This has been observed in some unique settings, such as Little Bahama Banks and the deep Red Sea, but conditions of carbonate supersaturation and high suspended sediment loads may be common enough in coastal oceans that NICP may be an important factor in coastal carbon cycling. The goal of this project is to evaluate the significance of NICP caused by flood sediment and dust resuspension in coastal waters through a series of laboratory-based kinetic experiments as well as a series of instrumented coastal mesocosm experiments.
These in-situ mesocosm experiments take place in the coastal Red Sea at Eilat, Israel, to take advantage of the warm water temperatures, high CaCO 3 supersaturation, and large particle inputs from the surrounding desert.
Analysis and improvement of these experiments is underway, with a follow up field season planned for spring Co-advised by Dr. Chevallier IRD and Prof. Eric P. IFP Energies nouvelles is a French public-sector research, innovation and training centre. Its mission is to develop efficient, economical, clean and sustainable technologies in the fields of energy, transport, and the environment.
Its regular physical appearance is of a white powder. The main uses of carbonates is as raw materials in different industrial processes such as drug development, glass making, pulp and paper industry, sodium chemicals silicates , soap and detergent production, paper industry, water softener, clay and concrete production, among others.
Sodium Carbonate , known as soda ash, is a very important industrial chemical. It is mainly obtained by a method named Solvay process by the chemical reaction of limestone CaCO3 and sodium chloride NaCl.
Na 2 CO 3 common uses are in glass making, pulp and paper industry, sodium chemicals silicates , soap and detergent production, paper industry and water softener. Calcium Carbonate is the principal constituent of limestone a sedimentary rock and its pure state is obtained in three steps by the calcination of limestone and subsequent reaction with water and carbon dioxide.
Calcium Carbonate common uses are in glass, textile, paint, paper and plastic production, caulks industry, to produce ink and sealant. It is also used as a food additive non toxic , as a drug development and chalk production. Hard water is the term used in relation with high amount of inorganic compounds such as carbonates, bicarbonates, sulfates or chlorides in water.
The presence of high levels of carbonates and bicarbonates in water is denominated as temporary hardness of water. This is important when water is used for industrial process or cleaning purposes. The way precipitation is formed is when inorganic compounds in presence of high molecular organic compounds such as soaps produce undesirable insoluble precipitation. These precipitations are the responsible of a dirty or grayish white and low efficiency in cleaners.
Other way to form precipitation is when hard water attains high temperatures; its inorganic compounds such as calcium carbonate precipitates leaving a deposited coating in water pipes or over boilers.
Here is an example of what happens:. One way to reduce temporary hardness such as calcium ions is by boiling or by the addition of calcium hydroxide lime , but is not often used. The best way of soften water is by the addition of Soda Ash to the water or using an ion exchanged column. Some carbonates such as sodium carbonate or potassium carbonates are used to elaborate some detergents.
Soda Ash other name for sodium carbonate is used since in one way it is cheap and also it helps soften water by precipitation of calcium and magnesium carbonates. Potassium carbonates are used because of its solubility. Some inorganic compounds such as calcium carbonate, sodium carbonate and potassium carbonate are used as unprocessed material to elaborate glass since their chemical characteristics, high quality and low prices. In General Electric developed a process to make industrial-grade diamonds by treating graphite with a metal catalyst at temperatures of to K and pressures above , atm.
Although gem-quality diamonds can be synthesized, the costs involved are prohibitive. Both diamond and graphite occur as regularly packed crystals. Other forms of carbon are amorphous they lack a regular structure.
Charcoal, carbon black, and coke are all amorphous forms of carbon. Charcoal results from heating wood in the absence of oxygen. To make carbon black , natural gas or other carbon compounds are burned in a limited amount of air to give a thick, black smoke that contains extremely small particles of carbon, which can be collected when the gas is cooled and passed through an electrostatic precipitator. Coke is a more regularly structured material, closer in structure to graphite than either charcoal or carbon black, which is made from coal.
Carbides: Covalent, Ionic, and Interstitial. Although carbon is essentially inert at room temperature, it reacts with less electronegative negative elements at high temperatures to form compounds known as carbides. When carbon reacts with an element of similar size and electronegativity, a covalent carbide is produced.
Silicon carbide, for example, is made by treating silicon dioxide from quartz with an excess of carbon in an electric furnace at K. Covalent carbides have properties similar to those of diamond. Both SiC and diamond are inert to chemical reactions, except at very high temperatures; both have very high melting points; and both are among the hardest substances known.
SiC was first synthesized by Edward Acheson in Shortly thereafter, Acheson founded the Carborundum Company to market this material. Then, as now, materials in this class are most commonly used as abrasives. Compounds that contain carbon and one of the more active metals are called ionic carbides.
This model is useful because it explains why these carbides burst into flame when added to water. The ionic carbides that formally contain the C 4- ion react with water to form methane, which is ignited by the heat given off in this reaction. The ionic carbides that formally contain the C 2 2- ion react with water to form acetylene, which is ignited by the heat of reaction.
At one time, miners' lamps were fueled by the combustion of acetylene prepared from the reaction of calcium carbide with water. Interstitial carbides , such as tungsten carbide WC , form when carbon combines with a metal that has an intermediate electronegativity and a relatively large atomic radius.
In these compounds, the carbon atoms pack in the holes interstices between planes of metal atoms. They act as alloys, rather than as either salts or covalent compounds.
Although the different forms of carbon are essentially inert at room temperature, they combine with oxygen at high temperatures to produce a mixture of carbon monoxide and carbon dioxide. Because this mixture of gases is formed by the reaction of charcoal or coke with water it is often referred to as water gas. It is also known as town gas because it was once made by towns and cities for use as a fuel. Water gas, or town gas, was a common fuel for both home and industrial use before natural gas became readily available.
Eventually, as our supply of natural gas is depleted, it will become economical to replace natural gas with other fuels, such as water gas, that can be produced from our abundant supply of coal. CO and CO 2 are both colorless gases.
CO boils at Although CO has no odor or taste, CO 2 has a faint, pungent odor and a distinctly acidic taste.
0コメント