Carbon cycle carbonate

In a way, the oceans are carbons temporary resting place during the carbon cycle. Carbon atoms can stay in the oceans for several hundred years before returning to the atmosphere and continuing through the carhon cycle. 

In the course of the carbon cycle, carbon moves from the atmosphere, where it mostly exists in the form of carbon dioxide, into biological molecules—the molecules that make up living things and the wastes and remains. The incorporation of atmospheric carbon into living organisms begins with the process of photosynthesis. Some atmospheric carbon dioxide is also removed from the atmosphere when it dissolves in the cold ocean waters at the north and south poles. 

The influence of toxic substances on nutrient cycles can also be important. One of the more important nutrient cycles is the carbon cycle carbon from atmospheric carbon dioxide is fixed as organic carbon in plant biomass, biomass is consumed by organisms, and carbon in decaying biomass is released back to the atmosphere as carbon dioxide, with a concurrent release of phosphate, nitrogen, and other nutrients. Toxic substances may cause perturbations in such a cycle, as has been observed when toxic heavy metals in soil have killed populations of earthworms, which are important in biomass recycling. 

Figure 26-18 shows the carbon cycle. Carbon dioxide in the atmosphere is in equilibrium with an enormous quantity that is dissolved in oceans, lakes, and streams. Some of this dissolved CO2 was once in the form of calcium carbonate (CaC03), the main component of the shells of ancient marine animals. The shells were eventually converted into limestone, which represents a large store of carbon on Earth. When the limestone was exposed to the atmosphere by receding seas, it weathered under the action of rain and surface water, producing carbon dioxide. Some of this CO2 was released into the atmosphere. This process continues today. 

Junge, C.E., Schidlowski, M., Eichmann, R. and Pietrek, H., 1975. Model calcualtions for the terrestrial carbon cycle — Carbon isotope geochemistry and evolution of photosynthetic oxygen. J. Geophys. Res., 80 4542—4582. 

There are more than 1 million known carbon compounds, thousands of which are vital to life processes. The carbon atom s unique and characteristic ability to form long stable chains makes life itself possible. Elemental carbon is found free in nature in three allotropic forms amorphous carbon, graphite, and diamond. Graphite is a very soft material, whereas diamond is well known for its hardness. Curiosities in nature, the amounts of elemental carbon on Earth are insignificant in a treatment of the carbon cycle. Carbon atoms have oxidation states ranging from 4- IV to — IV. The most common state is +IV in CO2 and the familiar carbonate forms. Carbonate exists in two reservoirs. 

Figure 17.11 shows the carbon cycle in onr global ecosystem. The transfer of carbon dioxide to and from the atmosphere is an essential part of the carbon cycle. Carbon... 

Carbon Cycle. Carbon Dioxide (CO2) Cycie. Phosphorus Cycie. Radiocarbon. Stabie Carbon isotope Variations in the Ocean. 

Air-Sea Transfer Dimethyl Sulfide, COS, CS2, NH4, Non-Methane Hydrocarbons, Organo-Halogens. Carbon Cycle. Carbon Dioxide (CO2) Cycle. Nitrogen Cycle. Ocean Carbon System, Modeling of. Past Climate From Corals. Phosphorus Cycle. 

Figure 17.11 shows the carbon cycle in our global ecosystem. The transfer of carbon dioxide to and from the atmosphere is an essential part of the carbon cycle. Carbon dioxide is produced when any form of carbon or a carbon-containing compound is burned in an excess of oxygen. Many carbonates give off CO2 when heated, and all give off CO2 when treated with acid ... 

Carbonization Cycle. Carbonization is basically a heating cycle. The precursor is heated slowly in a reducing or inert environment, over a range of temperature that varies with the nature of the particular precursor and may extend to 1300°C. The organic material is decomposed into a carbon residue and volatile compounds diffuse outtothe atmosphere. The process is complex and several reactions may take place at the same time such as dehydrogenation, condensation and isomerization. 

The occurrence of CO2 on the earth should be regarded as an essential part of the carbon cycle. Carbon is to a large extent organically bound and stored in fossil fuels such as petroleum, natural gas and coal (cf Chapter 7). 

Patel, M., 1999, PhD thesis Closing Carbon Cycles Carbon use for materials in the context of resource efficiency and climate change. (ISBN 90-73958-51-2, http //www.library.uu.n1/digiarchief/dip/diss/l894529/inhoud.htm), Utrecht University, Utrecht, Netherlands. 

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