Soils sulfates

Cosby, B.J et al., Modeling the effects of acid deposition Control of long-term sulfate dynamics by soil sulfate adsorption, Water Resour. Res., 22, 1283, 1986. 

As discussed in Chapter 7, polluted air varies in composition from locale to locale and with the time of day and meteorological conditions in a given locale. Polluted urban air contains oxides of sulfur and nitrogen, carbon monoxide, ozone, uncombusted and partially combusted hydrocarbons from gasoline and diesel vehicles, and particulate matter. PM 2.5 particulates, the standard for evaluating pollution related to cardiovascular disease, are composed of combustion products, airborne soil, sulfates, nitrates, and heavy metals as listed in Table 29.4.141-45 ... 

In aerobic soils, sulfate (SOD is the stable form of sulfur. Strongly reducing conditions cause sulfate to be reduced biologically to hydrogen sulfide (H2S), a foul-smelling gas that dissolves readily in water according to the reaction ... 

Although the process requires the addition of a phosphate donor, such as glycerol-2-phosphate, it may be a valuable tool for cleaning water contaminated with radionuchdes. An alternative mode of uranium precipitation is driven by sulfate-reducing bacteria such as Desulfovibrio desulfuricans which reduce U(VI) to insoluble U(IV). When combined with bicarbonate extraction of contaminated soil, this may provide an effective treatment for removing uranium from contaminated soil (85). 

Copper. Some 15 copper compounds (qv) have been used as micronutrient fertilizers. These include copper sulfates, oxides, chlorides, and cupric ammonium phosphate [15928-74-2] and several copper complexes and chelates. Recommended rates of Cu appHcation range from a low of 0.2 to as much as 14 kg/hm. Both soil and foHar appHcations are used. 

Ma.nga.nese. Commonly used manganese fertilizer materials are manganous and manganic sulfates, chlorides, carbonates, oxides, frits, and chelates. Soil appHcation rates range from about 2 to 150 kg/hm of Mn. 

Manganese Ethylenebis(thiocarbamate). Maneb [12427-38-2] (C4HgMnN2S (1), is a yellow powder used as a leaf and soil fungicide (see Fungicides, agricultural). Maneb is obtained by treating disodium ethylenebis(dithiocarbamate) with an aqueous solution of maganese(II) sulfate (37). 

An additional mole of ammonium sulfate per mole of final lactam is generated duting the manufacture of hydroxylamine sulfate [10039-54-0] via the Raschig process, which converts ammonia, air, water, carbon dioxide, and sulfur dioxide to the hydroxylamine salt. Thus, a minimum of two moles of ammonium sulfate is produced per mole of lactam, but commercial processes can approach twice that amount. The DSM/Stamicarbon HPO process, which uses hydroxylamine phosphate [19098-16-9] ia a recycled phosphate buffer, can reduce the amount to less than two moles per mole of lactam. Ammonium sulfate is sold as a fertilizer. However, because H2SO4 is released and acidifies the soil as the salt decomposes, it is alow grade fertilizer, and contributes only marginally to the economics of the process (145,146) (see Caprolactam). 

Quantities of potassium sulfate produced and consumed as potassium magnesium sulfate [13826-56-7] K2S0-2MgS04, are omitted in the U.S. Department of the Interior reports as classified information. Consumption data for potassium compounds identified as other potassium salts imply that the amount of potassium magnesium sulfate consumed in the United States is about double that of K SO. This gap is expected to widen as soils become more depleted of natural magnesium- and sulfur-containing minerals. 

Ammonium sulfate is a good fertilizer for rice, citms, and vines, and can be especially useful for some sulfur-deficient or high pH soils. Nonfertilizer uses include food processing, fire control, tanning, and catde feed. 

Sodium nitrate is used as a fertiliser and in a number of industrial processes. In the period from 1880—1910 it accounted for 60% of the world fertiliser nitrogen production. In the 1990s sodium nitrate accounts for 0.1% of the world fertiliser nitrogen production, and is used for some specific crops and soil conditions. This decline has resulted from an enormous growth in fertiliser manufacture and an increased use of less expensive nitrogen fertilisers (qv) produced from synthetic ammonia (qv), such as urea (qv), ammonium nitrate, ammonium phosphates, ammonium sulfate, and ammonia itself (see Ammonium compounds). The commercial production of synthetic ammonia began in 1921, soon after the end of World War I. The main industrial market for sodium nitrate was at first the manufacture of nitric acid (qv) and explosives (see Explosives and propellants). As of the mid-1990s sodium nitrate was used in the production of some explosives and in a number of industrial areas. 

By-Products. The biomass from the fungal fermentation process is called mycellium and can be used as a supplement for animal feed since it contains digestable nutrients (25,26). The lime-sulfuric purification and recovery process results in large quantities of calcium sulfate cake, which is usually disposed of into a landfill but can find limited use in making plaster, cement, waUboard, or as an agricultural soil conditioner. The Hquid extraction purification and recovery process has the advantage of Htde soHd by-products. 

The manner in which many of these bacteria cany on their chemical processes is qmte comphcated and in some cases not fuUy understood. The role of sulfate-reducing bacteria (anaerobic) in promoting corrosion has been extensively investigated. The sulfates in shghtly acid to alkaline (pH 6 to 9) soils are reduced by these bacteria to form calcium sulfide and hydrogen sulfide. When these compounds come in contact with underground iron pipes, conversion of the iron to iron sulfide occurs. As these bacieria thrive under these conditions, they will continue to promote this reaction until failure of the pipe occurs. 

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