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15 results on '"Václavková, Šárka"'

1. The Difficulties of Designing Technical-Economic Models for Czech Wastewater Treatment Plants

Author

Zejda, Vojtěch, Gregor, Jiří, Kropáč, Jiří, Václavková, Šárka, Zejda, Vojtěch, Gregor, Jiří, Kropáč, Jiří, and Václavková, Šárka

Abstract

This paper describes the main points that must be faced when preparing a methodology for a techno-economic model of a wastewater treatment plant (WWTP). The model and the design are meant to be applied to real WWTP technologies in the Czech Republic. Most of Czech WWTPs combine mechanical and biological processes to treat wastewater. The main waste product of all wastewater treatment processes is sewage sludge (SS), which is typically a semiliquid mixture of organic and inorganic substances. The paper summarises the basic research on the WWTP models, presents the basic structure of the techno-economic model and describes the basic input data sets, which are crucial for the analysis of real WWTPs. The aim is to propose the structure and design of a techno-economic model that will be sufficiently variable and can evaluate the mechanical equipment of the WWTP together with the variable composition of wastewater.

Published
2020

4. Resolving Discrepancies in Reported Flow Amounts in Sewage Sludge Management Network Datasets by Mathematical Programming.

Author

Václavková, Šárka, Pluskal, Jaroslav, Šomplák, Radovan, Talpa, Jaroslav, and Smejkalová, Veronika

Subjects
SEWAGE sludge, WASTE management, LOGISTICS, MATHEMATICAL programming, DATA analysis
Abstract

For further development and infrastructure planning, considerations regarding economically feasible, efficient and appropriate waste management are essential. In current waste management networks and related datasets, errors and discrepancies arise in the reported values, to due to an insufficient detail of used infrastructure, which is often reduced to only several nodes in the case of very complex tasks. This paper presents an optimised multi-criteria mathematical programming model, which enables to obtain data for more detailed infrastructure while preserving the efficiency of the calculation using mathematical modifications and algorithms. The paper describes the method of how to divide the estimated flows in a chosen area among different sources. The optimized robust model minimizes the total sum of absolute deviations from the original data. It also considers logistics in the form of distances and emulates the economic behaviour of subjects in the network. The alternating direction method of multipliers is applied for an original model solution, together with a heuristic used for one set of ambiguous variables. This algorithm facilitates the solving of large instances of the defined problem. The implementation of the algorithm and all computations are done in the Julia programming language involving specialized optimisation libraries. The functionality of the optimised model is shown on the sewage sludge management network dataset of the Czech Republic, which contains approximately 200 entities. Such a dataset leads to the model with approximately 400,000 of decision variables. The results of the presented case study are used for the improvement of the treatment of sludge, a waste produced in wastewater treatment plants. The proposed model is general enough as it can be also used for estimating real waste flow datasets containing a similar type of error as described. [ABSTRACT FROM AUTHOR]

Published
2020
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10. Materiálové a energetické využití suchého stabilizovaného čistírenského kalu - výroba biocharu středně-teplotní pomalou pyrolýzou.

Author

POHOŘELÝ, Michael, MOŠKO, Jaroslav, ZACH, Boleslav, ŠYC, Michal, VÁCLAVKOVÁ, Šárka, JEREMIÁŠ, Michal, SVOBODA, Karel, SKOBLIA, Siarhei, BEŇO, Zdeněk, BRYNDA, Jiří, TRAKAL, Lukáš, STRAKA, Pavel, BIČÁKOVÁ, Olga, and INNEMANOVÁ, Petra

Abstract

Copyright of Waste Forum is the property of Czech Environment Management Center (CEMC) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2017

12. Fluidized Bed Incineration of Sewage Sludge in O2/N2and O2/CO2Atmospheres

Author

Moško, Jaroslav, Pohořelý, Michael, Zach, Boleslav, Svoboda, Karel, Durda, Tomáš, Jeremiáš, Michal, Šyc, Michal, Václavková, Šárka, Skoblia, Siarhei, Beňo, Zdeněk, and Brynda, Jiří

Abstract

Sewage sludge incineration in a fluidized bed is considered to be one of the most suitable ways of sewage sludge disposal. This process reduces the volume of the waste and causes the destruction of organic contaminants such as POPs, pharmaceuticals, and other compounds with endocrine-disrupting potential. Oxygen-enriched air combustion and oxy–fuel combustion can increase the combustion efficiency, reduce the amount of flue gas, and make possible CO2capture more effective. However, the influence of incineration medium composition has not yet been thoroughly investigated in the case of sewage sludge incineration. In this paper, the incineration of sewage sludge in a bubbling fluidized bed reactor was studied at oxygen-enriched air conditions, oxy–fuel conditions, and oxy–fuel conditions with zero and nonzero concentrations of steam, CO, NO, N2O, and SO2in the inlet combustion medium. Consequently, the effects of various operating parameters on pollutants formation were comprehensively described with emphasis on aforementioned sewage sludge incineration processes. An increase in combustion temperature resulted in an increase in NOxand SO2emissions and in a decrease in N2O emissions. Increase in inlet oxygen concentration led to a decrease in NOxand N2O emissions. N2O and SO2emissions were higher in CO2-rich atmosphere (oxy–fuel combustion conditions). The presence of water vapor in the inlet combustion medium resulted mainly in the reduction of NOxemissions. The presence of CO, NO, N2O, and SO2in the dry inlet combustion medium reduced mainly overall nitrogen-to-NOxconversion, while the effect on SO2removal efficiency was only marginal.

Published
2018
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13. Materiálové a energetické využití suchého stabilizovaného čistírenského kalu

Author

Pohořelý, Michael, Moško, Jaroslav, Šyc, Michal, Václavková, Šárka, Skoblia, S., Beňo, Z., and Svoboda, Karel

Subjects
pyrolysis, sewage sludge, fluidized bed combustion, fertilizer, fluid combustion, ash
Abstract

The paper describes the need for change in the way of sewage sludge disposal in the Czech Republic. The main reason for the change is the amendment to the current Czech and European legislation.

Published
2019

14. Use of Sodium Bicarbonate for Flue Gas Treatment in Small Scale

Author

Zach, Boleslav, Pohořelý, Michael, Šyc, Michal, Svoboda, Karel, Václavková, Šárka, Moško, Jaroslav, Brynda, Jiří, and Punčochář, Miroslav

Subjects
flue gas treatment, sodium bicarbonate, dry sorption
Abstract

The trend of reduction of landfilling can lead, especially in areas with low population density, to the need to build new waste-to-energy capacities in the form of small units. However, flue gas treatment in small scale has to be sufficiently simple to decrease capital costs and allow the construction of such facilities. For that reason, the possibility of one-step dry flue gas treatment at compromise conditions was investigated as well as the limitation of flue gas composition.\n\n

Published
2019

15. Properties of Biochar Produced by Slow Pyrolysis of Stabilized Sewage Sludge

Author

Moško, Jaroslav, Pohořelý, Michael, Skoblia, S., Beňo, Z., Brynda, Jiří, Zach, Boleslav, Šyc, Michal, Václavková, Šárka, Jeremiáš, Michal, and Svoboda, Karel

Subjects
pyrolysis, sewage sludge, biochar
Abstract

Direct application of stabilized sewage sludge on agricultural soil is currently a big concern because of its significant content of detectable organic micropollutants. Proper sludge treatment should suppress its negative features and produce material suitable for soil amendment. Slow pyrolysis is one of such treatments. We studied the influence of pyrolysis temperature (400-800 °C) on material and energy balances and on elementary composition of the pyrolysis solid residue (biochar). Pyrolysis at higher temperatures resulted in lesser biochar yield and promoted gas yield. The macronutrient content of biochar increased with an increase in pyrolysis temperature (except for nitrogen).

Published
2017

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