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Advantages of evaporation
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Introduction
“Pervaporation is a process in which a liquid stream containing two or more components is placed in contact with one side of a nonporous polymeric membrane, while a vacuum or gas purge is applied to the other side. The components in the liquid stream sorb into the membrane, permeate through the membrane, and evaporate into the vapor phase” (Freeman 6.59). The term pervaporation is derived “from the two major operations, involved in the separation process, namely, permeation and evaporation” (Peng Ming 815-820). Pervaporation has become more common place in the recent years regarding environmental concerns; this is mostly due to its effectiveness in removing volatile organic compounds from large amounts of water. Conventionally, air stripping or activated carbon are used in these situations but pervaporation has certain advantages over these methods. “Air stripping is susceptible to fouling and merely turns a water pollution problem into an air pollution problem, and activated carbon treatment involves costly regeneration steps and may not be suitable for VOCs that are easily displaced by other organic compounds” (Freeman 6.59). There are also a number of other advantages to pervaporation. The process creates no fugitive emissions, so there is no air pollution created. On the permeate side of the membrane, volatile organic compounds are continuously removed, so there are no regeneration costs. Also, the process uses compact systems and there is potential to recycle or reuse the recovered volatile organic compounds. The theory behind pervaporation can be explained through mathematical equations and certain experimental parameters.
Theory
Membrane performance is evaluated by the experimental parameters of permea...
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...en used to meet NPDES limitations.
There are few limitations on the use of pervaporation technology. First, the pre-filter needs to be cleaned frequently to prevent solids from clogging it. Second, anti-scalents need to be added with influent streams of high alkalinity. Lastly, “highly soluble organics, such as alcohols, are not effectively removed by a single-stage pervaporation process” (Zenon Environmental, Inc. 4). Even with some limitations pervaporation has been proven to be an effective technology.
Pervaporation removes volatile organic compounds to near maximum contaminant levels. Pervaporation modules produce satisfactory results with minimal personnel in a compact design. With spiral-wound, hollow-fiber and plate and frame style modules there is a good amount of flexibility in the technology for treating various pollutants at various concentrations.
The peristaltic pumps are widely used in chemical , dispensing, cosmetic, food processing and water treatment field.
What is a pesticide?A pesticide is a chemical substance used to kill pests, especially insects. A pesticide is also refered to as a biocide. Most pesticides are applied in spray form but occasionaly you will see pesticides that are in powder or pellet form. Pesticides are used on a variety of things, anything from crops like corn, barley, and wheat, to plants like petunias, marigolds, and rhodadendrons, which are usually found in small gardens greenhouses, and even in your backyard.
Disinfection is applied in water as well as wastewater treatment as a finishing step so as to destroy pathogens but the cause of concern regarding the disinfection process is the formation of disinfection byproducts (DBPs). Natural organic matter (NOM) in water has been considered as the predominant DBP precursors. Disinfectants are powerful oxidants that oxidize the organic matter present in water forming DBPs. Chlorine, ozone, chlorine dioxide, and chloramines are the most common disinfectants used nowadays and each produces its own suite of chemical DBPs in finished drinking water (Richardson, 2003). DBPs so formed pose a threat to human health because of their potential to cause cancer and reproductive/developmental effects. Most developed nations have regulated concentration of DBPs so as to minimize exposure to potentially harmful DBPs while maintaining adequate disinfection and control of targeted
The hypothesis for this experiment was, If three different types of waters (saltwater, fresh water, tap water) are tested, then the liquids won’t evaporate at the same rate and tap water will evaporate at the fastest rate because it won’t have any non-volatile substances to hold it back from evaporating.
Comment on class result with respect to differences in filter types, differences in filter assemblies, and overall on the confidence you would have in using this type of sterilisation process in preparation of pharmaceutical products. List the factors that may cause contamination during filtration. (20 marks)
...ion, Proceedings of the 5th Annual International Conference on Remediation of Chlorinated and Recalcitrant Compounds, (2006) Monterey, CA, May 22-25.
In this paper over natural refrigerant I will be covering the pros and cons of natural refrigerant in light commercial and residential applications. There are many natural substances in this world that can be used to help or decrease the efficiency of a heating ventilation air conditioning system. Some of these substances are water, air, ammonia, and hydrocarbons. All these substances are natural that come from the earth we live on. Over the course of this paper I will be covering the pros and cons of swamp coolers, geo thermal heating and cooling units and how these natural substances can help and or decrease how your heating and cooling unit performs.
The sample was subjected to steam distillation as illustrated in Figure 1. A total of 50ml of distillate was collected while recording the temperature for every 5.0 ml of distillate. The distillate was transferred into a 250ml Erlenmeyer flask and 3.0 g of NaCl was added. The flask was cooled and the content was transferred into a 250-ml separatory funnel. Then 25.0ml of hexane was added and the mixture was shaken for 5 minutes with occasional venting. The aqueous layer was discarded and the organic layer was left inside. About 25.0ml of 10% NaOH was then added and the mixture was shaken as before. The aqueous layer was collected and then cooled in an ice bath. It was then acidified with enough 6.00 M HCl while the pH is being monitored with red litmus paper. Another 25.0 ml of hexane was added and the mixture was shaken as before. The hexane extract was saved and a small amount of anhydrous sodium sulfate was added. The mixture was then swirled for a couple of minutes then filtered. A small amount of the final extracted was tested separately with 1% FeCl3 and Bayer’s reagent.
These items are removed by a bar screen that the waste water flows through.... ... middle of paper ... ... Youtube.com (accessed 03/08/2014). Richardson, S. Water Analysis. Journal of Analytical Chemistry.
The factors for exponential growth for air-conditioning are the HVAC Market, energy, environment, communication, societal, political, preparing for the future, looking ahead, and the conclusion. Buildings of the U.S. use approximately 35% of the nation’s precise total of energy consumption. The worth of shipments by U.S. HVAC manufacturers was over $28 billion of 1996. Since there are 52,000 CHC chillers needed to be replaced among the U.S., there’s a large opportunity for new chillers, new technology for the HVAC industry. The ozone depletion is an international issue in which is currently being resolved. The 3rd world countries are still allowed to manufacture CFC’s. Illegal imports of CFC’S to the U.S. is a consistent concern. Many illegal imports are virgin CFC’s. Those whom have a political overtones are specifically the ones whom create a protectionism of local commerce, having a negative impact on those inside and out of the country.
Contamination of Water and Air. Urbanization enhances the proliferation of industries, automobiles, and agricultural practices. Most toxic air contaminants are produced as we endeavor to fuel our homes, automobiles, factories, energy production facilities, and might also be discovered in indoor cleansing mixtures, and construction supplies. Furthermore pollutants found in gasoline, dry cleaning services, and paint thinners and strippers; som...
Today's waters are constantly being treated like sewage dumps or trash cans. We use them as garbage cans every day polluting the water more and more. "Pollution is often by way of rivers, drains and outflow pipes." Causing an outflow of sewage into our ocean waters. This is not only affecting the community but also the marine life and other sea creatures living in the ocean." This pollution includes human sewage and domestic waste water, factory outflows of acids and poisonous metals, engine oil from roadside drains and garages, farm chemicals washed off the land by rain, building-site rubble, nuclear waste from power plants, and oil from wells, refineries, and tankers." Stating that most of today's waste is from factory or factory ran products that shouldn't be polluting the water
The methods that will be used for extracting volatile components include using a “sniffer.” The “sniffer,” otherwise known as a portable vapor detector, sucks in the air surrounding the questio...
Chemicals and impurities removed from water may not be disposed properly thus polluting the environment. A sheet volume of discarded filters may add up to landfill mass. The system itself may take up large amount of spaces and cause lots of noises and destructions. There may also be chemical or wastewater spills if not handled properly.
Asano, T., Burton, F., Leverenz, H., Tsuchihashi, R., Tchobanoglous, G. (2007). Water Reuse: Issues, Technologies, and Applications. New York: McGraw-Hill