Ammonium sulfate treatment

Inorganic salts have long been known to provide flame retardancy on cellulosic material that will not be exposed to water, rain or perspiration. The French chemist Gay-Lussac proposed a borax and ammonium sulfate treatment as a flame retardant for cotton in 1820. Today, a mixture of boric acid and borax is still an effective flame retardant for cotton at 10 % solids add-on. Ammonium salts of strong acids, especially phosphoric acid (P/N synergism) are particularly useful as nondurable flame retardants for cellulose. Three commercially important products are diammonium phosphate, ammonium suifamate and ammonium bromide. These salts readily form the corresponding strong acids upon heating (Fig. 8.10). 

Catalysts obtained by treatment with sulfuric acid are usually more active than those obtained with ammonium sulfate treatment However, a recent study shows that the analogous activity is generated on S04/Zr02 by the kneading method with ammonium sulfate [60]. 

The third sample (Structure III) was the ultrastable Y material itself, Nao.5(A102)53(Si02)i39. It was obtained by calcination of the second sample at 870°C for 5 hours in a muffle furnace. The fourth sample studied (Structure IV) was a portion of the ultrastable material which was subjected to 2 additional cycles of 100 °C ammonium sulfate treatment followed by calcination for 5 hours at 870°C. By chemical analysis, this material had the same silica and alumina content as the second and third samples. 

In Structure IV, which is termed high-silica Y, the framework occupancy factors show that the repeated calcination and boiling ammonium sulfate treatment has restored all the framework atoms except for 12.5 of the 0(3) oxygen atoms. Sites Sn are occupied by 7.4 ions per unit cell. These ions, whose identity is not certain, have 3 framework 0(3) oxygens as nearest neighbors at a distance of 2.85 A. The mean Si,Al-0 bond distance of 1.610 (8) A is only 1 o- greater than the value of 1.603 A reported by Jones for a pure Si-O bond length (5). 

McDaniel and Maher have found that Step 3 of their procedure for making ultrastable Y is extremely important. They noted that treatment of the 540°C calcined, low-sodium oxide material (3% Na20) with a solution of ammonium sulfate at 100 °C for a prolonged period was essential to the stabilization step. In repeated experiments in which this material was subjected to only 2 cycles of 15 to 20 minutes each of boiling ammonium sulfate treatment, the molecular sieve collapsed upon high-temperature (810° to 927°C) calcination (9). 

F. D. Hunter You have several questions which I will try to answer. I think you are comparing Structure II and Structure IV. These structures are quite different. Structure II resulted from a 540°C calcination and then a rehydration owing to the ammonium sulfate treatment. Structure IV resulted from repeated 100 °C ammonium sulfate exchanges and calcination at 870°C. Hence, you are trying to compare a hydrated sieve to a calcined or dehydrated one. Also, since the framework aluminums are still missing in Structure III, they should be missing in II. 

Oxidative surface treatment processes can be gaseous, ie, air, carbon dioxide, and ozone Hquid, ie, sodium hypochlorite, and nitric acid or electrolytic with the fiber serving as the anode within an electrolytic bath containing sodium carbonate, nitric acid, ammonium nitrate, ammonium sulfate, or other electrolyte. Examples of electrolytic processes are described in the patent Hterature (39,40)... 

Ohio, high carbon ferrochromium is leached with a hot solution of reduced anolyte plus chrome alum mother Hquor and makeup sulfuric acid. The slurry is then cooled to 80°C by the addition of cold mother Hquor from the ferrous ammonium sulfate circuit, and the undissolved soHds, mostiy siHca, are separated by filtration. The chromium in the filtrate is then converted to the nonalum form by conditioning treatment for several hours at elevated temperature. 

Tetramethylisoindolenine (50) is obtained as an unstable, crystalline solid from the reaction of 2,5-hexanedione with 2,5-dimethylpyrrole in the presence of sulfuric acid. Treatment of the same diketone with ammonium sulfate also affords this isoindolenine. NMR measurements in deuteriochloroform indicate that a small amount of 1,3,4,7-tetramethylisoindole (51) is present in equilibrium with the isoindolenine. This same isoindole was postulated as an intermediate in the reductive self-condensation of 2,5-dimethyl-pyrrole (52) which affords a mixture of cis- and lwMs-l,3,4,7-tetra-methylisoindolines (53 and 54). Hydrolytic opening of the... 

Metals in contact with timber can be corroded by the acetic acid of the timber and by treatment chemicals present in it. Treatment chemicals include ammonium sulfate and ammonium phosphate flame-retardants. These are particularly corrosive towards steel, aluminum and copper alloys. Preservative treatments include copper salts which, at high timber moisture contents, are corrosive towards steel, aluminum alloys and zinc-coated items. 

From animal tissue, especially bovine lung and liver (e. g. autolysis of comminuted tissue parts, heating with ammonium sulfate in alkaline solution, filtration and acidification yield heparin as complex with protein, removal of fat with alcohol and treatment with trypsine for the purpose of decomposition of proteins, precipitation with alcohol and various purification methods). 

Treatment of the culture filtrate with increasing ammonium sulfate amounts showed that the bulk of polygalacturonase activity precipitates between 45 and 85 % ammonium sulfate saturation (Table 1). 

While the emphasis here has been on the reduction of the amount of waste sludges, it is also equally important to address the problem of regulating the effluents and emissions. In this context, special mention may be made of ammonia which must be carefully regulated. The procedure for processing ammonium fluoride or ammonium sulfate containing solutions begins with lime treatment. The filtrates are fed continuously into a column and stripped with live steam and upgraded. In this way it is possible (with improved equipment and carefully controlled operation) to attain ammonia contents of less than 50 ppm in the effluent. 

Conventional wastewater treatment techniques consist of physical/chemical treatments, including oil separation, dissolved gas flotation, and ammonia distillation (for removal of free cyanides, free sulfides, and ammonia) followed by biological treatment (for organics removal) and residual ammonia nitrification. Almost all residuals from coke-making operations are either recovered as crude byproducts (e.g., as crude coal tar, crude light oil, ammonium sulfate, or other sulfur compounds)... 

Perkin described a FR treatment for cotton using a mixture of sodium stannate and ammonium sulfate. 1912... 

The cell-bound amylopullulanase was solubilized with detergent and lipase. It was then purified to homogeneity by treatment with streptomycin sulfate and ammonium sulfate, and by DEAE-Sephacel, octyl-Sepharose and puUulan-Sepharose column chromatography (12). The final enzyme solution was purified 3511-fold over the crude enzyme extract with an overall recovery of 42% and had a specific activity of 481 units/mg protein. The average molecular weight of the enzyme was 136,500 determined by gel filtration on Sephacryl S-200 and SDS-PAGE, and it had an isoelectric point at pH 5.9. It was rich in acidic and hydrophobic amino acids. The purified enzyme was quite thermostable in the absence of substrate even up to 90°C with essentially no loss of activity in 30 min. However, the enzyme lost about 40% of its original activity at 95 C tested for 30 min. The optimum tenq)erature for the action of the purified enzyme on pullulan was 90°C. However, the enzyme activity rapidly decreased on incubation at 95°C to only 38% of the maximal 30 min. The enzyme was stable at pH 3.0-5.0 and was optimally active at pH 5.5. It produced only maltotriose and no panose or isopanose from pullulan. 

The ammonium sulfate is used to the extent of 97% in fertilizer. Other uses include water treatment, fermentation processes, fireproofing agents, and leather tanning. 

Figure 6. Affinity chromatography of EGD from Clostridium thermocellum. Nucleic acid preparation, heat treatment and ammonium sulfate precipitation (0-70%, 70-100%) were carried out as described (10). The final precipitate ( 50 mg protein), dissolved in 50 mM sodium acetate, pH 5.0, was applied (after centrifugation) on the affinity column (2 x 25 cm) (4 -aminobenzyl l-thio-/ -cellobioside coupled to Sepharose 4B) (11). Protein was monitored at 280 nm and the activity of the fractions (2 ml) determined using 2 -chloro-4 -nitrophenyl / -cellobioside (pH 6.5, 25°C) as described in the text. Elution with 10 mM G2 was started as indicated.

Natural (—)-actinidine (9a) is prepared from nepetalinic acid imide (262) via dichloropyridine (263) 403) and from iridodial (264) via bis (2,4-dinitrophe-nyl)hydrazone 404) or treatment with ferric ammonium sulfate (Scheme 19) 405). (+)-Actinidine (9b), the enantiomer of natural alkaloid, is synthesized from acid chloride 265, derived from (+)-pulegone, via vinylketone 267 (Scheme 20) 406). Racemic actinidine (9) is prepared by intramolecular cycloaddition of an acetylene across a pyrimidine ring in 5-(hept-5-yn-2-yl)-4,6-dihydroxypyrimidine (268) followed by chlorination and hydrogenation (Scheme 21) 407). 

Ammonium sulfate occurs in trace concentrations in the upper atmosphere. It is widely used as a fertilizer for rice and other crops. It is a source of sulfur for the soil. It is also used as an additive to supply nutrient nitrogen in fermentation processes (e.g., yeast production from molasses). It also is used for fireproofing timber and plastics, and in treatment of hides, and leather production. 

Native RNase is quite resistant to digestion with trypsin, even at a w/w ratio of 1 20, but small or unfolded fragments would be expected to be digested. When the synthetic enzyme was treated with trypsin, a 70% recovery of protein with a specific activity of 61% was obtained. Treatment of this material with saturated ammonium sulfate (diluted 16 26), pH 4.6, gave 33% of amorphous precipitate and 66% of soluble RNase A. The overall yield from the first Val residue was only 3%, but the specific activity was quite high at 78%. This is as far as the purification was carried out at that time. 

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