National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Vliv obsádky na dynamiku hydrochemických parametrů v systému intenzivního chovu lososovitých ryb
Teplý, Martin
Aim of the thesis was to evaluate the influence of fish stock on the hydrochemical parameters of the water in Recirculating systems. A part of the work was elaboration of the literature review on the topic. In the experimental part was performed several trials under laboratory and practical conditions. The first trial aimed on comparison of hydrochemical parameters between recilculating system with biological filtration and recirculating system without biological filtration. There was studied a content of nitrogen compounds. The content of ammonia nitrogen was higher in the system without filtration (0.2 -- 1.0 mg.l-1) than in the system with biological filtration (0.1 -- 0.4 mg.l-1). In the system with the biological filtration was higher a content of the nitrite nitrogen ranged from 0.14 to 0.16 mg.l-1. In the system without filtration ranged content of nitrite nitrogen from 0.01 to 0.1 mg.l-1. In the next trial was monitored a development of the hydro chemical parameters in recirculating systems after their launch. Two monitoring was made. In the first three weeks was observed increased content of ammonium nitrogen, after its reduction increased nitrite nitrogen. These compounds were sufficiently degraded roughly after a one month. The third trial was aimed on changes in recirculating systems during 24 hours. Monitored were contents of nitrogen compounds, oxygen and pH. The lowest content of ammonium nitrogen was registered at night. The biggest increase of ammonium nitrogen was found after feeding of the fish. Content of nitrite nitrogen increased during monitoring due to biological degradation of ammonium nitrogen in filter. The biggest decrease of oxygen was registered after fish feeding. Oxygen decreased op to 10 percent. The pH continuously decreased during monitoring due to CO2 production of fish and biological processes in filter.
Evaluation of Decentralized Wastewater Treatment Systems: Sulfur as a Redox Indicator
DIÁKOVÁ, Kateřina
In this study, 13 decentralized wastewater treatment systems representing 4 design types were monitored during the summer and winter season. Inlet and outlet samples were analyzed for common water-quality parameters. Attention was paid to redox indicators, especially to sulfur oxidation forms.
Evaluation of Efect Mechanicle a Nitrifying Biological Filters in Recirculating Aquacultere Systeme with Intensive Fish Farming.
OLBERT, Karel
Aim of my work is influence of high level breeding of Euroasian perch on quality of water and operation of mechanicle drum filter and fluized bed biofilter. Euroasian perch is reared in recirculating aquaculture systeme. Fish were devide into six groups in dependence on their body weight. Groups of fish with avarage start weight (g) {$\pm$} SD; biomass (kg) 232,9 {$\pm$} 10,0; 15,14 (I), 196,4 {$\pm$} 8,1; 15,32 (II), 139,8 {$\pm$} 6,1; 15,10 (III), 102,4 {$\pm$} 5,5; 15,06 (IV), 59,4 {$\pm$} 5,5; 15,04 (V), 37,7 {$\pm$} 7,5; 15,00 (VI) were put into plastic tank (600l). Three measurement was with fed fish and three measurement with food-deprived fish. Fed day was organised like feeding period (light phase) 12 hours and 12 hours non-feeding period (dark phase). First part of my project was about impact mechanicle filtration to remove solids from water. Mechanical filter can keep the water quality on perfect level for fish farming. Second part was about evaluation of nitrifying biologickle filters. Biologicle filtration was did her function well, because levels of amonia, nitrite and nitrate were keep on optimum values. Third part of my project was about measurement of oxygen consumption and amonia excretion. Was observed significant diurnal changes of oxygen consumption and amonia excretion for fed fish. For food-deprived fish was observed significant diurnal changes of oxygen consuption. Changes of amonia excretion were not significant.

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