Based On River Pollution - Case Study Example

Case Study Based on River Pollution (Student Name) (Course No.) (Lecturer) (University) (Date) Introduction Environmental problems are commonly caused by anthropogenic activities that release toxins into the water bodies as well as the atmosphere, causing the loss of species and environmental hazards such as droughts and flooding. However, such environmental disasters occur when the capacity of the environment to absorb such pollutants is exceeded. Apart from observing the environmental problems that occur in any given area such as flooding, species extinction and drought, environmental analysis involves an investigation of the principal causes of such events and proposing recommendations to ensure that such events do not recur (Petrisier, 2014, p. 4, Morrison and Murphy, 2006, p. 7). The study explores the underlying causes of an environmental problem involving mass fish kills in River Styx approximately five miles from Styxton village. Fish kills refer to the death of fish species confined to a given area and usually linked with the death of other aquatic organisms. The causes of fish kills in an aquatic ecosystem are many and varied, with the most common one being oxygen depletion, specifically the reduced concentration of dissolved oxygen, which the fish depend on for survival (Govorushko, 2012, p. 60). Reduced concentration of dissolved oxygen in the water is caused by drought which causes an increase in the water temperature, algal blooms that compete with the aquatic organisms in the water for the dissolved oxygen as well as overpopulation in the aquatic environment (Goel, 2006, p. 3 and Jain, 2009, p. 76). The other causes of fish kills in a river include; diseases and parasites and toxicity to a lesser degree. The main reason why mass fish kills is considered as an environmental disaster is because the fish are keystone species and thus are indicators of environmental stresses. It is, therefore, important for the environmental agencies to determine the causes of fish kills as soon as they occur to enable them establish the causes of such kills and prevent their repeated occurrences. Generally, many fish species have very low tolerance to variations that occur in the aquatic ecosystems. The death of such species is an indicator of the possible environmental problems that adversely affect other species within the aquatic ecosystem as well as the other uses of the water such as drinking. Depending on the causes, fish kills can either be selective or general. Fish kills in the Styx River Fish kills in the Styx River can be linked with the presence of the Riverside Breweries, Styxton Sewage Plant and AB Chemicals at close proximity to the river thus releasing toxic waste, directly into the river contributing to the larger percentage of pollutant in the river. The manufacture of real ales by the Riverside Breweries involves a number of processes such as malting, milling, extract separation, hop addition and boiling, removal of hops and precipitates, cooling and aeration, fermentation, separation of yeast from young beer, aging, maturation and packaging. All these processes result in the release of brewery effluent which is channelled into the river. Brewery effluent also contains such phosphates resulting from the detergents used in cleaning. The high temperature brewing process also contribute to thermal pollution. The other possible source of river pollution resulting in the mass fish kills in the Styx River is the location of the Styxton Sewage plant near the river which releases sewage effluent into the river. The sewage treatment plant performs the treatment of the domestic wastes from the nearby village as well as the industrial wastes from the two industries. Although the chief engineer of the treatment plant denies the possibility of sewage leakages into the river, the state of the treatment plant, as well as the transportation of some of the wastes to the treatment plant via trucks, suggests that leakages may occur. Sewage effluent contains large amounts of suspended solids, harmful bacteria and nitrates that can alter the water quality hence resulting in fish kills. Also, the fish kills in river Styx could also result from the presence of the AB Chemical industry within the vicinity of the river that can cause mercury poisoning within the aquatic ecosystem. The two forms of mercury that pose threat to the environment are the liquid mercury and the vapour mercury. In an event where the concentration of mercury in the aquatic ecosystem is high, mercury can accumulate in the planktons that the fish feed on. Bio magnification can then occur within the food chain reaching very high levels high in the food chain, thus resulting in the death of the larger fish higher in the aquatic food chain. Although the management of the company denies the presence of leakages, mercury leakage into the river can have adverse effects on the fish populations in the river. Analysis Techniques To establish the cause of fish kills in the Styx River, different field and laboratory experiments were performed. The water samples from the river were collected using the sampling rod as part of the health and safety of the investigator. Sampling rods are made of polycarbonate with a large clamp on one side and are designed to steadily hold different sizes of sample containers. During water sample collection, the containers are placed on the cage to allow an efficient reach, while preventing the hand from contaminating the sample or contacting the wastes. To avoid the effect of the surface films on the collected sample, the container is lowered quickly but gently into the water Duncan et al, 2007, p. 16). The water temperature is also a significant factor in contributing to fish kills by reducing the amount of dissolved oxygen in the water. Therefore, the field experiment also involved measuring the water temperature using the thermometer. Soil samples were also collected in the area near the fish kills to help in determining the presence of any trace elements within the area that could have contributed to the massive fish kills that occurred in the river. To test for the presence of mercury within the Styx River, the Varian Model 65 Accessory was used. The technique consists of a reaction vessel, an in built magnetic stirrer to ensure quick reactions and a press button drain system that allows the efficient removal of the samples after analysis (Liu et al. 2012, p.52). It also contains a septum that allows the addition of reagents as well as a pellet dispenser that permits the use of sodium borohydride for hydride generation techniques. Determination of mercury using the cold vapour technique is achieved using a quartz absorption cell attached to a standard air acetylene burner. Samples are placed in the reaction vessel, followed by the addition of 1-2ml of 20% SnCl2 by weight in concentrated hydrochloric acid using a pipette. The vessel is then closed and then mixed by the in -built magnetic stirrer. The reaction takes place for two minutes before the inert gas is turned on sweeping the atomic mercury out of the reaction vessel into the quartz tube placed in the optical path of the atomic absorption instrument, producing a temporary atomic absorption peak (Shrader and Hobbins, 1983, p. 1-5). The other technique use in the analysis of the samples collected is the high performance liquid chromatography. The technique was used in determining the organic composition of the water (Li and Miglaccio, 2010, p. 157). Chromatography refers to the mass transfer process involving adsorption. The high performance liquid chromatography uses pumps to pass a liquid at very high pressure and a sample mixture through a column filled with a sorbent, causing the components of the sample mixture to separate. The sorbent, which is the active constituent of the column consists of granular material made of solid particles such as silica and other polymers ranging from 2-50 micrometres in size. The first thing to consider when using this analytical separation method is the retention time of a sample, which is the duration over which a sample is retained by the column in the stationary phase in relation to the time it resides in the mobile phase. The next step involves detecting how much of what is present. Here, the detector responds to the compound concentration as it passes through the flow cell, producing a stronger signal when the concentration is high. Soil samples collected near the site of the fish kills were also collected and analysed for the presence of trace elements such as arsenic. Soil samples were collected from the site using clean tea spoons and properly packed in a polythene bag and transferred to the laboratory for analysis. The soil sample was first dried in the laboratory before investigations for the presence of arsenic in the sample are done using the sorbed metal II plus method (Bhattacharya, 2007, p. 67). Findings Following the investigations conducted in the laboratory, significant amounts of methyl mercury were found in the samples of water collected from the Styx River. This suggested the presence of leakages within the chemical facility resulting in the release of methyl mercury into the water. Methyl mercury is a persistent pollutant and has the capacity to remain in the aquatic ecosystem for a long period of time (Lusk et al., 2005, p. 8-14). Additionally, methyl mercury is poisonous even in small amounts. Rainbow trouts are predators feeding on the eggs of other fish as well as planktons and range from 0.5 to 2.3 kilograms in the riverine environment. The presence of mercury in the water, therefore, suggests accumulation of the same by the planktons and the other small fish preyed on by the rainbow trouts. The fish mercury concentration also depend on the size of the fish and their tendency to accumulate methyl mercury in the food web (Bank, 2012, p. 221). Fish obtain methyl mercury from the food uptake that depends on their sizes and diet as well as the water quality factors that influence the methylation of mercury in the aquatic environment (Merkel, 2011, p. 1-2). Thus, the rainbow trout in river Styx must have obtained methyl mercury from feeding on other smaller fish and their eggs. Since biomagnification occurs higher in the food chain, acute toxic effects and death occurs in the larger fish species such as the rainbow trout. The water temperature is also another factor that caused the death of the rainbow trout in river Styx. Before the occurrence of the mass fish kills in the river, there was no rainfall during that week and the diurnal temperatures recorded during the week were as high as 820F. Measurements of the water temperature using the thermometer also further proved the high temperatures of the lake. The survival of organisms in the aquatic environment depends on the environmental temperature (Lushack, 2011, p. 5). An increase in the water temperature reduces the amount of dissolved oxygen, on which the fish depend on. This increases the competition between the aquatic organisms for dissolved oxygen, wiping out populations that cannot survive under low oxygen concentrations. An increase in temperature also increases the rate of metabolism in the aquatic organisms, thus increasing the uptake of oxygen from the water. This leads to the reduction in the concentration of dissolved oxygen in the water hence causing increased competition within the aquatic environment, eventually leading to fish kills. From the chromatography analysis performed, it was established that the water also contained significant amounts of organic wastes that could also lead to the fish kills seen in the river. The presence of organic wastes in the water is as a result of the leakage of the sewage waters into the water. A thorough scrutiny of the sewage water treatment plant also established channels of leakages from the old pipes that require modernization. The presence of nitrates in the sewage waters are linked to the increased algal blooms within this area of the river, which reduce the concentration of dissolved oxygen in the water hence the massive fish kills. Moreover, the release of bacteria into the water by the brewing industry is a significant contributor of organic wastes that can cause mass fish kills. However, the concentration of organic wastes in the river was not too high to cause fish kills. Sewage wastes also contain arsenic. The transportation of wastes by trucks from the breweries and the chemical plant can cause soil contamination if some of the wastes drop from the trucks. The laboratory analysis of the soil also indicated the presence of arsenic in the soil. In the event of rainfall, runoff carries the soil together with the arsenic into the water causing pollution of the river. Arsenic is also a trace metal and is dangerous even in small amounts. The uptake of arsenic by fish is from feeding and can have detrimental effects on the fish when the concentration exceeds a given limit (Murphy and Morrisson, 2007, p. 279, Naidu, 2006, p. 34, Ravenscroft et al., 2011, p. 49). However, the arsenic levels in the soil did not cause the fish kills in the river. From the above discussion, it is evident that the fish kills in river Styx were caused by the mercury poisoning resulting from the methyl mercury production industry situated near the river. The investigation revealed the presence of leakages in the industry that channels wastes into the river. To avoid such occurrences in the future, /it is recommended that the methyl mercury plant be maintained in a good condition to avoid leakages of mercury into the water. Wastewater from the plant should also be efficiently treated to avoid the releasing the heavy metals from the plant into the river (Keenan et al., 2011, p. 24-56). The companies and industries contributing to the pollution of the river should be made to incur the cost of environmental clean ups or be sued legally (Singh, 2007, p. 22). Also, the environment protection agency should conduct regular check- ups of the river to establish the water quality parameters to help in understanding the health of the ecosystem. References Bank, M. S. (2012). Mercury in the Environment Pattern and Process. Berkeley, University of California Press, p. 221. Bhattacharya, P. (2007). Arsenic in soil and groundwater environment biogeochemical interactions, health effects and remediation. Amsterdam, Elsevier, p. 67. Duncan D, Harvey F, Walker, M and Australian Water Quality Centre. (2007). EPA Guidelines: Regulatory monitoring and testing: Water and wastewater sampling, p. 16. Govorushko, S. M. (2012). Natural processes and human impacts interactions between humanity and the environment. Dordrecht, Springer, p. 60. Goel, P. K. (2006). Water pollution: causes, effects and control. New Delhi, New Age International, p. 3. Jain, A. K. (2009). River pollution: regeneration and cleaning. New Delhi, A.P.H. Pub. Corp, p. 76. Keenan, H., Horvat, M., Kocman, D., Ogrinc, N., & Žagar, D. (2011). Mercury in the aquatic environment: sources, releases, transport and monitoring. Geneva, GESAMP, p. 24-56. Li, Y & Migliaccio, K. (2010). Water Quality Sampling, Concepts and Analyses, p. 157. Liu, G., Cai, Y., & O'Driscoll, N. J. (2012). Environmental chemistry and toxicology of mercury. Hoboken, N.J., Wiley, p. 52. Lusk, J. D, Rich, E and Bristol, R. S. (2005). Methyl mercury and other Environmental Contaminants in Water and Fish Collected from Four Recreational Fishing Lakes on the Navajo nation, 2004, p. 8-14. Lushchak, V. I. (2011). Environmentally induced oxidative stress in aquatic animals, P. 1-18. Merkel, C. (2011).Methyl Mercury. Microbac Laboratory Services, p. 1-2. Morrison, R. D., & Murphy, B. (2006). Environmental forensics contaminant specific guide. Amsterdam, Elsevier Academic Press, p. 1-10. Murphy, B., & Morrison, R. D. (2007). Introduction to environmental forensics. Amsterdam, Elsevier/Academic, p. 279. Naidu, R. (2006). Managing arsenic in the environment from soil to human health. Collingwood, VIC, CSIRO, p. 34. Petrisier, L. G. (2014). Environmental Forensics Fundamentals: A Practical Guide, p. 4. Ravenscroft, P., Brammer, H., & Richards, K. (2011). Arsenic Pollution A Global Synthesis. New York, NY, John Wiley & Sons, p. 49. Shrader, D & Hobbins, W. (1983). The Determination of Mercury by Cold Vapor Atomic Absorption. Varian AA Resource Centre, Illinois, U.S.A, p. 1-5. Singh, L. B. (2007). River Pollution. New Delhi, A.P.H. Publishing Corporation, p. 22. Read More