminants on ground water quality, effectiveness of water treatment and purity of tap and bottled water. The first experiment sought to establish the effects of groundwater contamination while the second experiment looked at water treatment procedures and their effect on water safety. Conversely, the third experiment aimed at assessing the purity of three different types of drinking water (tap, Dasani® bottled and Fiji® bottled) in terms of chemical substances and minerals. It was hypothesized that the addition of impurities such as oil, vinegar and detergent would compromise the quality of water in terms of smell and color. It was also hypothesized that treating water would make it suitable for drinking. The final hypothesis was that Dasani® bottled water contained the least impurities while tap water contained most impurities. Materials and methods In the first experiment, eight clean beakers labeled 1-8 were used. Beakers labeled 5-8 were kept aside while 1-4 were filled with 100 mL of water using 100 mL graduated cylinder. The smell and colour of water in beaker 1 was recorded in Table 1. Onto 100 mL of water in beakers 2, 3 and 4, 10 mL of vegetable oil, 10 mL of vinegar and 10 mL of liquid laundry detergent were added and mixed thoroughly with a wooden stick. The observations made from these three beakers were then recorded in Table 1. The piece of cheesecloth was cut into five different pieces and folded to obtain a four layers thick piece big enough to line the funnel. The 100 mL beaker was used to measure 60 mL of soil, which was then placed into the cheesecloth-lined funnel. The funnel was then placed inside beaker 5, and the contents of beaker 1 poured through the funnel to filter into beaker 5 for a period of one minute. The observations of the filtrate in beaker 5 were recorded in Table 1. The cheesecloth and soil from the funnel were discarded. The above procedure was repeated for beakers 2, 3 and 4 with the contents of beaker 2 being filtered into beaker 6, those of beaker 3 into beaker 7 and those of beaker 4 being filtered into beaker 8. In experiment two, 100 mL of soil was added into 250 mL beaker, and the beaker filled to the 200 mL mark with water. The soil solution was then poured back and forth between two 250 mL beakers for a period of 15 minutes to make the water “contaminated.” 10 mL of the contaminated water was poured into a clean 100 mL beaker. This water sample was then compared to the “treated” water at the conclusion of the filtration procedure. Onto a 250 mL beaker containing the “contaminated” water, 10 grams of alum were added, and the mixture was stirred slowly with a wooden stick for 2 minutes. The solution was then allowed to sit for a period of 15 minutes. A folded piece of cheesecloth was lined in a funnel placed in a clean 250 mL beaker. A 100 mL beakers was used to measure 40 mL of sand, 20 mL of activated charcoal and 40 mL of gravel that were poured into the cheesecloth-lined funnel in that order. Clean tap water was slowly poured through the filter until the funnel was full in order to solidify the filter. Water used for rinsing the beaker was discarded, and the procedure repeated four more times. The funnel was returned to the top of the beaker and left to sit for 5 minutes before emptying the beaker. About three-quarters of the “contaminated” water was filtered into the beaker, and the smell of the filtrate was compared to that of the 10 mL soil solution prepared earlier. A few drops of bleach were added to the filtered water, and the mixture stirred slowly for 1 minute resulting into “treated” water. The “treated” water was then compared with the 10 ml sample of the initial “contaminated” water. In experiment three, three 250 mL beakers were labeled Tap Water, Dasani® and Fiji®. 100 mL of the each type of water was poured into the corresponding beakers. Ammonia test strips were used to test for the concentration of ammonia in the three water samples by comparing the color of the small pad to that of the color chart. The results were recorded in Table 2. A similar procedure was used to test the concentration of chlorine, phosphates and iron using chloride test strips phosphate test strips and iron test strips respectively. The 4 in 1 test strips were used to determine the pH, total alkalinity, total chlorine, and total hardness in the three water samples. Results The results of the three experiments are illustrated below in tables 1 to 6 below. Table 1: Water observations (smell, color, etc) Water Observations (Smell, C Beaker Observation 1 Typical tap water, clear, odorless 2 On the addition of oil, large bubbles bubbled up at the top and became smaller on stirring forming a layer at the top of water. 3 The water turned slightly cloudy on addition of vinegar with small bubbles forming. A loud smell of vinegar was noted. 4 The solution became quite cloudy looking like soapy water on addition of detergent into the water, and there were very tiny bubbles visible. 5 The water turned to a light-to-medium brown color with small particles of soil floating at the top of the water with a potting soil smell. 6 The water and oil mixture had a cleaner look to it although it was more of a light brown color. 7 The water and vinegar had a very light brown appearance, much cleaner than the other samples. 8 The water and detergent had a light-to medium-brown look, and it looked cloudy. Table 2: Ammonia Test Results Water sample Test results (mg/L) Tap water 0 Dasani® Bottled Water 0 Fiji® Bottled Water 0 Table 3: Chloride Test Results Water sample Test results (mg/L) Tap water 0 Dasani® Bottled Water 500 Fiji® Bottled Water 500 Table 4: 4 in 1 Test Results Water sample pH Total Alkalinity (mg/L) Total Chlorine (mg/L) Total Hardness (mg/L) Tap water 7 40 4.0 Dasani® Bottled Water 3 80 0.2 Fiji® Bottled Water 8 40 10.0 Table 5: Phosphate Test Results Water sample Test results (ppm) Tap water 25 Dasani® Bottled Water 10 Fiji® Bottled Water 100 Table 6: Iron Test Results Water sample Test results (ppm) Tap water 0.3 Dasani® Bottled Water 0 Fiji® Bottled Water 0.15 From Table 1, it could be observed that vegetable oil, vinegar, soil and detergent all contaminated water. Water treatment improved its physical appearance as could be seen from experiment two. Tap Water, Dasani® and Fiji® all contained 0 mg/mL of ammonia (Table 2), 0 mg/L, 500 mg/L and 500 mg /L of chlorine, respectively (Table 3). Out of the three water samples, Fiji® bottled water was slightly basic with a pH of 8 while Dasani® bottled water had a pH of 3 and tap water had a pH of 7 (Table 4). The phosphate concentration was highest in Fiji® bottled water (100 ppm) and least in Dasani® bottled water (10 ppm) (Table 5). Tap water was found to contain the highest iron concentration (0.3 ppm) while Dasani® bottled water contained 0 ppm of iron (Table 6). Discussion The results obtained from the above experiments confirmed the first and second hypotheses. However, the third hypothesis was denied. In the first experiment, oil, vinegar and laundry detergent contaminated water when added to it. Oil produced a film on top of water; vinegar yielded an overpowering smell and a light cloudy look while laundry detergent produced a medium cloudy appearance. In the second experiment, treating water improved its appearance hence making it safer than untreated water. The results of experiment three showed that even though bottled water was considered the cleanest with fewer impurities, tap water was shown to contain least impurities while Fiji water contained the most impurities. Underground water, which is the main source of fresh water is nonrenewable and has a replenishment period of centuries or more (Turk & Bensel, 2011). Therefore, it is vital to keep contaminants out of water since contaminated waters are potent agents of diseases such as cholera and typhoid, which affect humans (Ofwa, 2013). Some of the human activities that cause ground water contamination include, drilling for oil and natural gas, fracking, illegally dumping toxic and hazardous waste, improper handling of landfill sites. Although treated water looked potable, it was slightly cloudy and still appeared dirty, which could be attributed to inefficiencies in the treatment process, for example, inadequate time during the sedimentation process. The treatment process could be improved in future experiments by allowing sufficient time for dirt to settle at the bottom before filtration. The difference between the treated and contaminated water as per experiment two was that treated water looked clear while contaminated water appeared brown. Additionally, treated water was comparatively odorless while contaminated had the smell of potting soil. Conclusion The purpose of this experiment was to determine the effect of contaminants on water, effectiveness of treatment methods as well as the purity of Tap Water, Dasani® and Fiji® bottled water. The results showed tap water as the cleanest drinking water out of the three water samples while one of the most expensive bottled water on the market was littered with extras that humans do not need. Tap water is, therefore, healthier with fewer chemicals, safer to drink and significantly less costly than bottled water. References Diersing, N. (2009). Water Quality: Frequently Asked Questions. Key West, FL: Florida Brooks National Marine Sanctuary. Fawell, J., & Chipman, K. (2000). Endocrine disrupters, drinking water and public reassurance. Water Environ Manage, 5, 4–5. Kant, R. (2005). Remedial strategy- Drinking water pollution. Chemical Engineering World, 40(1), 95-100. Ofwa, F. D. (2013). Water pollution: Sources, effects, control and management. Mediterranean Journal of Social Sciences, 4(8), 65-68. Turk, J., & Bensel, T. (2011). Contemporary environmental issues. San Diego, CA: Bridgepoint Education. Read More