Isolation studies, waste

PAN was for a long time thought to be resistant to microbial attack. However, various bacteria that produced nitrile-converting enzymes were isolated from waste-waters of factories producing PAN fibre. Eor example, a nitrile hydratase/amidase enzyme system was studied from Mesorhizobium sp. E28 [68]. Also, bacteria (namely Ralstonia solanacearum and Acidovorax avenae) were used for the removal of acrylic acid from such waste-waters [69]. Later, on the basis of NMR... 

Natural systems have been studied to provide data to support the ability of geological repositories to isolate radioactive wastes (e.g.,... 

Transuranic Waste. Transuranic wastes (TRU) contain significant amounts (>3,700 Bq/g (100 nCi/g)) of plutonium. These wastes have accumulated from nuclear weapons production at sites such as Rocky Flats, Colorado. Experimental test of TRU disposal is planned for the Waste Isolation Pilot Plant (WIPP) site near Carlsbad, New Mexico. The geologic medium is rock salt, which has the abiUty to flow under pressure around waste containers, thus sealing them from water. Studies center on the stabiUty of stmctures and effects of small amounts of water within the repository. 

Erdal, B.R. Aguilar, R.D. Bayhurst, B.P. Daniels, W.R. Duffy, C.J. Lawrence, F.O. Maestas, S. Oliver, P.Q. Wolfsberg, K. "Sorption-Desorption Studies on Granite. I. Initial Studies of Strontium, Technetium, Cesium, Barium, Cerium, Europium, Uranium, Plutonium, and Americium", in "Proceedings of the Task 4 Waste Isolation Safety Assessment Program Second Contractor Information Meeting", Vol. II, Report PNL-SA-7352, Battelle Pacific Northwest Laboratory, 1978, pp. 7-67. 

The number of reports about hemicelluloses that have been covered by this review indicates the significantly increased importance of all types of hemicelluloses as plant constituents and isolated polymers during the last decade. Attention has been paid not only to known hemicelluloses but also to the primary structure, physicochemical, physical, and various functional properties of hemicelluloses isolated from hitherto uninvestigated plants. The efforts to exploit a variety of plant as potential sources of hemicelluloses were pointed out particularly for agricultural crops, wood wastes, as well as for by-products of pulp and rayon fiber technologies. Many studies were devoted to characterize seed-storage hemicelluloses from plants that have been traditionally applied in food and medicine of many underdeveloped countries to find substitutes for imported commercial food giuns. 

According to a study by the World Health Organisation, viruses have been found to survive chemical treatment in aircraft toilets. Researches reported that up to half the samples of waste pumped from on-board toilets contained viruses despite the use of toilet sanitiser. All the viruses isolated from the waste were associated with enteric disorders. This indicates that other viruses such as those that cause hepatitis could also survive. As a consequence, future products will need to be even more effective as it is believed that between 1-10% of viruses survive to be potentially discharged into the environment. 

The identification and structural characterization of biological materials, obtained for example from plants, was traditionally carried out via the classical sequence involving extraction, separation, isolation and characterization, a sequence which requires large amounts of substance and a great deal of time. Industrial problems, for example the search for small amounts of contaminants in industrial products or in waste water, also require intensive analytical studies. 

After isolating the product of a solid phase synthesis, the support (resin + linker) is usually discarded as waste, although successful examples of its reuse in further synthetic cycles are known with trityl type linkers (Frechet and Haque 1975). To reduce both volume of operation and amount of waste, the loading of the resin (quantified as millimoles of functionality per gram) has to be increased. Besides theoretical limitations (for polystyrene this is reached when every phenyl ring is substituted by the linker), there may be practical boundaries for using highly loaded resins in solid-phase supported synthesis. This issue was studied... 

Effect. There are no specific disease states in humans or animals that have been associated with exposure to 3,3 -dichlorobenzidine. Hemoglobin adducts have been isolated from the blood of 3,3 -dichlorobenzidine-treated animals (Bimer et al. 1990 Joppich-Kuhn et al. 1997). It is not known what relationship exists between adduct levels in the blood and 3,3 -dichlorobenzidine toxicity. Further research in animal models is needed to determine if these adducts could be correlated with effects of 3,3 -dichlorobenzidine exposure. Further studies to identify more sensitive toxic effects (noncancer) that are specific for 3,3 -dichlorobenzidine would be useful in monitoring effects in people living near hazardous waste sites containing 3,3 -dichlorobenzidine. 

Sensitivity and reaction path analyses also represent techniques to identify rank-order of importance of reactions in the mechanism. Important reactions can then be isolated and studied with greatest scrutiny, without wasting scarce resources on unimportant ones. As new and improved data on important elementary reactions become available, they are reincorporated into the evolving mechanisms. Revised mechanisms are then resubjected to sensitivity and reaction path analyses for the redetermination of the rank-order of importance of reactions. 

A study showed the collapse of a population of fish in an isolated lake spiked with relatively high levels of the synthetic oestrogen 17a-ethinylestradiol [116]. Other studies on aquatic populations in a waste-impacted stream in Boulder, Colorado, showed reproductive effects from estrogenic wastewater effluent [117]. 

The results of this study are summarized in Table 4. The product is isolated by filtration of the reaction mixture through a silica column, thus avoiding an aqueous waste stream. 

Before the availability of artificial fertilizers in the mid-19th century, farms were traditionally organic, with recycling of animal waste, and perhaps with the application of lime on acid soils. Agricultural chemical analysis may have begun with Carl Wilhelm Scheele (1742-1786), the Swedish pharmacist who isolated citric acid from lemons and gooseberries and malic acid from apples. In France, Nicolas Theodore de Saussure (1767-1845) studied the mineral composition of plant ash, and in Britain, Sir Humphrey Davy... 

The authors would like to thank M. Cuney, R. Giere, and an anonymous reviewer for the very helpful comments. This study was partly financially supported by JNC, Waste Isolation Research Division, Tokai-mura, Japan. This is EOST/CGS contribution no. 2004.601-UMR7517. 

Data from the evaluation and Proof of Concept studies indicated that the anticipated process benefits could be realized, and, with the inclusion of the racemization process, the expected environmental benefits could also be achieved. For example, this procedure avoided the use and recovery of DTTA, the desired (S,S)-enantiomer could be isolated in >90% yield, and a productivity of 5 kg of racemate per kg of CSP per day could be achieved (an above-average value for MCC). Solvent recovery and re-use for the MCC was predicted to be >99.5%, and the only solid waste would be the spent/exhausted CSP. 

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