This work is focused on verification of p-Nitrotoluenu toxicity and compounds resulting from the aerobic transformation, and methyl group oxidation and reduction of nitro. Some of these products are not commercially available and had to be made soon. Toxicity of the substances was determined by toxicity tests. Were tested root growth inhibition Sinapis alba, which resulted in an inhibitory concentration IC50; test inhibition duckweed Lemna minor , which was also the determination of IC50 inhibitory concentration, and acute toxicity test Artemia salina, which was observed in mortality and immobility organisms and the test result was an efficient concentration EC50 value. Results of tests are compared in the conclusion of the work and is made evaluation of the toxicity of individual substances.

Benzene is very toxic compound, which has carcinogenic and mutagenic effects. Result of these effects is significant reduction of its use and also low hygienic limits in occupational environment and environment. The aim of this diploma thesis was to map out possible exposure to benzene and checking of clasification correctness of motor gasoline and benzine (cleaners, thinners etc.). Determination of benzene was carried out by gas chromatography with flame ionisation detector (GC/FID) and high performance liquid chromatography with diod array detector (HPLC/DAD). Marginally, the diploma thesis was focused on determination of toluene (in june 2007 became effective ordinance no.284/2006 Sb., which forbid to sell products that contain more than 0,1 % of toluene to small consumers). Toluene was determined by same methods as benzene.

<p>U ovom radu kori&scaron;cen je spektroskopski, teorijski i hemometrijski pristup<br />proucavanju N-HO i N-H&middot;&middot;&middot; vodonicne veze koja se uspostavlja izmedu<br />amidnog protona i etarskog kiseonika tj aromaticnog sistema. U ovom radu<br />odredeni su parametri N-HO i N-H vodonicne veze za &scaron;esnaest Nsupstituisanih<br />amida sa tetrahidrofuranom i toluenom. Vecina ispitivanih amida do<br />sada nije bila izucavana sa stanovi&scaron;ta vodonicne veze. Uspostavljene su korelacije<br />izmedu spektorsopskih i teorijskih parametara. Izvr&scaron;eno je poredenje medu<br />osobinama vodonicno vezanih kompleksa za razlicite amide kao proton donore.<br />Svih 32 ispitivanih vodonicno vezanih kompleksa okarakterisano je<br />hemometrijskim metodama: Klaster analizom i analizom glavne komponente, na<br />osnovu spektroskopskih, teorijskih i Taftovih parametara</p> / <p> In this PhD thesis, N-H&times;&times;&times;O and N-H&middot;&middot;&middot; hydrogen bond beetwen the amide<br /> proton with ether oxygen and aromatic system has been investigated using the<br /> spectroscopic and theoretical approach. The study included sixteen N-substituted<br /> amides (formamides, acetamides, caproamides and benzamides) as well as<br /> tetrahydrofuran and toluene. The possibility of using chemometric methods was<br /> investigated in order to characterise N-H...O and N-H&middot;&middot;&middot; hydrgen bonded<br /> complexes. Hierarchial clustering and Principal Component Analysis (PCA) have<br /> been applied on infrared spectroscopic, PM3 theoretical and Taft parameters of 32 Nsubstituted<br /> amide complexes with tetrahydrofuran and toluene</p>

This diploma thesis has been carried out as a part of the project Utilization of long term (passive) sampling methods combined with in situ microcosms for assessment of (bio)degradation potential (PASSES). In the frame of the project groundwater remediation took place in the premises of Farmak a.s. in Olomouc using a pilot photooxidation unit and efficiency of the remediation was monitored through passive and active sampling methods. Pilot photooxidation unit is a technology based on the H2O2/UV-C photochemical oxidation of organic pollutants. In this work optimization tests of the pilot photooxidation unit were performed. The residence time of the groundwater in the photoreactors, required for its sufficient decontamination from pharmaceuticals and aromatic hydrocarbons, was 2.5 hours. 91% degradation of the pharmaceuticals and 80% degradation of aromatic hydrocarbons were reached during this interval. Although the removal efficiency of the pharmaceuticals by the photooxidation unit was high, the pilot photooxidation unit was not able to effectively remove the pharmaceuticals at the studied locality. By comparing the results of the pharmaceuticals from active and passive groundwater sampling during the remediation attempt, passive Polar Organic Chemical Integrative Sampler (POCIS) was found to be...

The proton exchange membrane fuel cell generates electricity from hydrogen and oxygen (from air) through electrocatalytic reactions in an electrochemical cell. The Pt/C catalyst, commonly used in PEM fuel cells, is very sensitive to impurities that can interact with the active catalyst sites and limit fuel cell performance. Unfortunately, most hydrogen is currently produced from fossil sources, and inevitably contains impurities. The subject of this thesis is the effect of hydrogen impurities on the operation of a PEM fuel cell using a Pt/C anode. The impurities studied are carbon monoxide (CO), carbon dioxide (CO2), and selected hydrocarbons. Particular focus is given to the interaction between the impurities studied and the anode catalyst. The main method used in the study involved performing cyclic voltammetry and mass spectrometry, simultaneously. Other electrochemical techniques are also employed. The results show that all the impurities studied adsorb to some extent on the Pt/C catalyst surface, and require potentials comparable to that of CO oxidation, i.e., about 0.6V, or higher to be removed by oxidation to CO2. For complete oxidation of propene, and toluene, potentials of above 0.8, and 1.0V, respectively, are required. The unsaturated hydrocarbons can be desorbed to some extent by reduction, but oxidation is required for complete removal. Adsorption of ethene, propene, and CO2 is dependent on the presence of adsorbed or gaseous hydrogen. Hydrogen inhibits ethene and propene adsorption, but facilitates CO2 adsorption. Adsorption of methane and propane is very limited and high concentrations of methane cause dilution effects only. The adlayer formed on the Pt/C anode catalyst in the presence of CO2, or moderate amounts of hydrocarbons, is found to be insffuciently complete to notably interfere with the hydrogen oxidation reaction. Higher concentrations of toluene do, however, limit the reaction. / Polymerelektrolytbränslecellen genererar elektricitet fran vätgas och syrgas (fran luft) genom elektrokatalytiska reaktioner i en elektrokemisk cell. Den platina-baserade katalysator som oftast används i dessa bränsleceller är känslig mot föroreningar, då dessa kan interagera med katalysatorns aktiva yta, och därmed begränsna bränslecellens prestanda. Tyvärr produceras dagens vätgas huvudsakligen fran fossila källor och innehåller därför oundvikligen föroreningar. Denna avhandling behandlar hur olika vätgasföroreningar påverkar katalysatorns aktivitet och bränslecellens drift. De föroreningar som studeras är kolmonoxid (CO) och koldioxid (CO2), samt ett antal mindre kolväten. Störst fokus ligger på hur dessa föroreningar interagerar med anodens Pt/C katalysator. Den metod som huvudsakligen används är cyklisk voltammetri kombinerat med masspektrometri, men flera elektrokemiska metoder har använts. Resultaten visar att alla undersökta föroreningar adsorberar på Pt/C katalysatorns yta i större eller mindre utstreckning. For att avlägsna det adsoberade skiktet genom oxidation till CO2 krävs potentialer jämförbara med CO oxidation, dvs ca 0,6V, eller högre. Fullständig oxidation av propen eller toluen kräver potentialer högre än 0,8V respektive 1,0V. De omättade kolvätena kan delvis avlägsnas genom reduktion, men fullständig avlägsning kräver oxidation. Närvaron av väte, i gasform eller adsorberat pa katalysatorn, hämmar adsorptionen av eten och propen, men främjar CO2 adsorption. Metan och propan adsorberar i mycket begränsad utstreckning på Pt/C katalysatorns yta. De prestandaförluster som uppstår av höga koncentrationer av metan förklaras av utspädning av vätgasen. Det adsorberade skiktet som bildas när Pt/C katalysatorn exponeras för CO2 eller måttliga koncentrationer av studerade kolväten, är inte tillräckligt heltäckande for att märkbart påverka vätgasreduktionen. Däremot kan höga koncentrationer av toluen begränsa reaktionen. / <p>QC 20161010</p>

En av de vanligaste föroreningarna i mark och grundvatten är aromatiska kolvä- ten såsom bensen, toluen, etylbensen och xylener. Dessa härstammar från ex. ben- sin och har läckt ut till omgivande miljö från drivmedelsanläggningar. I stället för schaktning och bortforsling av de förorenade jordmassorna som mest förekom- mande ex situ-saneringsmetod behövs mer forskning kring in situ-saneringsmetoder där föroreningen alltså kan angripas på plats. I denna rapport undersöks förhöjd biologisk nedbrytning genom att redogöra för de önskvärda (bio)kemiska reak- tionerna i marken, de parametrar som styr den biologiska nedbrytningen samt huruvida dessa parametrars inverkan har kunnat påvisas i tre stycken fallstu- dier där in situ-sanering utförts vid drivmedelsanläggningar. Studien kommer fram till ett antal primära (ursprungliga) variabler såsom föroreningen i fråga, jordtätheten och klimatet, samt ett antal sekundära (förändringsbara) variabler såsom oxidationsmedlet, mikroorganismerna, näringsämnena och markvattnet. Dessa presenterades sedan i en schematisk skiss som visar hur de växelverkar med parametrarna för optimal biologisk nedbrytning, vilka visade sig ha vissa optimala värden. Dessa konstaterades vara föroreningshalten (&lt;5-10 viktprocent torr jord), pH-värdet (6-9), temperaturen (20-35◦C), vattenmättnaden (40-80%), syrehalten (&gt; 2 500 viktprocent kolväten), C:N:P-kvoten (100:10:1) samt koncent- rationen mikroorganismer (&gt; 103 CFU/ml). När de olika parametrarnas inverkan  i fallstudierna undersöktes kunde slutsatsen dras att det skulle behövas ytterliga- re data och mätningar vid varje sanering för att kunna garantera att parametrarna varit inom sina respektive optimala värden. / One of the many goals for a sustainable living and a healthy environment is the reduction of toxic substances in soil and groundwater. Within this ambit, one of the most common pollutants is aromatic hydrocarbons such as benzene, tolue- ne, ethylbenzene and xylenes (BTEX) which are spread from e.g. filling stations for fuel as they are constituents of petrol. These are volatile and can constitute a risk for humans and the environment as they percolate through the soil and groundwater resources as well as can exfiltrate from the ground to surrounding buildings and pollute the indoor air. Once these pollutants are present in the soil, the site needs to be remediated, something which is mainly done ex situ by exca- vating the polluted masses to be sent to a treatment facility. An alternative to this is in situ remediation where the pollution can be treated without being excavated and thus having a smaller impact on the environment.  In this report, one of these techniques called enhanced biodegradation was studied, which implies the application of oxidisers to faciliate microbial activities. It investigated (1) how this remediation technique works and what (bio)chemical reactions are desired in the soil; (2) what are the principal parameters that enable this remediation process and how do they interact with the surrounding factors, and (3) whether the impact of these parameters can be estimated in three case studies where this technique has been used. The three case studies were filling stations located in Sweden, having similar pollutants and geology, and two diffe- rent oxidisers had been used.  The study resulted in the identification of a number of primary (initial) varia- bles such as the pollutant characteristics, the soil density and the climate; as well as a number of secodnary (modifiable) variables such as the oxidiser, microorga- nisms, nutrients and soil moisture. These were then presented in a scheme which shows how their interactions with the parameters for optimal biodegradation. Each parameter was found to have a certain optimum such as the concentration of hydrocarbons (&lt;5-10 mass percent of the dry soil) , pH value (6-9), tempe- rature (20-35◦C), soil water saturation (40-80%), oxygen concentration (&gt; 2,500 mass percent of the hydrocarbons), C:N:P ratio (100:10:1) as well as concentration of microorganisms (&gt; 103 CFU/ml). A negative correlation could be identified between the soil density and the oxygen concentration in the soil, as well as a po- sitive correlation between the soil water saturation in the and the soil moisture, alternatively additional water via irrigation. The impact of each parameter in the case studies of in situ remediation was assessed and the it could be concluded that they would need additional data and measurements for most parameters in order to guarantee that they are within the respective optima.