ammonium sulfate (American English and international scientific usage; ammonium sulfate in British English ); (NH 4 ) 2 SO 4 , is an inorganic salt that has many commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% sulphur .
Use
The primary use of ammonium sulphate is as a fertilizer for alkaline soils. The soil releases ammonium ions and forms a small amount of acid, thereby lowering the pH balance of the soil, while contributing to the nitrogen required for plant growth. The main disadvantage of using ammonium sulfate is its low nitrogen content relative to ammonium nitrate, which increases transportation costs. [2]
It is also used as an agricultural spray adjuvant for water-soluble insecticides, herbicides and fungicides. There, it serves to bind to the iron and calcium cations that are present in both well water and plant cells. It is particularly effective as an adjuvant to 2,4-D (amine), glyphosate, and glufosinate herbicides.
laboratory use
Ammonium sulfate precipitation is a common method of protein purification by precipitation. As the ionic strength of a solution increases, the solubility of proteins in that solution decreases. Ammonium sulfate is highly soluble in water due to its ionic nature, so it can “salt” proteins by precipitation. [3]Due to the high dielectric constant of water, the dissolved salt ions, cationic ammonium and ionic sulfate, readily dissolve within the hydration shells of water molecules. The importance of this substance in the purification of compounds stems from its ability to become more hydrated than the relatively large number of non-polar molecules and therefore desirable non-polar molecules to form and precipitate out of solution in a concentrated form. This method is called salting out and requires the use of high salt concentrations that can reliably dissolve in aqueous mixtures. The percentage of salt used is compared to the maximum concentration of salt that can be dissolved in the mixture. As such, although higher concentrations are required to serve to add salt abundances, more than 100%, can also precipitate the solution, therefore, contaminating nonpolar precipitates with salt precipitates.[4] A higher salt concentration, which can be achieved by adding or increasing the concentration of ammonium sulfate in solution, enables the separation of proteins based on a decrease in protein solubility; This separation can be achieved by centrifugation. Precipitation by ammonium sulfate results in a decrease in solubility rather than protein denaturation, thus the precipitated protein can be solubilized through the use of standard buffers. [5] Ammonium sulfate precipitation provides a convenient and simple means for fractionating complex protein mixtures. [6]
In the analysis of rubber lattice, volatile fatty acids are analyzed by precipitating the rubber with a 35% ammonium sulfate solution, leaving a clear liquid from which the volatile fatty acids precipitate with sulfuric acid and then by steam. are distilled. Selective precipitation with ammonium sulfate does not interfere with the determination of volatile fatty acids, unlike the usual precipitation technique using acetic acid. [7]
food additive
As a food additive, ammonium sulfate is generally recognized as safe (GRAS) by the US Food and Drug Administration, [8] and is designated by the E number E517 in the European Union. It is used as an acidity regulator in flour and bread. [9] [10] [11]
other uses
In drinking water treatment, ammonium sulfate is used in combination with chlorine to generate monochloramines for disinfection. [12]
Ammonium sulfate is used on a smaller scale in the preparation of other ammonium salts, particularly ammonium persulfate. Ammonium sulfate is listed as an ingredient for many United States vaccines according to the Centers for Disease Control.
A saturated solution of ammonium sulfate in heavy water ( D2O ) is used as an external standard in sulfur (33S) NMR spectroscopy with a shift value of 0 ppm .
Ammonium sulfate has also been used in flame retardant formulations that act like diammonium phosphate. As a flame retardant, it increases the combustion temperature of the material, reduces the maximum weight loss rate, and causes an increase in the production of tailings or char. [14] Its flame retardant efficacy can be increased by mixing it with ammonium sulfamate. It has been used in aerial firefighting. Ammonium sulfate has been used as a wood preservative, but due to its hygroscopic nature, this use has been largely discontinued due to problems associated with metal fastener corrosion, dimensional instability, and finish failures.
preparation
Ammonium sulphate is prepared by treating ammonia with sulfuric acid:
2 NH 3 + H 2 SO 4 → (NH 4 ) 2 SO 4
A mixture of ammonia gas and water vapor is introduced into a reactor containing a saturated solution of ammonium sulfate and about 2 to 4% free sulfuric acid at 60 °C. Concentrated sulfuric acid is added to keep the solution acidic and to maintain the level of free acid. The heat of the reaction keeps the reactor temperature at 60 °C. Dry, powdered ammonium sulfate can be made by spraying sulfuric acid in a reaction chamber filled with ammonia gas. The heat of the reaction evaporates all the water present in the system, forming a powdered salt. About 6,000 million tons were produced in 1981. [2]
Ammonium sulfate is also produced from gypsum (CaSO 4 2H 2 O). Finely divided gypsum is added to a solution of ammonium carbonate. Calcium carbonate precipitates as a solid, leaving ammonium sulfate in solution.
(NH 4 ) 2 CO 3 + CaSO 4 → (NH 4 ) 2 SO 4 + CaCO 3
Ammonium sulfate occurs naturally as a rare mineral in fumaroles in mascagnite volcanoes and caused by coal fires at some dumps. [15]
Property
Ammonium sulfate becomes ferroelectric at temperatures below -49.5 °C. At room temperature it crystallises in the orthorhombic system, with cell sizes of a = 7.729 , b = 10.560 , c = 5.951 . When cooled to the ferroelectric state, the symmetry of the crystal changes to the space group Pna2 1 .
reactions
Ammonium sulfate decomposes upon heating above 250 °C, first to form ammonium bisulfate. Heating to high temperatures decomposes into ammonia, nitrogen, sulfur dioxide and water. [17]
As a salt of a strong acid (H 2 SO 4 ) and a weak base (NH 3 ), its solution is acidic; The pH of 0.1 M solution is 5.5. The reactions in aqueous solution are NH 4 + and SO 4 -2 ions. For example, adding barium chloride precipitates barium sulphate. Filtration on evaporation yields ammonium chloride.
Ammonium sulfate forms several double salts (ammonium metal sulfate) when its solution is mixed with an equatorial solution of metal sulfates and the solution slowly evaporates. Trivalent metal ions form alum such as ferric ammonium sulfate. Double metal sulfates include ammonium cobaltous sulfate, ferrous diammonium sulfate, ammonium nickel sulfate known as Teuton’s salts, and ammonium ceric sulfate. [2] Anhydrous double sulfate of ammonium is also found in the Langbinites family. The ammonia produced has a pungent odor and is toxic.
Airborne particulates of evaporated ammonium sulfate account for about 30% of fine particulate pollution worldwide. [18]
legislation and control
In November 2009, a ban on Ammonium Sulphate, Ammonium Nitrate and Calcium Ammonium Nitrate fertilizers was imposed in the former Malakand Division -comprising Upper Dir, Lower Dir, Swat, Chitral and Malakand districts of North West Frontier Province (NWFP) of Pakistan, NWFP Government by, following reports that they were used by terrorists to make explosives. In January 2010, these substances were also banned in Afghanistan for the same reason.
Uses of Ammonium Sulphate
Synthetic ammonium sulfate fertilizers are white crystals, as cyan, brown or pale yellow in color made from coking or other petrochemical production by-products. The content of ammonium sulfate is 20.5-21% and contains a very small amount of free acid. It is easily soluble in water and has low hygroscopicity, but it can also absorb moisture and agglomerate in the rainy season, which will spoil the packaging bag. Pay attention to ventilation and dryness during storage. Ammonium sulfate is stable at room temperature, but when 4 alkaline substances act, it also releases ammonia gas, like all ammonium nitrogen fertilizers. After applying ammonium sulfate to the soil, it will gradually increase the acidity of the soil through the selective absorption of crops, so ammonium sulfate is similar to physiological acid fertilizer. Ammonium sulphate is suitable for normal soil and ready crops, And smells of ammonium-loving crops. It can be used as base fertilizer, top dressing and seed fertilizer. For binding fertilizer, it is more economical and effective to apply large amounts of nutrients to the soil near the root system during the first few days of crop growth. However, it should be applied when there are no water droplets on the stem and leaf surface to avoid damage to the crop. For rice, it should be added deeply or with cultivated fields to avoid chlorine loss due to nitrification and denitrification. The amount of ammonium sulfate as seed fertilizer should be low, generally 10kg per mu, 5-10 times mixed with decomposed organic fertilizer or fertile soil, be careful not to contact with the seed. While transplanting paddy, 5-10 catty of ammonium sulphate per acre, decomposed organic fertilizers, Can be mixed with superphosphate etc. to form a dilute solution, which is used to dip the roots of seedlings, and the effect is you a lot. In acidic soils, ammonium sulfate should be used with field compost, and with alkaline fertilizers such as calcium magnesium phosphate fertilizer and lime (not mixed application) to prevent soil acidity from rising. Application of ammonium sulphate fertilizer in the paddy field will generate hydrogen sulfide, which will blacken the rice roots, which is toxic to rice, especially when the dosage is large or applied to the old rating area, due to this poison. are more likely to occur. it happens. Use turtles and mix necessary measures such as farming and roasting fields. And you have a lot of influence. In acidic soils, ammonium sulfate should be used with field compost, and with alkaline fertilizers such as calcium magnesium phosphate fertilizer and lime (not mixed application) to prevent soil acidity from rising. Application of ammonium sulphate fertilizer in the paddy field will generate hydrogen sulfide, which will blacken the rice roots, which is toxic to rice, especially when the dosage is large or applied to the old rating area, due to this poison. is more likely to happen. it happens. Use turtles and mix necessary measures such as farming and roasting fields. And you have a lot of influence. In acidic soils, ammonium sulfate should be used with field compost, and with alkaline fertilizers such as calcium magnesium phosphate fertilizer and lime (not mixed application) to prevent soil acidity from rising. Application of ammonium sulphate fertilizer in the paddy field will generate hydrogen sulfide, which will blacken the rice roots, which is toxic to rice, especially when the dosage is large or applied to the old rating area, due to this poison. are more likely to occur. it happens. Use turtles and mix necessary measures such as farming and roasting fields. and should be used with alkaline fertilizers such as calcium magnesium phosphate fertilizer and lime (not mixed application) to prevent soil acidity from rising. Application of ammonium sulphate fertilizer in the paddy field will generate hydrogen sulfide, which will blacken the rice roots, which is toxic to rice, especially when the dosage is large or applied to the old rating area, due to this poison. are more likely to occur. it happens. Use turtles and mix necessary measures such as farming and roasting fields. and should be used with alkaline fertilizers such as calcium magnesium phosphate fertilizer and lime (not mixed application) to prevent soil acidity from rising. Application of ammonium sulphate fertilizer in the paddy field will generate hydrogen sulfide, which will blacken the rice roots, which is toxic to rice, especially when the dosage is large or applied to the old rating area, due to this poison. are more likely to occur. it happens. Use turtles and mix necessary measures such as farming and roasting fields.
The main uses of ammonium sulfate in agriculture are:
1. Used as base fertilizer for crops:
When ammonium sulfate is used as a base fertilizer, deep soil application is required to facilitate crop absorption.
2. Used as a top dressing for crops:
Ammonium sulphate is best suited to be used as a top dressing for crops. The amount of topdressing of ammonium sulphate should be determined according to the different soil types. For soils with poor water retention and fertilizer retention performance, it should be applied in stages, and the dosage should not be too high. For soils with good water retention and fertilizer retention, each dose should be appropriate.
Soil moisture content also has a greater impact on fertilizer efficiency, especially in dry lands. When applying ammonium sulfate, it is necessary to pay attention to timely watering. Like the paddy field for topdressing, it must first be dried and dried, and attention should be paid to the combination of tillage and application. In addition, there are also significant differences in the application of ammonium sulfate to different crops. For example, when used in fruit trees, it can be applied by ditching, ring application or acupoint application.
3, can be used as fertilizer when planting crops:
Because ammonium sulphate has no adverse effect on seed germination.
Things to note while using Ammonium Sulphate for sowing crops:
Note 1. Ammonium sulfate fertilizer should not be contacted or mixed with other alkaline fertilizers or alkaline substances to prevent reducing fertilizer efficiency.
Note 2. It is not advisable to apply ammonium sulphate for a long time on the same piece of cultivated land, otherwise the soil will turn sour and may cause compaction. If it is necessary to apply, some lime or organic fertilizer can be applied in appropriate amounts. However, it should be noted that ammonium sulfate and lime cannot be mixed so as to prevent the decomposition of ammonium sulfate and the loss of nitrogen. Generally, the combined application of the two should be separated by 3-5 days.
Note that ammonium trisulfate is not suitable for application on acidic soils.
