Auswahl der wissenschaftlichen Literatur zum Thema „Zpracování zemědělských odpadních vod“

This thesis deals with an agricultural wastewater treatment (liquid digestate) by membrane technology. There is a fundamental description of characteristics of membrane technology with regard to application of agricultural wastewater treatment in this thesis. Experimental device for treatment of liquid digestate is designed and it consists of three steps – microfiltration, ultrafiltration and reverse osmosis. The first step consists of four filters with different pore sizes (80, 25, 10 and 5 µm). The second step is ultrafiltration and the third and key step is reverse osmosis. In the final step monovalent ions such as NH4+ are separated. Reverse osmosis consists of two stage system which results in higher recovery. Three experiments were carried out in order to verify the efficiency of separation dissolved solids.

The contens of diploma thesis is description of paper and pulp production and analysis of contemporary problems with disposal of sludges rising on industrial waste water treatment plant. Accent is focuses on description of waste water treatment technique, characteristics of rising sludge and the ways of his liquidation in particular plant for pulp production. Fundamental part of this project is evaluation of power and economics balance of current sludge technology in company Biocel Paskov a.s. and suggested sludge management technology. Balances are based on data gained from measurement in laboratory and on data gained from literary research.

The first part of the thesis is focused on the problems related to sludge and evaluates sludge disposal from waste treatment plants. The thesis mentions factors influencing method selection of sludge disposal as well as it compares sludge disposal in the Czech Republic and in the other states of the EU. It describes a complete waste treatment line and sludge disposal in the area of sludge treatment and disposal. It deals with sludge disintegration and describes the most effective methods of disintegration. The second part of the thesis describes an experimental part of disintegration of waste treatment sludge. An experiment was conducted in the school laboratory in a way of thermal disintegration in the double-surface pressure tank. The disintegration was conducted to temperatures of 60 °C, 90 °C, 120 °C, 150 °C, and 180 °C. We monitored dependence of the sludge dry residue content on disintegration temperature as well as content of suspended solids in liquid fraction (FUGAT). It was possible to choose optimal temperature of disintegration in accordance with processed results.

This diploma thesis is focused on sludge management of wastewater treatment plant. The research work contains an overview of the related legislation, outlines the problems of sludge treatment in the Czech Republic and also deals with technologies and technical solutions that are related to the processing and treatment of sewage sludge for various size categories of wastewater treatment plants. The second part is devoted to the technical and economic assessment of wastewater treatment plants in the category from 500 EO to 2 000 EO. The assessment is based on real data provided by WWTP operators and focuses on electricity consumption, investment costs and operating costs. Part of the diploma thesis is also determining the rentability of drainage equipment, and studying the convenience of using mobile or stationary drainage equipment.

The diploma thesis deals with a six-month monitoring and changes of water chemism in tanks of sugar factory in Hrušovany nad Jevišovkou. The monitoring was carried out between 17 April 2018 and 3 October 2018 for 3 sedimentation tanks and 1 accumulation tank. It was carried out outside of the main beet campaign. At the time of sampling from the tanks, values of the following quantities were recorded: pH, temperature, conductivity and transparency of the water. In next 24 hours the total amount of nitrogen, the amount of nitrogen in nitrites, nitrates and ammonia, as well as the total amount of phosphorus, the amount of orthophosphates, chemical oxygen demand, biochemical oxygen demand, acid and base neutralisation capacity, the amount of calcium, iron, chlorides, insolubles and chlorophyll a were determined in the laboratory of fisheries and hydrobiology Department at Mendel University based in Brno. The values of the indicators varied according to the season, the amount of the discharged waste floating and washing water and the temperature. The highest values of the pollution in average were determined for the sedimentation tank n. 1, to which more waste water had been launched in 2017 because of the yield sediment. The highest values there were for the indicators as the total amount of nitrogen 307,9 mg/l, the amount of nitrogen in ammonia 117 mg/l, chemical oxygen demand 11600 mg/l, biochemical oxygen demand 8200 mg/l and the amount of insolubles 1510 mg/l. However, the high values for the sedimentation tanks are not a major problem as they are getting lower during the year due to the digester sludge and its sedimentation. Also important fact is, that the water in the sedimentation tanks is being overflowed to the accumulation tank, where it is diluted and may be adjusted if needed. Then it is possible to drain the purified water from the accumulation tank to the river Jevišovka (IDVT 10100035), but parameters of the water need to meet the limits of Government Regulations n. 401/2015 Sb. If the values are higher than those limits (as it was found for the monitoring described in this diploma thesis), there is a baffle built near the draining mechanism of the accumulation tank, so the water may be adjusted there in a smaller amount. However, the sugar factory in Hrušovany nad Jevišovkou has never drained the water from the accumulation tank to the river Jevišovka, because of the fact that 50 cm of the water column evaporates from all 4 tanks each year. The baffle was built just because of preliminary experiments of effective purifying the waste water, that could be drained to the river in the future. The values of the parameters of the water from the accumulation tank were compared with the results gained in 2010, 2012, 2014 and 2016 in the same 2 months of sampling. The results of those 5 measurements are also compared to the permissible values stated by the Government Regulations n. 401/2015 Sb.

The thesis deals with the analysis of corrosion resistance of machinery used in wastewater treatment plants. The theoretical part of the thesis deals with the composition of waste water in terms of corrosion aggressiveness and describes the corrosive en-vironment in the WWTP. Furthermore, the types of corrosion are characterized and the exposed machinery of the WWTP with the highest level of corrosion is determined. The experimental part of the work is devoted to the analysis of corrosion resistance of corrosion-resistant austenitic steels and structural non-alloyed steels with duplex zinc coating and acrylate paint. Furthermore, structural low-alloyed steels with chemical-heat treatment by nitriding and ferritic nitrocarburizing in gas and structural non-alloyed steel with duplex system of phosphate + epoxy coating and zinc + epoxy coating are analysed as a possible replacement for stainless steels. The steels with duplex system of zinc + acrylate coating used in practice show little corrosion resistance (the first signs of corrosion after 12 h and 24 h). some chemical-heat treated steels and steel with duplex sys-tem of zinc + epoxy coating achieved the same corrosion resistance as stainless steels (264 h test time) and can be used in technical practice.