Thursday, June 10, 2010

When it comes to water pollution there are four categories that all pollutants come from. They can either be biological pollutants, chemical pollutants, physical pollutants, or thermal pollutants. All of these affect the water in different ways but in the end they are all harmful to both the environment they are introduced to and the humans who come into contact with the water.
Three pollutants that reduce the quality of water consist of high temperature discharges, microorganisms, and nutrients. High temperature discharges degrade water quality by any process that changes ambient water temperature and is a non point source. Microorganisms consist of bacteria, viruses, and Giardia and are also a non point source. Nutrients are nitrogen and phosphorous and are a non point source. To detect High-Temperature Discharges scientists take the temperature of a
body of water a compare it to records. If it is detected possible sources are evaluated and measures are taken to stop or reduce it. Many generators and large engines can cause High-temp discharges that can affect water life in small areas. Many forms of sea life can be affected by HTDs. Coral is an example of the damage HTDs can cause because when the water near coral is heated the reef process is slowed down and usually the coral becomes bleached. Scientists detect microorganisms by taking samples of a water source and examining it under a microscope. Many microorganisms are parasitic and can enter any animal that drinks or swims in the water. Once infected an animal can become emaciated and can even die. A good example of this is Mexico. There is a high concentration of harmful bacteria in some Mexican water sources that can cause moderate to severe infections. Many fertilizers used on lawns can leech into the soil or directly drain into storm drains and end up in a body of water. This excess of nitrogen from the fertilizer can cause a rapid, widespread growth of algae which can disrupt the ecosystem. The extra oxygen used by the algae can literally choke fish and other aquatic life to death. This in turn can affect coastal regions dependent on fishing.
Water pollution prevention requires a heightened level of consciousness, including what type of vehicle and how far or often the vehicle is driven. Driving less is part of a quality water pollution prevention program as the vehicles on the road are responsible for at least 1/3 of the nitrogen pollution in the Earth’s water. When pollutants such as nitrogen enter the water it becomes stagnant or is overloaded with waste. The water is then unable to handle the biological material, and it soon becomes polluted. A critical factor operating under such a situation is the biological oxygen demand (BOD). It refers to the oxygen requirement by the metabolizing organisms. As the number of organisms increases, the demand for oxygen increases proportionally. Depletion of oxygen in water may lead to death of fish and other aquatic animals, a flat taste of water, and eventual death of aerobes. The best way to prevent water pollution is for you yourself to do it. Some ways to prevent water pollution are replacing shower heads and faucet aerators with water efficient models, using a water-filled milk jug or plastic bottle in your toilet tank to displace water; this allows your toilet to operate using less water, or you can buy no phosphate or low phosphate detergents. Due to the fact that many detergents have high phosphate levels when they enter a stream or lake they elevate the natural levels which can kill fish and other wildlife. You can also use a broom instead of water to clean your driveway or garage but do not sweep debris into the street or storm sewer or you can put a spray nozzle on the end of your hose for car washing and plant watering to prevent the hose from continually releasing water and to control the amount of water used.
Biological water pollutants are when carbohydrates are converted to carbon dioxide and water, which are also useful to plants. The plants then release °2 through photosynthesis. Due to rapid movement of water, aeration is more or less constant and the wastes eliminated. However, th
ere arises the problem, when water becomes stagnant or is overloaded with waste the water is then unable to handle the biological material and it soon becomes polluted. We have already seen how a lake may turn into a swamp due to overabundance of organic matter. Considerable evidence has shown that environmental contaminants such as polychlorinated biphenyls (PCBs) contribute to marine mammal mortalities by affecting their immune systems. Marine mammals are at particularly high risk of immunotoxicity because of their high trophic levels, long life span, and limited capacity to eliminate PCBs. PCBs and biological pollution may have lethal consequences for seals living near urban areas that receive high levels of bacterial pathogens, which are areas characterized by elevated fecal coli form counts.
Chemical water pollutants are metals or solvents from industrial work, pesticides from farming, or petroleum from oil spills. These pollutants often become diluted but even the
y are still able to radically alter the ecosystems they enter and allow the overproduction of certain forms of algae and bacteria that pollute the water with respect to its use by humans. Once in the water, the growth of microorganisms can be exacerbated by environmental factors such as the water temperature and the chemical composition of the water. For example, runoff of fertilizers from suburban properties can infuse watercourses with nitrogen, potassium, and phosphorus. All these are desirable nutrients for bacterial growth. Too much of a plant nutrient may lead to excessive plant growth, while synthetic organic compounds may cause physiological changes in aquatic organisms, or may become lethal at high concentrations. Pollutants can be taken up by plants and animals through contact with contaminated sediments, or directly from the water. Plants and organisms that become contaminated from these sources can pass the contamination up the food chain as predators consume them
Physical water pollutants and thermal water pollutants both increase things already found in the water such as dirt and sediment or heat, except these are polluted. Physical pollutants cause the water to become cloudy due to presence of some particulate matter such as sand or soil. These turn the consistency of the water to that of pea soup. The presence of some phosphates or nitrates may encourage the growth of algal blooms leading finally to a condition known as eutrophication. This upsets the ecological balance. Thermal water pollutants, also known as thermal discharge, introduce waste heat into bodies of water that support aquatic life. The addition of heat reduces the water's ability to hold dissolved gases, including the oxygen required for aquatic life. If the water temperature is greater than 95 degrees Fahrenheit, the dissolved oxygen content may be too low to support some species. If the differential temperature is too large, the difference can also stress some species. As a result, thermal pollution can wreak havoc on native fish species, such as trout, that require cold water with high levels of dissolved oxygen. When the water becomes warmer, other non-native fish that thrive in the warmth can take over habitats from native fish. In addition, warmer water allows bacterial populations to increase and thrive, and algae "blooms" may occur.
There are four levels of biochemical health risks biohazard 1, 2, 3, and 4. Biohazard one is bacteria and viruses including bacillus subtilis, canine hepatitis, escherichia coli, varicella (chicken pox). Usually contaminated materials are left in the open (but separately indicated) waste receptacles. Biohazard two is bacteria and viruses that cause only mild disease to humans, or are difficult to contract via aerosol in a lab setting, such as hepatitis A, B, and C, influenza A, Lyme disease, salmonella, mumps, measles, scrapie, dengue fever, and HIV. Biohazard three is Bacteria and viruses that can cause severe to fatal disease in humans, but for which vaccines or other treatments exist, such as anthrax, West Nile virus, Venezuelan equine encephalitis, SARS virus, variola virus (smallpox), tuberculosis, typhus, Rift Valley fever, Rocky Mountain spotted fever, yellow fever, and malaria. Biohazard four viruses and bacteria cause severe to fatal disease in humans, and for which vaccines or other treatments are not available, such as Bolivian and Argentine hemorrhagic fevers, H5N1(bird flu), Dengue hemorrhagic fever, Marburg virus, Ebola virus, hantaviruses, Lassa fever, Crimean-Congo hemorrhagic fever, and other hemorrhagic diseases.
Preventive measures of biochemical health risks contain the four biohazards. Biohazard one decontamination procedures for this level are similar in most respects to modern precautions against everyday viruses (i.e.: washing one's hands with anti-bacterial soap, washing all exposed surfaces of the lab with disinfectants, etc); decontamination can be achieved by treating with chemical disinfectants or by steam autoclaving. Lab coats are required and gloves recommended. The laboratory work is supervised by an individual with general training in microbiology or a related science. Biohazard two is research work (including co-cultivation, virus replication studies, or manipulations involving concentrated virus) can be done in a BSL-2 facility, using BSL-3 practices and procedures; biological safety cabinets (Class 2, type A, BSC) must be available. An autoclave should be readily available for decontaminating waste materials. Lab coats, gloves and face protection are required. The laboratory work must be supervised by a competent scientist who understands the risk associated with working with the agents involved. Biohazard three is when containment is required for infectious agents that may cause serious or potentially lethal diseases as a result of exposure by inhalation. The laboratory must be a separate building or isolated zone, with double-door entry, directional inward airflow. Lastly, biohazard four, the entrance and exit of a level four biolab will contain multiple showers, a vacuum room, an ultraviolet light room, autonomous detection system, and other safety precautions designed to destroy all traces of the biohazard.
Diseases of chemical health risks cause significant additional
effects to the nervous system and immune system after prolonged exposure. Illnesses identified by medical researchers include adult and child cancers, numerous neurological disorders, immune system weakening, autoimmune disorders, asthma, allergies, infertility, miscarriage, and child behavior disorders including learning disabilities, mental retardation, hyperactivity and ADD (attention deficit disorders). Common pesticides used in homes and lawns are now being shown in medical research to accelerate aging of the immune and nervous system resulting in serious health problems years after exposure. Of significant concern are agriculture and consumer use of pesticides however they are not currently required to be tested for subtle neurological effects (i.e. memory, depression, behavior), child learning disorders, or pregnancy developmental studies and immune system effects (i.e. lower white blood counts, increased infection rates and autoimmunity).
Preventive measures of chemicals heath risks are to use lead-free gasoline, which allows the use of catalytic converters on vehicles' exhaust systems; drive more fuel-efficient vehicles, such as hybrid gas-electric vehicles; change power plants and industrial plants that burn fossil fuels; and use a variety of filtering methods to reduce particles and scrubbing methods to reduce gases. The ideal method to abate or diffuse the chemical pollution of waterways is to minimize or avoid the use of chemicals for industrial, agricultural, and domestic purposes. Adapting practices such as organic farming and integrated pest management could help protect waterways. Lastly, by properly treating hazardous waste and by recycling chemical containers and discarded products containing chemicals this reduces solid waste buildup and leaching of toxic chemicals into waterways
Diseases of physical health risks are cancer, including prostate cancer and non-Hodgkin’s lymphoma, hormonal problems that can disrupt reproductive and developmental processes, damage to the nervous system, liver and kidney damage, and lastly damage to the DNA. To prevent these diseases, water pollution control methods can be subdivided into physical, chemical, and biological treatment systems. Most treatment systems use combinations of any of these three technologies. Additionally, water conservation is a beneficial means to reduce the volume of wastewater generated.
Lastly, diseases of thermal health risks are respiratory disease, cardiovascular disease, throat inflammation, chest pain, and congestion. Preventive methods for thermal health risks are cooling ponds, man-made bodies of water designed for cooling by evaporation, convection, and radiation, cooling towers which transfer waste heat to the atmosphere through evaporation and/or heat transfer, and also co-generation which is a process where waste heat is recycled for domestic and/or industrial heating purposes. By learning what pollutes the water and how these pollutants can affect an environment or a human body people are better able to stop the pollution or at least reduce it.
The environmental factors that each type of pollution affects is oftentimes devastating. Chemical water pollution arises from the use of pesticides by farmers. The pesticides get into the water through run off, when it rains and the pollutants are transported into bodies of water. This run off pollutes the water poisoning the aquatic life, and anything that consumes it. This may affect humans who consume fish from a contaminated body of water, or if the human consumes an organism that had consumed a poisoned fish. Thermal pollution affects an environment by destroying the base of a food chain. Since aquatic life has adapted to a small range of temperatures, the slightest change can make a body of water inhabitable for the organism. This causes the predator of that organism to starve because of lack of food. This would continues until the entire food chain is destroyed. Biological pollution has the same type of effect, only it starts the reaction by sickening the aquatic life through various biological agents. These agents are introduced through wildlife around the water through such means as feces. One such way is a parasite that causes Bever Fever in humans. The parasite is found in contaminated water and will cause cysts in the host. Physical pollutants, also, destroy the aquatic food chain of a body of water. The sediment clouds the water slowing photosynthesis eventually killing off the absolute base of a food chain, the plants. Without plants no ecosystem can survive.

Sunday, June 6, 2010

Sources of Pollution

Water pollution can come from a multitude of sources; these tend to fall into the categories of agricultural waste, domestic waste, and industrial waste. All three types of waste have different effects on the environment and on humans. In order to protect ones self these effects need to be known so humans can take the necessary precautions in order to protect themselves.

The three main sources of water pollution consist of industry, agriculture, and human waste. In the United States, “industry accounts for more than half the volume of all water pollution and for the most deadly pollutants”. Industry contaminates water through the waste and byproducts it creates. Pollutants such as heavy metals, phosphates, and sulfates can be attributed to industrial factories. These factories use fresh water to carry waste away into streams, lakes, oceans, and other bodies of water; furthering the dispersion of the waste. Since industrial waste is directly injected into the bodies of water, it is considered a point source pollutant. Agriculture pollutes the water with the use of fertilizers, pesticides, and other chemicals through run off. The chemicals used by farmers will often stay in the soil and on the land for many years, and when it rains the chemicals are swept away by the rain and drained into fresh bodies of water. Because there are many sources of pollution from agricultural, it is deemed as a non-point source pollutant. Municipal waste is a large contributor to water pollution as well. Human waste pollution comes after the filtration and cleansing of sewage, after this process the excess sludge and chemicals are dumped, they then seep into the top soil and eventually find their way into a well or other bodies of water. As the population consistently grows, the municipal waste increases exponentially. This is a non point source pollutant since the pollution occurs when the sludge from the waste filtration is placed in the earth not directly into the water.

Water pollution from agricultural waste, like industrial farms, results from storage and disposal of animal waste. Industrial farms store their animal waste and other farm wastes in huge tanks called lagoons, but these tanks can often leak, which causes environmental damage that can be 160 times as damaging as raw sewage. Fertilizers are also used in industrial farms and causes agricultural waste. Phosphorous and nitrogen are minerals that fertilizers contain, too much of this can cause algal bloom, which is when there is a rapid increase of algae in an environment, which kills fish. Livestock manure is used in these industrial farms and contains high concentrations of ammonia. Dissolved ammonia is highly toxic to fish and can also be converted to dangerous nitrates. Elevated nitrate levels in drinking water are highly toxic to humans. Lastly antibiotics and artificial growth hormones are also used in industrial farms. Large amounts of both substances end up being excreted by animals and can thus pollute water along with everything else in livestock waste. Some hormones can remain functional in manure up to 270 days after excretion, and there have been many documented cases of hormones discovered miles downstream of farms.

Industrial waste is due to the runoff sewage released into water supplies from factories, mining sights, or other industrial areas. This type of waste contains numerous pollutants. Some examples of industrial waste water pollution are lead, mercury, nitrates, phosphates, sulfur, oils, and petro chemicals. Lead and mercury are metallic elements that can cause health and environmental problems as well. They are non-biodegradable substances so it is hard to clean them up once they contaminate an environment. Lead can inhibit the action of bodily enzymes while mercury can cause illness through mercury poisoning. The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, an abundant accumulation of nutrients that support a dense growth of algae and other organisms, the decay of which depletes the shallow waters of oxygen in summer. Sulfur is a non-metallic substance that is also harmful for marine life. Another contaminate is oil which does not dissolve in water; instead it forms a thick layer on the waters surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds because they swim or fly into the oil and become coated in it. Oil can clog the gills of a fish and prevent birds from flying. Lastly petrochemicals are formed from gas or petrol and can also be toxic to marine life.

The City of Tianjin is China’s third largest industrial city and for years it has caused many environmental problems due to the fact that the construction of urban drainage, sewage, and wastewater treatment are far behind the environmental requirements for the city. This has caused the farmers to use untreated wastewater for drinking and agricultural purposes. Also, the industrial plants located in the City of Tianjin have managed to contaminate one of China’s five largest freshwater lakes, Chao Lake. This lake is used to supply water to the surrounding provinces but with the large industrial waste polluting it less and less water can be used from the lake. Recently a wastewater improvement project has been proposed and co-financed by the Tianjin Municipal Government and the World Bank to improve the city’s water. This project will focus on the improvement of waste managements systems.

The various substances that we use for keeping our houses clean add to water pollution because they contain harmful chemicals. Most detergents and washing powders contain phosphates which are used to soften the water, among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water. When sewage enters a lake or stream, microorganisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. Sewage-contaminated water causes eutrophication, which is the increase in concentration of chemical elements required for life. The nitrates, phosphates, and organic matter found in human waste serve as a food for algae and bacteria. This causes these organisms to overpopulate to the point where they use up most of the dissolved oxygen that is naturally found in water, making it difficult for other organisms in their aquatic environment to live. The bacteria are basically strangling the other organisms. Some of the organisms that do overpopulate from this are also disease-causing microorganisms; these diseases are then spread to humans when they drink said water. Phosphates are also found in soaps and detergents, but there are other household products that we use every day that can be toxic to many animals and humans if they are dumped directly into a body of water. All of these harm both the environments they are introduced to and the humans who drink the water.

There are several ways to detect water pollution sources but one of the most common ways is to use a detecting tube for nitrite; nitrate monitoring was developed as a spot test. The detecting tube is prepared by the packing of poly(vinyl chloride) (PVC) particles coated with a quaternary ammonium salt into a mini-column. A nitrite solution is then treated with sulfanilic acid and 1-naphthol; the resultant colored solution is then drawn into the detecting tube by suction with a syringe, and a color band is formed in the tube. The color band length (CBL) corresponds to the nitrite concentration. Nitrate is also detected after reduction with zinc. The nitrite and nitrate content of domestic wastewater samples is successfully detected by this method over the range of 0.5–45.3 mg-N L−1 as nitrogen concentration. Another type of detecting tube is prepared by alternately packing adsorbent and uncoated PVC particles in a mini-column. Colored zebra-bands are formed in this column, and the nitrite concentration is detected by counting the number of colored zebra-bands. Nitrite and nitrate concentrations in actual wastewater samples are detected more easily by this method, although the accuracy is somewhat lower than that obtained with the CBL method.

A chemical sensor array is used to continuously monitor for the presence or absence of industrial pollutants in the headspace of wastewater generated from an on-line flow-cell. A domestic wastewater is doused with diesel to stimulate the presence of an intermittent discharge in a wastewater influent. Response patterns between the sensors are used to detect for the presence of organic compounds in the wastewater. Correlations between the sensor response patterns or fingerprints are also analyzed using principal component analysis. The results clearly demonstrate that a chemical sensor array can rapidly identify the presence of organic compounds (such as diesel) in a wastewater matrix and could be further developed to monitor for industrial pollutants at the inlet of sewage works.

Friday, June 4, 2010

Classifications of Water Pollution



Water pollution can cause harm to the surrounding environment and its inhabitants. Protecting the environment should be a prevalent issue for all people, since there is no way to get around using water. There are two classifications of water pollution sources, point and non-point source pollution. By identifying how the water is being polluted it makes it easier to fix the problem.
There are many causes of water pollution; these include sewage, nutrients, waste water, chemical waste, radioactive waste, oil pollution, plastics, alien species, and other forms. This pollution affects everything. Through oil spills aquatic life is disrupted and many animals are killed. Sewage also carries harmful substances within it which then contaminates the water and the fish living in it. Point source pollution comes from one specific source, it can come from wastewater discharge, power plants, and industrial plants; a good example is the Exxon Valdez oil spill. A more recent example of point source pollution is the BP oil spill that is taking place now, where crude oil is spewing directly into the Gulf of Mexico. Non-point source pollution is caused indirectly through environmental sources. It can come from storm water from large land areas; this is mostly seen in streams and lakes. An example of this is when fertilizer used for farming purposed is washed into a stream due to rain.
There are a number of ways to detect water pollution. These ways can range from the simple method of merely smelling the water and visually analyzing it, to using some of the most advance technologies in the world today. The smell of rotten eggs, which is actually hydrogen sulfide gas in the atmosphere and produced by many pathogenic bacteria, can warn population of water pollution. To discover the extent of the pollution, technology plays a very prominent role. Water pollution can be detected in laboratories, where samples of water are analyzed for different contaminants. Living organisms such as fish can also be used for the detection of water pollution through their changes in behavior and growth. By detecting the problem of water pollution early on, it becomes easier to stop later on.
Many diseases due to water pollution come unnoticed; some diseases that water pollution can cause are cancer, kidney damage, organ failure, and nervous damage. There are many ways to prevent water pollution which then lessen the likelihood of developing one of the diseases that are associated with water pollution. Some ways to prevent water pollution and the diseases are to dispose of toxic products and trash properly, refrain from throwing liter into streams and lakes, use environmental friendly products, and also use natural fertilizers.

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