National Repository of Grey Literature 117 records found  beginprevious81 - 90nextend  jump to record: Search took 0.00 seconds. 
Diversity of bees on selected crops and their contamination by pesticides
HÝBL, Marian
Measurement of diversity and chemical contamination of bees took place at two locations. At the Zborov site, conventionally growing rape and Malonty, where it is managed in an ecological regime. At the Zborov locality, 81 individuals from 3 families, including 20 species, were captured. In addition, analyzes have confirmed the presence of pesticides in bees. In contrast, 229 individuals from 5 families, including 36 rings, were seized at Malonty. Analysis of bees in this area has rebutted the presence of pesticides.
Determination of selected pesticides and their metabolites by LC/MS
Kořínková, Petra ; Tesařová, Eva (advisor) ; Trešl, Ivan (referee)
Pesticides are the substances designed for destroying, preventing and controlling of pests and protection of plants. Their wide usage in agriculture causes contamination of ground, surface and drinking water, because wastewater treatment plants are not able to remove them. Mostly used pesticides are triazine based pesticides. However their usage is worldwide reduced because of their negative influences on human health and contamination of environment especially with their metabolites, about their toxicity are no information. A method for determination of triazine pesticides atrazine, cyanazine, propazine, simazine, terbuthylazine and their metabolites hydroxytrazine, desethylatrazine, desisopropylatrazine, hydroxyterbuthylazine a desethylterbuthylazine was developed and validated in this diploma work. The determination was realized by LC-MS/MS with electrospray ionization. LOD ranged between 0.5-3.2 pg/ml and LOQ between 1.5-9.6 pg/ml. A test of stability of the maternal substances of these pesticides was performed, in which temperature was found to have the biggest influence on their degradation. A monitoring of the presence of triazine pesticides and their metabolites in water was carried out in Czech Republic. Low concentrations of the maternal substances in surface water and ground water were...
Adsorption of pesticides onto granular activated carbon in water treatment process
Kopecká, Ivana ; Hnaťuková, Petra (advisor) ; Pivokonský, Martin (referee)
The diploma thesis is aimed at adsorption processes during the removal of pesticides onto granular activated carbon (GAC) in the process of drinking water treatment. Adsorption onto GAC represents an efficient method for pesticides removal. High adsorption efficiency can be significantly reduced due to the occurrence of natural organic matter (NOM) in raw water, which involves AOM (Algal Organic Matter) produced by phytoplankton. Analogous to NOM, AOM probably affects adsorption of pesticides by two different mechanisms - a direct site competition and pore blockage effect, in dependence on the different molecular weight of particular AOM fractions. Equilibrium batch and kinetic adsorption experiments were performed using two types of GAC (Norit 1240 and Filtrasorb 400) and two pesticides (terbuthylazine and alachlor). In order to examine the effect of AOM on adsorption of pesticides, raw GAC and GAC preloaded by AOM were used. The effect of pH on the competitive adsorption of AOM was also evaluated. A solid phase extraction (SPE) method and gas chromatography with electron capture detection (GC-ECD) were used to determine pesticides in water samples. AOM was characterized using fractionation onto sorptive resins. The representation of apparent molecular weights of AOM proteins was determined by...
Determination of pesticides enantiomers in water
Šlechtová, Tereza ; Lokajová, Jana (referee) ; Tesařová, Eva (advisor)
This Barchelor's project deals with chiral herbicide mecoprop and its determination by high-performance liquid chromatography method with teicoplanin based chiral stationary phase. The teoretical part focus on basic facts conserning chirality, chiral pesticides and problems related to their usage and effects to the enviroment. It also involves the ways of their determination by the above mentioned method and gives several examples of previous separations. The experimental part is based on method optimalization and determination of changes in mecoprop enantiomeric ratio in various water samples during different storage conditions.
Monitoring of pesticides in source of water treatment Hrdibořice and possibility of their removal
Bouchalová, Zuzana ; Svoboda,, Miroslav (referee) ; Biela, Renata (advisor)
The thesis discusses possible ways to reduce or completely eliminate pesticide compounds from drinking water that are produced at a water treatment plant Hrdibořice. The work is divided into theoretical and practical parts. The theoretical part lists kinds of pesticides that occur in water, how they are reduced or eliminated. Furthermore, this section describes the existing water treatment technologies at the Central Committee Hrdibořice, including water sources. In the practical part, pilot tests on two types of filters models with filtering bed of granular activated carbon (hereinafter GAU) were carried out. On the basis of information obtained from the literature and on findings from the pilot tests, designs of technological equipment for pesticide removal from drinking water at water treatment Hrdiborice were carried out. Next, cost estimates for the proposed variant solutions including operating costs were suggested.
The Use of Separation Methods for the Study of Selected Drugs and Pesticides in Water
Burešová, Jitka ; Hajšlová, Jana (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Vávrová, Milada (advisor)
This work is focused on the study of penetration of pesticides and pharmaceuticals in the aquatic environment. The aim was to develop and verify the optimal method for long-term monitoring of the occurrence of selected pesticides and pharmaceuticals in surface waters. Two frequently used analgesics ibuprofen and diclofenac, and carbamazepine that is used to treat epilepsy, were chosen from the group of drugs. A group of 41 pesticides were selected for monitoring too. The attention was focused on a group of urea pesticides and phenoxyacetic acids, as well as on selected pesticides falling to the group of priority substances or identified as environmental quality standards. Some of pesticides were selected because their consumption in the Czech Republic exceeds 30 tons a year. Liquid chromatography with tandem mass spectrometry (LC / MS / MS) was used for the determination of selected analytes in surface waters. Two optimized analytical method were developed. Ten analytes were determined in negative ion mode and 34 analytes in positive ion mode. Solid phase extraction (SPE) was used for purification and concentration of the samples. Developed methodology was validated and used for monitoring of selected compounds in samples of surface waters from the Morava River basin. Samples were collected on the rivers Morava and Svratka monthly for two years. Samples from the river Blata and stream Nivnička were collected for one year. Surface water samples were also collected from the river Litava. Four samples were taken throughout the length of the flow during one day. Smaller streams were chosen for monitoring because of the probability of occurrence of pesticides. They flow abundantly agriculturally cultivated areas. Drugs ibuprofen and diclofenac were detected in all taken samples, carbamazepine mostly. Among the most commonly occurring pesticides were bentazon, diuron, isoproturon, carbendazim, MCPA, MCPP, propiconazole, tebuconazole and 2,4-D.
Ecotoxicity of selected pesticides
Konečná, Veronika ; Vávrová, Milada (referee) ; Zlámalová Gargošová, Helena (advisor)
Presented diploma thesis is focused on the ecotoxicological evaluation of insecticide mixtures Perfekthion and Bulldock 25 EC and their effective substances, dimethoate and beta-cyfluthrin, respectively. Dimethoate is an organophosphate insecticide while beta-cyfluthrin belongs to pyrethroids. Both mixtures’ target organisms are sucking and biting pests on grain crops, potatoes, vegetables, oilseed rape and ornamental flowers. Their application over large areas and transport in large volumes generates a significant risk of entering the environment. Mixtures and substances were tested on water plant Lemna minor, algae Desmodesmus quadricauda and crustaceans Daphnia magna and Thamnocephalus platyurus. The LC50, EC50, and IC50 values were determined and ecotoxicity of substances and mixtures was evaluated and compared.
Study of xenobiotics and biologically active compounds degradation on titanium dioxide
Píšťková, Veronika ; Lisá,, Hana (referee) ; Vávrová, Milada (advisor)
Heterogenous photocatalysis using titanium dioxide seems to be a promising method for disposal xenobiotics from the environment. The aim of this diploma thesis is the study of degradation of selected xenobiotics and biologically active substrances applying this method. Theoretical part of diploma thesis deals with the principals of heterogenous photocatalysis by means of a semiconductor TiO2 and the examples of its possible application are mentioned too. The compounds which could be appropriate for a study of degradation were selected from the group of pharmaceuticals and pesticides. The properties of target substances and their environmental impact were described. Furthermore, a bibliographic search focused on the possibilities of their analytical determination was conducted. The experimental part of the thesis describes the experiments with photocatalyst in a form of powder as well as with immobilized photocatalyst in thin layer on a carrier. Identification and quantification of analytes was realized by high performance liquid chromatography with mass spectrometic detection.
Using of organism Eisenia foetida in ecotoxicity tests
Modlitbová, Pavlína ; Vávrová, Milada (referee) ; Zlámalová Gargošová, Helena (advisor)
Pesticide products used for plant protection are one of the chemicals that are intentionally brought into the environment. In Czech Republic there are legally used only those pesticide products, which are registered by SRS (State Phytosanitary Administration). For registration of these products there is required in addition to assessing the likely negative effects on human and animal health, also information whether the pesticide products negatively not affect the environment, in particular avoiding the contamination of aqua system or not effect the non target organisms. This master's thesis discuss the use of organism Eisenia foetida (redworm) in the contact ecotoxicity tests by testing pesticide products. There were selected such pesticide products where there are not solid information about their impact on non-target soil organism (Eisenia foetida) and based on literature research was chosen ecotoxicity test by OECD 207 method, the acute toxicity test which is in place for 14 days. Two pesticide products Topsin M 500 SC (active ingredient thiophanate-methyl) and Perfekthion (active ingredient dimethoate) were tested. Ecotoxicological values were calculated and ecotoxicity of such peticide products for soil organism were avaulated.
The application of pollen as bioindicator of the environmental state
Marečková, Kateřina ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Pesticides and their excessive use lead to environmental pollution. Violation of the guidelines for their use disposal of empty containers could lead to contamination of water, soil and poisoning of animals and beneficial insects. Honey bee is useful creature on our planet. Good farming depends entirely on the pollination, but whole vegetal kingdom couldn’t exist it form known and used by mankind. Therefore, rules that protect these useful creatures against inadequate use of pesticides have been developed. This study focuses on the evaluation of the possibility to use bee products as bioindicators of the state of environment. Five active substances which are components of pesticides used in the treatment of agricultural field around Tasovice village were analysed in the pollen and honey. For sample preparation QuEChERS and SPE methods were used, gas chromatography with to mass spectrometric detection was employed as final analytical technique.

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