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The nitrate content of some foods was determined. Canned food, baby food, frozen food, and fresh vegetables were analyzed. Among them spinach and beet were found to have the highest nitrate-nitrogen content and frozen food had higher nitrate-nitrogen content than other food products analyzed. Nitrate-nitrogen of food is partially transferred to the liquid portion whenever the food consists of any liquid. The amount of nitrate in the liquid portion seemed, to be higher than in the solid portion except in bean which has a protective surface layer as a factor of lowering the nitrate found in the liquid portion. The rate of nitrate transferring from solid portion to liquid portion was not the same for all foods and was not the same even from different parts of the same plant. Nitrate-nitrogen was not destroyed by cooking. Even after pouring off cooking water, some nitrate-nitrogen still remained in the solid portion. The distribution of nitrate among different plant parts was not uniform: bean leaves, beet root and spinach petioles were found to have higher nitrate than other parts. Nitrogen fertilization readily increased nitrate-nitrogen content in spinach. The sodium salicylate method was found to be the most reliable method for nitrate determination among different methods used in this study. The determination might be affected by many factors occuring during the procedure of analysis such as procedure of extraction and the spectrophotometer blanks used. Oxidising agents, arid reducing agents do not seem to affect the analysis but pH variation and sucrose which might occur in food probably are factors affecting apparent nitrate content. Cooking did quickly destroy spinach nitrate reductase enzyme activity. This means that nitrite will not be found after cooking unless the enzyme is regenerated, or unless there is microbial activity. / Land and Food Systems, Faculty of / Graduate

Jackson Blue is a first magnitude spring in the karst terrane of northeast Florida. Previous studies have identified inorganic fertilizer as the source of high nitrate levels in the spring. Agricultural land use and karst vulnerability make Jackson Blue a good model for conservation concerns. This work offers an aggregation of studies relating to the springshed, providing a valuable tool for planning and conservation efforts in the region. An analysis of nitrate levels and other water quality parameters within the springshed did not reveal significantly different values between agricultural and forested land use areas. Confounding factors include: high transmissivity in the aquifer, interspersed land use parcels, and fertilizer application in forested areas due to commercial pine stand activity.

The subject of this thesis is a description of various types of mathematical models aimed at the spread of pollution in the river downstream and selection of the most suitable type of model and design the new one with using MATLAB. The application of the model is performed on Karlický creek, where it will be put into operation a new wastewater treatment plant Vysoký Újezd. Using the assembled model there are presented three simulation studies showing the dependence of time on the concentration of nitrate. These are:  Simulation of accident of the wastewater treatment plant Vysoký Újezd  Excessive intake of nitrate caused sheet erosion from adjacent agricultural land  Combination of both simulations Individual studies present the effect of nitrate on the water quality in Karlický creek, which falls into two categories of protection, Český kras area and Nature Reserve Karlické údolí. The aim of the above simulation studies is to demonstrate the spread of the nitrate into the various compartments along the entire length of the watercourse, and to show the loss of the nitrate over time and to compare the effects of point and diffuse sources of pollution. The model is calibrated according to the samples taken in Karlík creek during the period from 30 June 2008 to 31.12. 2009th . The results of...

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The purpose of this study was to investigate the polymorphism of a group of related compounds. Special emphasis was placed upon the temperature at which transitions occurred and a possible correlation of these temperatures with other properties of the compounds.

Call number: LD2668 .T4 1966 H294 / Master of Science

The stable isotopes of the conservative element boron, 11B and 1°B, have been employed as co- migrating isotopic tracers to determine the origin of nitrate observed in groundwater from a large capacity (2500 gpm) irrigation well in the Avra Valley of southeastern Arizona. The isotopic ratios of the conservative element, boron, provided an identifying signature for various nitrate rich source waters. Additional chemical parameters were also examined to corroborate the isotopic indications. Findings of this investigation indicate that most of the nitrate observed in groundwater from well CMID 18 at the beginning of the 1993 irrigation season was due to municipal wastewater contamination. As the irrigation season progressed, an increasing proportion of nitrate was contributed by irrigation return flow from neighboring agricultural fields.

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No description available.