Plants absorption

O) Ditto, Vol 3, -Supplement Number Two to Volume 1 (1944). Chap I [Ammonia Oxidation Plant Rapid method for estimation of ammonia in gases entering the converter Laboratory control at Ammonia Oxidation Plant Absorption tower efficiency Ammonia oxidation conversion efficiency. Determination of small amounts of nitrogen oxides (Except NgO N203) in stack gases or in atmosphere] Chap I (Pickling of... 

In the single pressure plant, the oxidation and absorption steps take place at essentially the same pressure. In dual pressure plants, absorption takes place at a higher pressure than the oxidation stage. The oxidation and absorption steps can be classified as97 Low Pressure (Below 1.7 bar), Medium Pressure (Between 1.7 and 6.5 bar) and High Pressure (Between 6.5 and 13 bar). 

While SC>2 may be directly removed by rain [Beilke and Georgii (19)], plant absorption [Katz and Ledingham (134)], and direct deposition [Chamberlain (38)], the major sink is thought to be oxidation to sulfate. Though photoxidation in pure water appears to very slow [Robinson and Robbins (214)], the presence of metallic catalysts or dissolved ammonia produces very fast rates [Junge and Ryan (132)]. The photochemical oxidation of SC>2 in the presence of NC>2 and hydrocarbons has also been shown to produce considerable sulfuric acid aerosols [Schuck and Doyle (221)]. 

Plant roots absorb S almost entirely in the sulfate form. Thus, S applied to soils in other forms such as elemental S or as polysulfides, for example, must be converted to SO4 before plant absorption is possible. 1 he rate of conversion of non-sulfate compounds depends upon soil temperature, moisture, and particle-size distribution of the applied material. Under good grow-... 

Regeneration of high concentrations of sulfuric acid may also be achieved by addition of oleum or sulfur trioxide to diluted acid. The inventory of acid in circulation is increased by a corresponding amount (Eq. 9.26). A third method of reconcentration, useful when the acid consumption occurs as a part of, or adjacent to a contact sulfuric acid plant, is to pass the diluted acid itself through the acid plant absorption tower. This amounts to on-site addition of sulfur trioxide, and the increased acid inventory obtained can be sold to markets through the normal producer channels. 

Above-ground crop zone Evaporation Precipitation Irrigation Runoff Foliar application Volatilization from soil Drift Plant absorption Photodecomposition Drift Wash-off Condensation on soil... 

Column 3 shows the approximate annual plant uptake per hectare (ha) of the elements, assuming an annual dry matter production of 10 000 kg ha-1. The amounts of calcium, potassium, and nitrogen absorbed greatly exceed plant absorption of the other elements. 

An example of a chelating ligand is ethylenediaminetetraacetic acid (H4EDTA) and its many relatives (Fig. 3.4). The six positions around Fe2+ are occupied by the two amine and four acetate groups. Chlorophyll and hemoglobin are also chelates. Chelates are quite soluble and tend to keep Fe, Zn, and Cu in solution for plant absorption. Chelates are also used to extract microelement and heavy metal ions from soils. The stability constant of theFe(III)-EDTA complex is... 

During their evolution and course of life (ontogeny and phylogeny), plants have developed a number of biochemical mechanisms which have resulted in adaptation to and tolerance of new or chemically imbalanced growth media. Therefore, plant responses to trace elements in the soil and ambient air are variable in number and should always be investigated for a particular soil-plant system. The prediction of phytoavailability of trace elements is of a crucial importance for both crop production and health risk assessment. The influence of soil parameters and plant absorption ability are the main factors that govern the phytoavailability of an element. 

If the gas is to be compressed andiransported by sub-sea pipe line, then it may be necessary to remove carbon dioxide. If only a few per cent is present it is cheaper to transport the unwanted gas and remove it on-shore than to remove it off-shore. If, as with one North Sea field, the amount is 20 per cent, then removal off-shore is undertaken. The absorption process uses monoethanolamine and is basically the same as that on an ammonia plant. Absorption can also be used to remove water, and the re-usable absorbent which is cycled between absorption tower and regenerator is triethylene glycol. Water removal limits corrosion damage and prevents the formation of solid hydrocarbon hydrates which can plug gas lines. 

Pilot-Plant Absorption, Run No. Pilot-Plant Desorption, Run No. Conunercial-PIant Absorption, Run No. ... 

The Sulphur Cycle.— Unlike phosphorus, sulphur appears in both oxidised and reduced forms in the history of life. Completely oxidised as sulphate, it enters the plant from the soil, and is converted into partially reduced organic compounds containing the thiol group —SH or the disulphide linkage —S—S—. From these, the completely reduced form, HjS, is derived by bacterial degradation either in the soil or in the alimentary tract of the animal. Hydrogen sulphide is attacked by the sulphur-oxidising bacteria, with the ultimate formation of sulphate, which is available for plant absorption. 

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