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Methods of the separation of the base flow and trends of nitrogen concentrations in this base flow
MAIEROVÁ, Monika
This Bachelor thesis is aimed to clarify the hydrological cycle, hydrological balance, groundwater hydrology, the selected basic baseflow separation methods of comparing them and last but not least, nitrogen cycle, nitrogen, nitrates, ammonia nitrogen and nitrogen in groundwater. In the work there is also closely analyzed the total, surface and subsurface outflow and the detailed division. The methods of the groundwater baseflow separation are described with regard to content of nitrogen compounds., which currently create the most common type of pollution of groundwater used as drinking sources.
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Conclusion of study examining content of nitrates in basic species of vegetable distributed to the certain commercial network of merchandisers
RŮŽEK, Marek
The aim of this study was to examine content of nitrates as anti-nutritional factor in selected species of vegetable available in stores of Jindřichův Hradec. The study was carried out in years 2010 and 2011. Number of analysed samples reached 206. Due to the very wide range of vegetable diversity on the market the study was focused on basic categories. The green-stuff were represented by Chinese leaves and Iceberg lettuce, the root-vegetable by carrot, parsley and radishes. Finally there were put in test turnip cabbages and potatoes. The lowest amount of nitrates was determined in samples of root-vegetable except radishes and potatoes. Parsley contained 452 mg of NO3-.kg-1, carrot 241 mg NO3-.kg-1. The average of nitrate concentration in potatoes was 230 mg NO3-.kg-1. The other side of the scale occupied turnip cabbages containing 1982 mg NO3-.kg-1 in average.
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The Quality of Drinking Water in Public Distribution Systems
SOMPEKOVÁ, Zuzana
This research project was aimed at monitoring the quality of drinking water that is supplied to the inhabitants of small villages. The quality of drinking water produced by small waterworks in South Bohemia, in municipalities Mazelov, Ortvínovice, Doubravka and Rábín, was studied. Sanitary analyses of drinking water samples carried out by the waterworks operators in 2004-2009 showed some variability in the concentrations of free chlorine, nitrates, pH, turbidity and the content of Escherichia coli in all the waterworks during the investigated period. The hypothesis assuming that the quality of drinking water produced by water treatment from small water sources is stable and that it does not vary in some key indicators, such as nitrates, the contents of Escherichia coli etc., throughout the year was not confirmed. The other hypothesis assuming that the number of small water sources used for public drinking water supplies decreases during the period was confirmed. The causes of these changes depend on many factors, such as the location and source of drinking water, the type of treatment plant, and, last but not least, the quality of service and economic potential of the waterworks operators play a negative role.
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Monitoring and evaluation of nitrate content in root crops and cole crops distributed at retail outlets.
NOVÁKOVÁ, Jana
The object of this research was follow up the cumulation of nitrates in individual kinds of vegetables. Analysed was 240 samples of root crops, cole crops and potatoes distributed in the trade network in Humpolec in the years 2008 - 2010. The measurement results show that all the vegetables went beyond the nitrate permitted limit, according to a law n. 53/2002. The most frequently it was in potatoe samples (50 % samples). The next was a carrot (27 %), kohlrabi (25 %), broccoli (24 %) and celery (17 %). From aspect cumulation of nitrates is parsley unchallenged kind of vegetable. Permitted limit was transcendent in 10 % about less than 1 %. The origin of the vegetables was detected as well. Czech republic had the worst results (52,5 %) because of the high nitrate concentration in potatoes. It is grown by a domestic growers. Spain had 20 % in broccoli and kohlrabi. It is imported to our market. Although the high nitrate concentration in some vegetable samples the vegetable influence the human health in a positive way and it doesn?t make health hazard.
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Chemical hazards of contamination of foodstuffs and dishes
MARŠÁLKOVÁ, Alena
The bachelor thesis deals with the risks of chemical contamination of food and possible health risks for the consumers. Firstly, there is a general outline of foreign substances including the additives, which are added to foods intentionally, and contaminants. The contaminants are viewed as undesirable substances which occasionally occur in foods. They develop directly in the foods or penetrate into them from the outside during the basic stages of agricultural production, in stores, during transportation or during processing for culinary purposes, or due to environmental pollution. Such substances can have negative effects on human health. The second part of the thesis focuses on concrete contaminants - nitrates, nitrites and acrylamide. Nitrates and nitrites are both contaminants and additives. Their use as food additives is motivated by their sensoric and protective effects. The sensoric function is to ensure a permanent pink colour of smoked meat and other meat products. The protective function consists in inhibiting the growth of the microorganisms Clostridium botulinum and thus preventing the origination of dangerous botulin. The nitrates exist as contaminants mainly in foods of vegetable origin, penetrating them from soil and water due to nitrogen cycle in the nature. The acrylamide is a newly discovered food contaminant. It is considered to be a very dangerous substance as regards possible peroral exposure. The danger consists in its neurotoxic, genotoxic and possible carcinogenic effects. It originates in foods with a higher content of reducing sugars during the process of production or culinary processing if the temperature is higher than 120° C. The thesis should provide information for the public as consumers or providers of different food-processing facilities. Its main objective is to pinpoint some risks connected with the consumption of various foods and meals, and to eliminate the risks as much as possible or to avoid them completely.
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Analysis of time series of anions and cations concentrations in the Kopaninsky stream catchment in relation to land use.
KOUŘIMSKÁ, Kateřina
Water quality of small streams in agricultural landscape is mostly classified as polluted or very polluted. The reason of enhanced mineralization of organic mass in soil can be found in changed physical, chemical and biochemical properties of soil profile, which negatively display in mineralization of organic mass and nitrogen release to soil water. Analysis of water quality in agricultural river-basin prove that quality of surface water in areas with high nitrate loadings did not significantly improve in recent years. Nitrates in water are a distinct anthropogenic factor, which defines well disturbance in natural environment. This thesis deals with analysis of time series of nitrate concentrations in the Kopaninsky stream catchment in Bohemo-Moravian Highland. Further the progress in nitrate concentration and its seasonal component is researched.
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Comparison of precipitation and runoff in the research area Jenin in relation to nitrates.
ŠULCOVÁ, Lucie
The influence of precipitation on runoff characteristics of tile drainage systems and nitrate concentrations in drainage water were evaluated in this thesis. The Jeninsky stream catchment is located at the foothill of Sumava Mountains near the border checkpoint Dolni Dvoriste. Extensive agriculture (pasture) is practised in the catchment as well as surrounding areas. Above mentioned evaluated characteristics were measured on two closure profiles of tile drained subcatchments. Discharges were measured continously, water quality was sampled forthnigtly. Evaluated hydrologic year 2007 was rich in rainfall {--} the precipitation amounted to 892 mm, which is classified as a wet year, despite of 41 days long dry period. Runoff characteristics don{\crq}t vary much in both subcatchments, due to similar area and land use on researched catchments. Long dry period did not cause zero discharges. The progress of nitrate concentrations in subcatchments is characterized by low variations in values. Relatively low values (90-percentil of nitrate concentrations in individual catchments belong to II. and III. class of water quality limits set by Czech legislative) occured in the catchment. These values correspond or slightly exceed values monitored on surrounding simirarly used areas, but are significantly lower than values monitored in areas, where intensive agriculture is practised. This confirms positive influence of grassing on nitrate pollution of drainage and surface water.
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An experimental study of initial succession on different substrata: analysis of changes in plant species cover and some soil biological parameters and their relationships
KRESÁČ, Martin
A four year experimental study of initial stages of succession on different substrata (sand, peat and gray clay overburden from brown coal mining) was carried out. The substrata were transplanted into two different landscape types in the Czech Republic. Control plots were filled with autochthonous topsoil treated with high temperature vapor. Plots with un-treated autochthonous topsoil were also established. Plant species cover and several soil-biological parameters (soil microbial biomass, basal soil respiration, exchangeable pH(KCl), organic-C extractable by potassium sulfate solution, and nitrate-N content) were measured once a year. Obtained data were mainly processed by unimodal (plant cover data) and liner (soil-biological data) ordination methods. Biological species traits (life span, seed dispersal vector, seed bank type, ecological strategy type following Grime, life form following Raunkiaer) were used to characterize early stages of plant succession. Vegetation and measured soil-biological parameters, except pH(KCl), were significantly changing during four growing seasons. Variance partitioning analysis based on plant species cover data indicated the landscape type to be the main governing factor and physico-chemical characteristics of substrate to be less important during the studied initial stages of succession. The same analysis based on soil-biological parameters showed the reverse result. Great variability of plant species ecological traits was noticed during four growing seasons. The earliest plant colonizers were mainly ruderal, anemochorous terophytes with persistent seed bank. The number of species with C-strategy type increased during the study. The relationship between the average plant species cover and measured soil-biological parameters was also examined during the experimental study of early succession. Direct and indirect ordination revealed the average sum of plant species cover to be weakly positively correlated with soil microbial biomass, basal soil respiration, nitrate-N, potassium sulfate extractable organic-C, metabolic quocient (qCO2) and negatively correlated to exchangeable pH(KCl). The relationship was significant only in the case of microbial biomass and potassium sulfate extractable organic-C. More detailed studies of the relationship between aboveground plant species biomass and soil microbial communities in initial stages of succession are required. Comparability of presented study is limited because not many experimental investigations of similar kind have been presented until now.
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