There are two types of fouling
(a) Macro fouling
(b) Micro fouling Figure 1.2: Heat exchanger in steam power plant fouled by macro fouling.
MACRO FOULING: Macro fouling is originated by the coarse matter of either biological or inorganic origin, for example industrially fabricated refuse particles. Such matter entering into the cooling water circuit through cooling water pumps from sources like the open sea, rivers or lakes. In closed circuits, cooling towers, the involvement of macro fouling into the cooling tower basin is only possible way through open canals or by the wind. Sometimes, parts of the cooling tower internals disengaged themselves and are carried into cooling water circuit. Such substances then foul the surfaces of heat exchangers and may cause degradation of their heat transfer coefficient. They may also generate flow blockages, redistribute the flow inside the components, or cause fretting damage.
Examples: manmade refuse, detached internal parts of component. Etc.
MICRO FOULING: There are several types of micro fouling, these are classified below
1. Scaling or precipitation fouling
2. Particulate fouling
3. Corrosion fouling
4. Chemical reaction fouling
5.
…show more content…
In such cases, the metallic surface occasionally acts as a catalyst. For example, corrosion and polymerization occurs in cooling water for chemical industry which has slight content of the hydrocarbons. Systems in petroleum processing are susceptible to the polymerization of olefins or accumulation of heavy fractions. High tube wall temperatures may steer to the carbonizing of organic matter. Food industry, for example milk processing, also experiences fouling issues by these chemical reactions. Fouling through an ionic reaction with an progression of an inorganic solid is commonly classified as precipitation fouling (not chemical reaction
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)
The purpose of this lab was to to cycle solid copper through a series of chemical forms and return it to its original form. A specific quantity of copper undergo many types of reactions and went through its whole cycle, then returned to its solid copper to be weighted. We observed 5 chemical reactions involving copper which are: Redox reaction (which includes all chemical reactions in which atoms have their oxidation state changed), double displacement reaction, precipitation reaction, decomposition reaction, and single displacement reaction.
...eading contributor of pollutants to lakes, rivers, and reservoirs…..Surface discharges can be caused by heavy storms or floods that cause storage lagoons to overfill, running off into nearby bodies of water. Pollutants can also travel over land or through surface drainage systems to nearby bodies of water, be discharged through manmade ditches or flushing systems found in CAFOs, or come into contact with surface water that passes directly through the farming area.
A chemical is a substance used in a chemical process.Everything that has mass is a chemical.Anything that is matter is a chemical. Filtration is the process of separating solid particles from fluids.To evaporate is to change from a solid or liquid to vapor.Alcohol is soluble in water.However, oil is insoluble in water.
A precipitation reaction can occur when two ionic compounds react and produce an insoluble solid. A precipitate is the result of this reaction. This experiment demonstrates how different compounds, react with each other; specifically relating to the solubility of the compounds involved. The independent variable, will be the changing of the various chemical solutions that were mixed in order to produce different results. Conversely the dependent variable will be the result of the independent variable, these include the precipitates formed, and the changes that can be observed after the experiment has been conducted. The controlled variable will be the measurement of ten droplets per test tube.
There are several different levels of purification, so the water can be reused for diverse purposes. Through only low levels of purifications treatments water can be reused for landscape, golf courses, and agricultural purposes. After intensive processing waste water can be used to supplement our drinking water supply. At the beginning this process the water is filtered to remove any large pieces in the water. Following that the water is then allowed to sit to and let small items sink to the bottom. For the items in the water that were not filtered out, or were able to sink are filtered out through the use of chemical reactions. The chemical processes used are called flocculation and coagulation. This process is used to clump together the particles that were to light to sink on their own. Some common compounds that are used to carry out these processes are aluminum sulfate, poly-aluminum chloride, ferric chloride, and ferric sulfate. During this process the chemical compounds react with the ions in the water to create precipitates; when the precipitate forms it will gather all of the particles in the water that were not able to sink on their own, and then both of the materials will settle to the bottom of the
The formation of the biofilm depends on factors like the type of surface used, presence of polymeric molecules on the surface and cell-cell interactions. Wastewater is passed through the surfaces on which the biofilms are attached. The microorganisms in the biofilm utilize the organic matter present in the wastewater and subsequently, the biofilms grow. There are four predominant reactor types that utilize this technology. Trickling Filters (TFs), Rotating Biological Contactor (RBC) Systems, Constructed Wetlands and Membrane Bioreactors (MBRs) (Sehar & Naz, 2016).
Next, these resources must be transported all over the world, where they will go into the preparation and refining stage. During this stage, there is a risk that refuse or sludge will result from coal cleaning parts (Lecture 3/11/02). Also, air and water pollution may result from the process of petroleum refining, which involves the change of the chemical composition of petroleum to produce desirable chemicals and fuels. However, that means that the undesirable results are released to pollute the atmosphere. (Lecture 2/22/02)
The bacteria and wastewater is mixed in an aeration tank and therefore the contaminants are removed by action of sorption and series of breakdown by the bacteria.
Investigating the Effects of Temperature on the Rate of Reaction between Magnesium and Hydrochloric Acid Introduction Chemical kinetics is the study and examination of chemical reactions regarding re-arrangement of atoms, reaction rates, effect of various variables, and more. Chemical reaction rates, are the rates of change in amounts or concentrations of either products or reactants. Concentration of solutions, surface area, catalysts, temperature and the nature of reactants are all factors that can influence the rate of reaction. Increasing the concentration of a solution allows the rate of reaction to increase because highly concentrated solutions have more molecules and as a result the molecules collide faster. Surface area also affects reaction rate because when the surface area of a reactant is increased, more particles are exposed to the other reactant.
The reaction of the metals with acids, the electrochemical fluctuations that happen in batteries and electrolytic cells, and the phenomena of corrosion are part of the focus of the heterogeneous reactions.
When the water comes into contact with the pyrite, the chemical reactions that take place causes the water to increase in pH which will dissolve heavy metals which stay in solution. However, when the pH levels reach a certain stage, the iron can then precipitate out, coating sediments with the characteristic yellow, red or orange colourings (D.E.P. 2, 2002; U.S.G.S.; U.S.E.P.A., 2002). The rate that A.M.D. advances is also influenced by the presence of certain bacteria (Doyle; U.S.G.S). A.M.D that has dissolved heavy metals such as copper, lead and mercury can contaminate ground and surface water. Especially at risk are mines that are located above the water table (Keller, 2000; D.E.P. 2, 2002). The sources of water that get polluted can be surface water that permeates into the mine, shallow ground water flowing through the mine or any water that comes into contact with the waste tailings produced by mines.
Chemical Weathering is when water weakens the structure of the rock and Mechanical Weathering is where water seeps into the rock face causing fragments of rock to break off.
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; some concentrations are presumed to cause cancers, or elevate other serious health risks. As a consequence these noxious air contaminants can be deposited in soils and water sources allowing them to be taken in by plants or swallowed by animals....
It is a relatively modern discipline which was employed since the mid-1980s as an alternative to pyrometallurgy in the recovery of base metals. The general characteristics that differ from pyrometallurgic processes are parameters such as lower operating temperatures, low reaction rates, lower environmental impact, low unit costs, selective chemical reactions and recycling of