Sulfate release

Over the past decades, advances have been made that reduce environmental impacts of coal burning in large plants. Some arc standard and others experimental. Limestone (mainly calcium carbonate) scrubber smokestacks react with the emitted sulfates from the combustion and contain the chemical products, thereby reducing the release of SO., into the atmosphere by a large factor (of ten or more). Pulverization of coal can also allow for the mechanical separation of some sulfur impurities, notably those in the form of pyrites, prior to combustion. Currently deployed—with more advanced versions in the development stage—are various t yies of fluidized bed reactors, which use coal fuel in a pulverized form, mixed with pulverized limestone or dolomite in a high temperature furnace. This technique reduces sulfate release considerably. There are... 

A flowsheet for the Wellman-Lord process is shown in Figure 25.26. Again the gas stream with S02 enters a scrubber into which is sprayed a sodium sulfite solution. This then goes to an evaporator/crystallizer to crystallize out the resulting sodium bisulfite, which converts the sodium bisulfite back to sodium sulfate, releasing the S02. The crystals are dissolved in water and recycled to the scrubber. The effect of the Wellman-Lord process is to produce a concentrated S02 stream from a dilute S02 stream. The resulting concentrated S02 still needs to be treated. 

In the context of the desirability of removing sulfur compounds from fuels, a bacterial strain has been identified that will metabolize thianthrene to water-soluble products under aerobic conditions (83MI5). A thermophilic organism, Sulfolobus acidocaldarius, removed 38% of the sulfur, as measured by sulfate release, in 4 weeks at 70°C (87MI2). 

J.W.McGinity, L.A.Hunke and A.B.Combs, Effect of water soluble carriers on morphine sulfate release from a silicone polymer,/. Pharm. Sci., 68,662 664 (1979). 

Even in summer, the S concentration is highest at the center station, and the concentration at the west station is only about 30% below that at the east station. The fact that concentrations are highest at the center station may be related to the fact that the east station is more distant from the Ohio River and the highest density of coal-fired plants (see Figure 1). This suggests that there may be appreciable primary sulfate released by those plants, or that sulfate conversion is faster than we normally assume. In anv case, there is clearly not a strong build-up of particulate S as air masses move up the ORV from the southwest. 

Some difficulty was experienced in establishing a strict correlation between liberation of amino group and sulfate release. For example, Wolfrom and McNeely, and Jorpes, Bostrom and Mutt, did not obtain correspondence between these when heparin was treated with hot, dilute acid. It was suggested that retention of the barium sulfate in the colloidal state (peptization) by the heparin might be responsible for inaccurate results in sulfate analysis. If, however, heparin was first treated with hot, dilute alkali, then, on subsequent acid treatment, correspondence between release... 

Similarly, McGinnity has shown that incorporation of hygroscopic carriers such as sodium alginate into silicone rubber based matrix devices greatly inaeased the rate of morphine sulfate release and changed its temporal character to approximate more nearly a zero-order pattern. It was noted that inclusion of a carrier caused the device to swell considerably because of water imbibition and no doubt a complex series of events account for the effect on release rate. 

Ammonium sulfate releases [1] ammonia above 523 K in an endothermic reaction ... 

Other potential forms of copper include sulfide, hydroxide, oxide, and carbonate forms. Under reducing conditions, copper sulfide is formed. Sulfides are stable under anaerobic conditions. Sulfides can be oxidized with electron acceptors of higher reduction potentials by sulfide-oxidizing bacteria to form sulfate, releasing the metal ion back into the solution. Under alkaline conditions, the hydroxide, oxide, or carbonate can be formed so that dissolved copper ions can be removed from the solution and precipitated in this form. 

Gentamicin sulfate release from antimicrobial fibres was carried out by submergiiig the fibre-gentamicin sulfate complex into a physiological solution (0.95% NaCl). After that, gentamicin sulfide release was monitored. Gentamicin sulfate release fix>m the fibre (physiological solution) was measured in vitro by a Shimadzu UV-260 UV-vis spectrophotometer. 

We suggest that in some propionibacteria sulfate release into the medium, which is dependent on the intracellular sulfate pool, can serve as a regulatory mechanism for the latter. It cannot be excluded, however, that alternations between sulfate uptake and release are the result of a number of interdependent processes in the cell, forming circadian rhythms. In particular, sulfate can be produced in the reaction catalyzed by APS-ammonium adenylyl transferase, which represents an exchange of the sulfo group of adenosine 5-phosphosulfate for an amino group in this reaction... 

Effect of CA on In-vitro gentamicin sulfate release of core/shell electrospun PEG/PLA mats... 

An interesting method has been exploited for the detection of contamination in foodstuffs and tap water by Escherichia coli. It is based on detection of 2-NP that is released from hydrolysis of o-nitrophenyl-/ -D-galactopyranose as catalyzed by / -galactosidase, an enzyme present in most strains of E. coli. Maximum enzyme activity was observed in phosphate buffer with addition of sodium dodecyl sulfate released 2-NP was detected at bare BDD electrode. The detection limit was 4x10" cells mL with a total analysis time of <1.5 h. 

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