|
|
Risk element sorption on waste materials from olive oil production
Hovorka, Miloš ; Száková, Jiřina (advisor) ; Trakal, Lukáš (referee)
The main objective of this thesis is to verify the efficiency of waste material from olive oil production to immobilize risk elements Pb, Cd and Zn in extremely contaminated soil and to verify following hypothesis: application of waste material from olive oil production will limit the availability of risk elements in the soil and also improves a supply of soil available nutrients and biological properties of the soil. The work is divided into two parts, theoretical part (literature review) and experimental part.
The theoretical part contains a general description of the risk elements and their possible harmful effects on living organisms, indicating their possible sources of entry into the environment, describes the behavior of these elements in the soil, especially events that contributes to the retention of soil. Furthermore, there are some possible methods for remediation of soil contaminated with hazardous elements and is described in more detail immobilization technique using soil improvers. In this chapter is devoted to the waste material from olive oil production, whose properties are tested in the experimental part of this work.
The experimental part is focused on verification sorption capability of waste material from olive oil production for selected risk elements. As a waste material has been used dry olive residue (known as DOR), and DOR after remediation of these types of fungi: Penicillium chrysogenum, Coriolopsis floccosa, Bjerkandela adusta and Chondrostereum purpureum. Analytical methods were used to determine the concentrations of the elements, the pH, the point of zero charge (pHpzc), and cation exchange capacity (CEC) for the individual samples representing material DOR and DOR after remediation of certain species of fungi. The preliminary sorption experiment determined sorption efficiency for the elements Cd, Pb and Zn for all the material tested. Stability of the risk element bonds was verified via model desorption experiment. Model laboratory incubation experiment was carried out to assess the potential changes of hazardous elements mobility in the contaminated soil, depending on dose and type of DOR material. At the same time there were determined contents of available proportions of essential elements in the soil. The contents of elements were determined by atomic spectrometry (ICP-OES) and the results analyzed by adequate statistical methods.
Results showed good sorption capacity of the waste material DOR, especially after transformation with different species of fungi, for hazardous elements and particularly Pb, less then Cd and Zn. The desorption experiment, however, showed unstable linkages elements in samples DOR, particularly in the case of Zn, which is also reflected in the incubation experiment. This instability is probably due to the low pH material DOR, therefore it would be useful for further research take into account the increase of pH levels of these samples. In terms of elemental composition appears to be biotransformed DOR as a good source of nutrients. The treatment of thesoil increased accessibility of nutrients such as Cu, Fe and Mn for plants.
|
|
| |
|
| |
|
|
Scanning Very Low Energy Electron Microscopy
Müllerová, Ilona ; Hovorka, Miloš ; Mikmeková, Šárka ; Pokorná, Zuzana ; Mikmeková, Eliška ; Frank, Luděk
Recent developments in applications of the scanning very low energy electron microscopy in selected branches of materials science are reviewed. The examples include visualization of grains in conductive polycrystals including ultrafine grained metals, identification of the local crystal orientation upon reflectance of very slow electrons, transmission mode with ultrathin free-standing films including graphene, acquisition of a quantitative dopant contrast in semiconductors, and examination of thin surface coverages.
|
|
| |
|
| |
|
| |
|
| |
|
| |
|
|
Transmission mode in scanning low enery electron microscope
Müllerová, Ilona ; Hovorka, Miloš ; Frank, Luděk
We incorporated the cathode lens (CL) principle, well known from the emission microscope, to the SEM in order to operate at very low landing energies. The primary beam electrons of several keV are decelerated to nearly zero energy of landing on the specimen negatively biased to high potential. Reflected electrons are collected on a grounded detector situated above the sample but the same can be done below the sample of a fair transparency for electrons. High collection efficiency and high amplification of both detectors is secured thanks to the cathode lens field. We use a scintillation detector for the reflected mode and a semiconductor structure for the transmitted electron (TE) mode. In this arrangement resolution of few nm is obtainable across the full energy range.
|
guest ::
RSS feed.