Effect Of UV Rays On Pool Chlorine Biology Essay

Effect Of UV Rays On Pool Chlorine Biology Essay Pools have always been a source of leisure for Australians. They provide enjoyment and good times for many households generated in a family or local swimming pool. Despite this, pools have to be maintained by using chemicals or disinfectants, lest unwanted pathogens create health hazards. However, the over use of these chemicals can also result in health hazards such as; serious irritation and breathing problems. A balance or equilibrium, therefore, must be achieved to maintain suitable conditions. This is where chemistry comes into play. The main type of chemicals used in pools to prevent unwanted pathogens is pool chlorine. Sodium hypochlorite is a commonly used as pool chlorine. It was discovered by Louis Pasteur in the late 19th century that sodium hypochlorite had disinfectant properties. Sodium hypochlorite effectively kills bacteria, viruses and fungi. When pool chlorine is added to water, a reaction takes place where hypochlorus acid is formed. In the past, most consumer chlorine bleach was sold in a 5.25% solution. Today, some more concentrated solutions are being sold and touted as an improvement over the less concentrated bleaches. To check for the concentration of the pool chlorine, excess potassium iodide is to be added to it and then it is to be titrated with a solution of sodium thiosulfate. The concentration of the liquid chlorine is then to be calculated using stoichiometry. The net ionic equations of the chemical reactions are: Source: Chemistry In use Book 2 There are also many factors that affect the effectiveness of pool chlorine such as sun radiation. Ultra-violet (UV) light degrades hypochlorous acid to hydrochloric acid (HCl). Ultraviolet (UV) radiation not only destroys light sensitive chemicals such as sodium hypochlorite (NaOCl), it also has the potential to significantly degrade the structural integrity of the storage tank or IBC containing the light sensitive material.   According to the NSW  Ministry of Health  (2010) roughly 1/3 of free chlorine exposed to UV lights in a outdoor swimming pool is destroyed every hour. UV light therefore lowers the concentration of the disinfection component of free chlorine. In this experiment, the concentration of sodium hypochlorite in pool chlorine, left under a UV lamps for different periods of times, was measured. Aim: To investigate the effects of Ultra Violet (UV) rays on sodium hypochlorite (a bleaching agent used commonly in pools). 2.0 Hypothesis: As pool chlorine is left for longer periods of time under UV rays, the concentration of the pool chlorine will decrease. This was hypothesised as the theory suggests that UV rays degrade the component in pool chlorine which allows it to disinfect bacteria. 3.0 Equipment/Material Material Diluted Sodium hypochlorite Sodium thiosulfate Potassium iodide Starch indicator Boiling water Equipment 2 x 100 mL Beaker 5 x 250 mL Beaker 15 x 100 mL Flask 2 x 1L Volumetric flask 1 x 500 mL Volumetric flask 1 x 100mL Measuring cylinder 2 x 20mL Measuring cylinder 3 x Funnel 5 x 20 mL Pipette 2 x 1mL Pipette 3 x Stirring rod Senior Balance Burette and stand UV Lamp Permanent marker Stopwatch 4.0 Safety To prevent any harm to the group during this experiment, safety precautions were taken to ensure the safety of the members. Refer to Appendix A for MSDS (Material Safety Data Sheet). Lots of glassware was used Refrain from holding too many pieces of glassware at once. Clean up glass immediately if any is broken. Handle boiling water with care Boiling water was used to create a solution of starch. Beaker tongs were used to carry the boiling water. Potassium iodide is irritating to eyes and skin Avoid contacting without gloves. Wash with water if contact occurs. Sodium thiosulfate is irritating to eyes and skin Avoid contacting without gloves. Wash with water if contact occurs. Starch gives skin discomfort Avoid contacting without gloves. 5.0 Procedure Refer to Appendix 1 for preparation of solutions Preparation of titration A burette and stand was filtered with the sodium thiosulfate solution. The burette was filled up with the sodium thiosulfate solution to around the 0mL mark. 100mL of diluted sodium hypochlorite was poured into 5 individual 250mL beakers. These beakers were labelled 0min, 15m, 30m, 1hr, 3hrs and 4hrs. All the beakers, except the 0min beaker, were placed under the UV lamp for the amounts of time labelled on them. At this point the stopwatch was started, once the samples had reach the specified time they were taken out. For each time sample, 20mL was measured with a pipette and placed into 3 100mL flasks. 10mL of potassium iodide solution and 2mL of starch indicator solution were prepared prior to every titration. Titration The mark of where the sodium thiosulfate solution in the burette was recorded before the titration occurred. 10mL of potassium iodide solution was added to each time sample of 20mL sodium hypochlorite solution in the 100mL flasks. The new solution was left until it has completed reacted (when the solution turns light yellow). The solution was then titrated until it turned a very pale yellow. 2mL of starch indicator solution was added to the titrating solution. This should make the solution a dark blue/black colour. Titration continued at a slower rate until the solution had turned clear. Record the finishing titre mark on the burette. These steps were repeated 3 times for each time sample (total of 18 titrations). Figure 1: Diagram of titration in progress. 6.0 Results Table 1: Table showing the amount of sodium thiosulfate solution added to sodium hypochlorite and potassium iodide solution at different times left under the UV ray. Refer to Appendix 2 for initial volume and final volume calculations and averages. Time (mins) Volume (mL) Average of 3 titrations 0 23.35 15 22.95 30 22.51 60 18.35 180 16.03 240 12.70 Table 2: Table showing the concentration of pool chlorine Refer to appendix 3 for converting of average volume of titration to concentration. Amount of time left under UV lamp (mins) Concentration of OCl (M) 0 0.03250 15 0.03198 30 0.03131 60 0.02558 180 0.02234 240 0.01770 Figure 1: Graph showing the concentrations of pool chlorine left under a UV lamp for different periods of time. 7.0 Discussion An experiment design was made to test and compare the effects of UV rays on pool environments, particularly on the impacts of chlorine concentration. In doing this, a total of 18 pool chlorine samples were put under a UV lamp for different periods of time. The concentrations of the chlorine when left untouched by UV rays were stable at around 0.03M. By exposing the pool chlorine samples to ultraviolet lights for given periods of time, the concentration of the chlorine decreased. The graph shows that as the sodium hypochlorite is more exposed to UV rays, the lower concentration of the pool chlorine was. A line of best fit was drawn to display the trend in the data. It showed that there is a linear relationship between the concentration and time left under a UV lamp. The data collected agrees with the theory that UV rays disrupt the structural integrity of the pool chlorine. The photodecomposition of chlorine is apparent as the initial levels of hypochlorite ion decreased by a signific ant amount when exposed to sunlight. The photochemical reaction that represents the situation of the experiment is: The main errors of the experiment were the inaccuracies of most aspects dealt with when implementing the experiment. One anomaly occurred when one sample of chlorine was left under the UV lamp for 60minutes. There is a major drop in concentration from 30min. This suggests that there was experimental error during the investigation. 8.0 Conclusion The results collected from this experiment suggest that the more pool chlorine is subject to UV lights, the lower the concentration of the chlorine will be. It has partially supported the hypothesis Bibliography Deb Smith, D. R. (2006). Chemistry in use Book 2. Sydney: Queensland Chemistry syllabus. Date retrieved: 05/09/12 Fletcher, D. J. (N/D). (The Sodium Hypochlorite Story). Retrieved September 5, 2012, from south shore gunite pools: http://www.southshoregunitepools.com/resources/htms/naocl.htm Gina A. Ishida, B. à ·. (N/D). IMPACT OF CHLORINE AND MONOCHLORAMINE ON ULTRAVIOLET. University of North Carolina, Chapel Hill, NC: N/A. Date retrieved: 05/09/12 N/A. (N/D, N/D N/D). Chlorination of pool water. Retrieved September 6, 2012, from pested: http://www.pested.msu.edu/resources/bulletins/pdf/2621/e2621chap7.pdf N/A. (1968). Stabiliser (Cyanurate) Use in Outdoor Swimming Pools. Retrieved September 5, 2012, from NSW Government Health: http://www.health.nsw.gov.au/utilities/copyright.asp Appendices Appendix A Going to add MSDS later†¦ Appendix 1 Diluting sodium hypochlorite 100mL of sodium hypochlorite was measured and put into a 1000mL volumetric flask. The flask was filled with distilled water up to the 1L mark The flask was inverted several times Sodium thiosulfate solution 8.82g of sodium thiosulfate was placed into a 1L volumetric flash The flask was filled with distilled water up to the 1L mark The flask was inverted several times Potassium iodide solution 5g of potassium iodide was weighed and placed into a 250mL beaker Distilled water was poured until it reached 105g on the scale The solution was thoroughly mixed Starch solution 1g of starch indicator was weighed and placed into a 250mL beaker 100mL of water was boiled and placed into the 250mL beaker The solution was thoroughly mixed and was left to cool down All solutions were labelled with the name of the solution, the concentration, a group members name and the teachers name. Appendix 2 Initial volume and final volume of sodium thiosulfate left under a UV lamp at different periods of time. 0 min 23.35-0.04 15 min 45.63-23.29 30min 22.34-0.07 = 23.31mL =22.34mL =22.27mL 46.76-23.31 23.04-0.14 44.78-22.32 = 23.45mL =22.90mL =22.46mL 23.54-0.13 46.66-23.04 23.01-0.21 =23.29mL =23.62mL =22.80mL Avg = = = =23.35mL =22.95mL =22.51mL 60 min 41.22-23.01 3 hour 15.62-1.23 4hours 13.23-0.12 =18.21mL =14.39mL =13.11mL 18.62-0.33 30.59-15.62 26.35-13.23 =18.29mL =14.97mL =13.12mL 37.26-18.72 49.32-30.59 38.21-26.35 =18.54mL =18.73mL =11.86mL Avg = = =18.35mL =16.03mL =12.70mL

Environmental Impacts of Airport Operations

Lutehr’s article focuses on the importance of understanding the environmental impacts of airport operations at both local and international level.According to Lutehr, only by having senior airport management develop such understanding would help in improving environmental quality and relations with airport neighborhood and stakeholders. Lutehr further argues that Airport management should ensure that various stakeholder groups are involved in matters pertaining to airport pollution and therefore agree on ways of pollution control.The most important stakeholder groups include airport neighborhoods that get affected by pollution and airlines whose activities lead to the pollution itself. Lutehr states water quality, noise, and air as the main forms of pollution emitted from airports and should therefore receive special and utmost attention.The author has improved his arguments through in depth research. For instance, he has borrowed heavily from EPA (Environmental Protection Age ncy) regulations concerning pollution. Luther has supported his arguments at two levels. The first one regards what should be done during the planning (construction and expansion) session and during the actual airport operation period.I completely agree with Lutehr’s arguments considering the impact of airport pollution. Most importantly, Lutehr has pointed the importance of brainstorming of possible pollution even before airports are constructed or expansion projects are undertaken. In other words, feasibility studies of pollution should be undertaken when airport construction and expansion plans are underway.This would ensure inclusion of pollution control plans in airport operations. As a stakeholder in airport pollution, I find myself well convinced by Lutehr’s arguments, especially considering the wide body of knowledge that supported his assertions. The author has indeed done a good job of convincing readers.ReferencesLutehr, L. (2007). Environmental Impacts of A irport Operations, Maintenance, and Expansion. Retrieved July 10, 2009, from http://www.fas.org/sgp/crs/misc/RL33949.pdf.Wayne, L. (2009). Airport Projects Delayed or Canceled. Retrieved July 10, 2009, from http://www.nytimes.com/2009/06/23/business/23airports.html?_r=4&src=twt&twt=nytimestravel&pagewanted=print

Many newspapers and magazines feature stories about the private lives

Many newspapers and magazines feature stories about the private lives of famous people. We know what they eat,where they buy their clothes and who they love. We also often see pictures of them in private situations. Is it appropriate for a magazine or newspaper to give this kind of private information about people? Give reasons for your answers. Everybody is interested to read the newspaper daily and also they used to read weekly or monthly magazine. Most of the people without fail used to read newspaper .People intention to read news paper to know about current affair and future development but the news paper and magazine are giving celebrities and famous person’ personal life instead of giving relevant news. In my opinion people hate this kind of inappropriate news. The news paper and magazine are publishing others personal life because of business. in fact people is not interested to know about others life. some people is interested to read about sports,science,business and politics.Moreover news paper and magazine should find relevant news for our society then only people like to read the news paper otherwise the ratio of buying newspaper will declined over period of time. The news reporter s are always seeing the news about celebrities personal life or their personal picture, which is not help our society, it may impact their business in their future. in addition the celebrities and famous people should not allow their personal life and should not discuss with media because it is not useful for people.Instead of going personal life,Reporters will collect the information like† How there are achieved their life and what is the secret of success† so this kind of things will help for our society. To sum up, The news paper and magazine should give good article, find out new information, which will help them to enhance the people knowledge and also the business will grow up. As far as my concern, may be people look at the news paper for others privacy but not interested to read anyone.

A Federal Policy Directive - 875 Words

After the initial DACA in 2012 there had not been any major immigration law changed or passed. DACA â€Å"a federal policy directive announced on June 15, 2012, has created new opportunities for about 1.9 million undocumented youth who came to the United States before the age of 16, have lived in the United States continuously fro at least five years, and have graduated from high school or obtained a GED† (ef4c.org, May 1, 2015). On February 16, 2015 Texas District Court Judge Andrew Hanen who put a ruling on a lawsuit supported by 26 states issued an injunction to delay the executive action set to be implemented on February, 18 2015. United We Dream is confident once the lawsuit reaches higher courts it will be turned down because it does not hold grounds. This action was much supported by the United We Dream not only because it further expanded DACA, which affects DREAMers, but it also positively impacts many parents, though not all. 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