Contamination degree

The quantity of superphosphate and ammonia sulfate is calculated by the phoshorus (8-10 mg/1) and nitrogen (12-40 mg/1) requirement of the bacteria. It depends on the contamination degree of the waste waters and their quantity by the formula ... 

Table 3.39. The criterion of the contamination degree and potential ecological risk...

This dependence can be used for evaluation of bacterial contamination degree for wool samples applying color standard scale [39]. 

Several title catalyst specimens with an identical Fe, K, Ca, and Cr content had been prepared from the different FeOOH or 6203 phases, and then tested at the same conditions in dehydrogenation of ethylbenzene to styrene. An influence has been discussed of the kind and the contamination degree of FeOOH or Fe 03 on the catalyst properties. The most selective but moderately active catalyst was obtained from p-FeOOH slightly contaminated with Cl which contained traces of a-FeOOH phase. The less selective but more active catalyst was obtained from pure a-FeOOH phase. 

Calcination of the initial mixture caused expected reduction in the specific surface areas. The reduction degrees seem not to be, however, in any relation with the kind or contamination degree of the FeOOH phase used. Nevertheless, the catalysts witi i higher specific surface areas could be obtained from amorphous or fine-crystalline FeOOH specimens. 

For the catalysts based on contaminated p-FeOOH more substantial decrease in selectivity has been observed only when p-FeOOH used was contaminated with more than 2 % Cl. If that oxide hydroxide was less contaminated, the lower decrease in activity, and particularly in selectivity, was observed with the Cl content increase. If the contamination degree did not exceed 0.7 % the selectivity decrease could be hardly observed. High selectivity of the catalyst based on the "pure" (i.e. least contaminated) )J-Fe00H suggest that Cl incorporated into (3-FeODH lattice cannot affect strongly the catalyst selectivity. 

It has been stated in this work that the kind and contamination degree of the initial iron compound used for the Fe-K/Ca-Cr catalyst preparation, which can be used in ethylbenzene dehydrogenation to styrene, exerted rather substantial influence on the catalyst activity and selectivity in the mentioned reaction. Hence, a proper selection of the kind of initial iron compound, as well as the selection of appropriate conditions for these compounds preparation can substantially help us to enhance the catalyst activity and selectivity. 

These systems have been operated in extremely low quality (and radioactivity contaminated) industrial environments for the past several years without any major equipment or component failures. Utilizing specialized operating/warm-up procedures, they have operated in low grade, out-of-doors, dust ridden, rain-soaked, industrial environments at temperature ranges which greatly exceed the original equipment manufacturers (OEM) specified limits. The systems have been successfully operated at ambient temperatures of minus 10 to plus 103 degrees Fahrenheit without any pre-mature or un-anticipated equipment failures. 

Process Concepts. Hybrid systems involving gas-phase adsorption coupled with catalytic processes and with other separations processes (especially distillation and membrane systems) will be developed to take advantage of the unique features of each. The roles of adsorption systems will be to efficiently achieve very high degrees of purification to lower fouUng contaminant concentrations to very low levels in front of membrane and other separations processes or to provide unique separations of azeotropes, close-boiling isomers, and temperature-sensitive or reactive compounds. 

Impurities. The chemical composition and properties of lime and limestone depend on the nature of the impurities and the degree of contamination of the original stone. The contaminating materials either were deposited simultaneously with the CaCO or entered during some later stage (6). 

Gas purification processes fall into three categories the removal of gaseous impurities, the removal of particulate impurities, and ultrafine cleaning. The extra expense of the last process is only justified by the nature of the subsequent operations or the need to produce a pure gas stream. Because there are many variables in gas treating, several factors must be considered (/) the types and concentrations of contaminants in the gas (2) the degree of contaminant removal desired (J) the selectivity of acid gas removal required (4) the temperature, pressure, volume, and composition of the gas to be processed (5) the carbon dioxide-to-hydrogen sulfide ratio in the gas and (6) the desirabiUty of sulfur recovery on account of process economics or environmental issues. 

Health and Safety Factors, Toxicology. Phosphoms trichloride severely bums skin, eyes, and mucous membranes. Contaminated clothing must be removed immediately. Vapors from minor inhalation exposure can cause delayed onset of severe respiratory symptoms after 2—24 h, depending on the degree of exposure. Delayed, massive, or acute pulmonary edema and death can develop as consequences of inhalation exposure. 

Phosphine generated by the above procedures is usually contaminated to varying degrees with diphosphine, which renders it spontaneously flammable. Pure phosphine can be produced by hydrolysis of phosphonium iodide [12125-09-6] PH I, which can be made by the action of water on a mixture of phosphoms and diphosphoms tetraiodide [13455-00-0] (71). 

Polyunsaturated fatty acids in vegetable oils, particularly finolenic esters in soybean oil, are especially sensitive to oxidation. Even a slight degree of oxidation, commonly referred to as flavor reversion, results in undesirable flavors, eg, beany, grassy, painty, or fishy. Oxidation is controlled by the exclusion of metal contaminants, eg, iron and copper addition of metal inactivators such as citric acid minimum exposure to air, protection from light, and selective hydrogenation to decrease the finolenate content to ca 3% (74). Careful quality control is essential for the production of acceptable edible soybean oil products (75). 

Siace the mid-1980s, contaminated storm mnoff has become an object of increasing concern within iadustrial complexes. Storm flow is intermittent and unpredictable ia aature, and tittle data has been collected to typify its characteristics. The level of flow and degree of contamination not only varies within an iastallation it has its own geometric characteristics, which influence patterns of surface mnoff. 

---