|
Methods of sewage sludge treatment for agricultural applications with respect to micropollutants
Vítková, M. ; Komárek, M. ; Wickramasinghe, N. ; Pohořelý, Michael ; Moško, Jaroslav ; Hušek, Matěj ; Cajthaml, Tomáš ; Grasserová, Alena ; Čechmánková, J. ; Vácha, R. ; Zimová, M.
The aim of the methodology is to describe the possibilities of sewage sludge treatment by composting and pyrolysis for the application in agriculture, with particular respect to the so-called micropollutants, but also to conventional pollutants, and to assess the risks of treated sludge for the soil environment and the uptake of (micro)pollutants by cultivated crops. The methodology is based on the results from laboratory and field experiments of a three-year project and on a critical approach to sludge as a potentially hazardous waste on the one hand and a recyclable source of nutrients on the other.
|
| |
| |
|
Comparison of properties of biochars based on different types of sewage sludge.
Moško, Jaroslav ; Beňo, Z. ; Hušek, Matěj ; Komárek, M. ; Vítková, M. ; Pohořelý, Michael
The application of sewage sludge to agricultural land is an increasingly debated topic, particularly because of the precautionary principle regarding the content of inorganic, organic and microbial pollutants. One of the practices treatment/treatment of sludge prior to land application is pyrolysis, whereby \nbiochars are produced from the sewage sludge, which, provided that proper process management, stable and free from organic and microbial \ncontamination. The aim of this paper was to verify the properties of biochars from sewage sludge that were subjected to different types of stabilization. The sludges were pyrolyzed at temperatures ranging from 600 to 650 °C and a certain correlation was found between degree of sludge stabilization and biochar properties (textural properties, elemental composition, energy value). \n\n
Plný tet: PDF
|
| |
| |
|
Influence of sorbent type on dehalogenation of reducing gas without condensing fraction.
Šrámek, Vít ; Skoblia, S. ; Staf, M. ; Beňo, Z. ; Pohořelý, Michael
Chemical recycling of plastics is one of possible option to process large amount of currently difficultly recycled plastic waste. It would be possible to fulfil goals of the amount of recycled waste by means of chemical recycling. Principle of chemical recycling is conversion of plastic waste to basic hydrocarbon substance that could be used in refineries or petrochemical industry. The main technological challenge is the presence of halogens in plastic waste (in plastics as substances containing chlorine in form of PVC or brome in form of additives/flame retardants). During chemical recycling via pyrolysis, these substances can transfer to products and cause problems in succeeding technologies (corrosion, poisoning of catalysts etc.). One of the solutions how to eliminate these unwanted substances could be high temperature sorption of primal pyrolysis gas on sorbents before its condensation. Experiments with model gas containing halogenated compounds and different inorganic sorbents were conducted for this purpose. Gained results allowed us to narrow down the amount of sorbents suitable for high temperature removal of halogenated compounds from primal pyrolysis gas produced during pyrolysis of plastics.
Plný tet: PDF
|
| |
| |
|
Utilization of waste from processing of industrial hemp for production of carbonaceous adsorbents.
Šrámek, V. ; Staf, M. ; Pohořelý, Michael ; Beňo, Z.
Utilization of waste biomass for production of carbonaceous adsorbents would be a suitable substitution of comercially available activated carbon. This work focuses on a two step preparation in two separate apparatus of own construction operated at UCT Prague. The first step involves pyrolysis of the hemp hurd at temperature range 450–850 °C and the second step is based on activation of the pyrolysis residue via steam at temperatures 740 and 800 °C. The prepared activated material was examined for key sorption parameters: specific surface are by BET equation, total specific pore volume and pore size distribution. The results were compared to comercially available activated carbon produced also via the steam activation.
Fulltext: content.csg - PDF Plný tet: SKMBT_C22020012013491 - PDF
|