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  2. Iron cycle - Wikipedia

    en.wikipedia.org/wiki/Iron_cycle

    Upwelling recycles iron and causes higher deep water iron concentrations. On average there is 0.07±0.04 nmol Fe kg −1 at the surface (<200 m) and 0.76±0.25 nmol Fe kg −1 at depth (>500 m). [21] Therefore, upwelling zones contain more iron than other areas of the surface oceans. Soluble iron in ferrous form is bioavailable for utilization ...

  3. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.

  4. Water cycle - Wikipedia

    en.wikipedia.org/wiki/Water_cycle

    The ocean plays a key role in the water cycle as it is the source of 86% of global evaporation. [2] The water cycle involves the exchange of energy, which leads to temperature changes. When water evaporates, it takes up energy from its surroundings and cools the environment. When it condenses, it releases energy and warms the environment.

  5. Iron-oxidizing bacteria - Wikipedia

    en.wikipedia.org/wiki/Iron-oxidizing_bacteria

    The anoxygenic phototrophic iron oxidation was the first anaerobic metabolism to be described within the iron anaerobic oxidation metabolism. The photoferrotrophic bacteria use Fe 2+ as electron donor and the energy from light to assimilate CO 2 into biomass through the Calvin Benson-Bassam cycle (or rTCA cycle) in a neutrophilic environment (pH 5.5-7.2), producing Fe 3+ oxides as a waste ...

  6. Deep water cycle - Wikipedia

    en.wikipedia.org/wiki/Deep_water_cycle

    Water carried into the mantle eventually returns to the surface in eruptions at mid-ocean ridges and hotspots. [8] This circulation of water into the mantle and back is known as the deep water cycle or the geologic water cycle. [9] [10] [11] [5] Estimates of the amount of water in the mantle range from 1 ⁄ 4 to 4 times the water in the ocean ...

  7. Iron in biology - Wikipedia

    en.wikipedia.org/wiki/Iron_in_biology

    Iron plays an essential role in marine systems and can act as a limiting nutrient for planktonic activity. [51] Because of this, too much of a decrease in iron may lead to a decrease in growth rates in phytoplanktonic organisms such as diatoms. [52] Iron can also be oxidized by marine microbes under conditions that are high in iron and low in ...

  8. Thermal power station - Wikipedia

    en.wikipedia.org/wiki/Thermal_power_station

    Air-cooled condensers typically operate at a higher temperature than water-cooled versions. While saving water, the efficiency of the cycle is reduced (resulting in more carbon dioxide per megawatt-hour of electricity). From the bottom of the condenser, powerful condensate pumps recycle the condensed steam (water) back to the water/steam cycle.

  9. Water-energy nexus - Wikipedia

    en.wikipedia.org/wiki/Water-energy_nexus

    Hybrid Sankey diagram of 2011 U.S. interconnected water and energy flows. The water-energy nexus is the relationship between the water used for energy production, [1] including both electricity and sources of fuel such as oil and natural gas, and the energy consumed to extract, purify, deliver, heat/cool, treat and dispose of water (and wastewater) sometimes referred to as the energy intensity ...