Maroš Sirotiak

Occurrence of selected organochlorine pesticide residues in surface sediments from the Velke Kozmalovce, Ruzin, and Zemplinska Sirava water reservoirs, Slovakia

Occurrence of selected organochlorine pesticide residues in surface sediments from the Velke Kozmalovce, Ruzin, and Zemplinska Sirava water reservoirs, Slovakia Surface sediment samples from three water reservoirs of Slovakia were analyzed for selected organochlorine pesticides (OCPs). Concentrations of total dichlorodiphenyltrichloroethanes (ΣDDTs) in the sediments from Velke Kozmalovce, Ruzin, and Zemplinska Sirava ranged from 12 to 24 ng g-1, 5 to 28 ng g-1, and 1 to 20 ng g-1, respectively, with the exception of one sediment sample from Zemplinska Sirava, having anomalously high concentration of ΣDDTs (526 ng g-1). Concentrations of hexachlorobenzene (HCB) in the sediments from these water reservoirs were generally lower and ranged from 0.3 to 9 ng g-1. Other organochlorine pesticides such as mirex, lindane and heptachlor were not detected in the surface sediments. Ratios of DDT/(DDE + DDD) were lower than 1.0 in majority of the sediment samples indicating that the degradation of the parent DDT occurred significantly and DDT in the sediments from the studied water reservoirs was derived mainly from the weathered agricultural soils. Moreover, ratios of DDD/DDE indicated that the parent DDT was degraded under aerobic conditions before depositing into the sediments of these water reservoirs. Výskyt rezíduí vybraných organochlórovaných pesticídov v sedimentoch z vodných nádrží Veľké Kozmálovce, Ružín a Zemplínska Šírava, Slovensko V štúdii boli analyzované vzorky sedimentov z troch vodných nádrží Slovenska na vybrané organochlórované pesticídy (OCPs). Koncentrácie sumy DDT a jeho metabolitov DDE a DDD (ΣDDTs) v sedimentoch z vodných nádrží Veľké Kozmálovce, Ružín a Zemplínska Šírava sa nachádzali v intervale od 12 do 24 ng g-1, od 5 do 28 ng g-1 a od 1 do 20 ng g-1, s výnimkou jednej vzorky sedimentu zo Zemplínskej Šíravy, ktorá vykazovala anomálne vysokú koncentráciu ΣDDTs (526 ng g-1). Koncentrácie hexachlórbenzénu (HCB) v sedimentoch z týchto vodných nádrží boli všeobecne nižšie a pohybovali sa v intervale od 0,3 do 9 ng g-1. Iné v sedimentoch sledované organochlórované pesticídy ako mirex, lindán a heptachlór neboli zistené. Vo väčšine vzoriek sedimentov boli hodnoty pomeru DDT/(DDE + DDD) nižšie ako 1, z čoho sa dá usúdiť, že väčšia časť pôvodne prítomného DDT sa rozložila na jeho hlavné metabolity a že DDT v sedimentoch vodných nádrží pochádza najmä z erodovaných poľnohospodárskych pôd. Hodnoty pomeru DDD/DDE ukázali, že predtým ako bol DDT deponovaný do sedimentov vodných nádrží, rozkladal sa najmä za aeróbnych podmienok.

Biodiesel Production from Spent Coffee Grounds

Abstract The residue after brewing the spent coffee grounds is an oil-containing waste material having a potential of being used as biodiesel feedstock. Biodiesel production from the waste coffee grounds oil involves collection and transportation of coffee residue, drying, oil extraction, and finally production of biodiesel. Different methods of oil extraction with organic solvents under different conditions show significant differences in the extraction yields. In the manufacturing of biodiesel from coffee oil, the level of reaction completion strongly depends on the quality of the feedstock oil. This paper presents an overview of oil extraction and a method of biodiesel production from spent coffee grounds.

APPLICATION OF FTIR-ATR SPECTROSCOPY FOR DETERMINATION OF GLUCOSE IN HYDROLYSATES OF SELECTED STARCHES

Abstract Fourier transform infrared spectroscopy was evaluated as an easy and simple analytical method for determination of starch residues after enzymatic hydrolysis. Different starch sources were liquefaction by α-amylase enzyme Termamyl SC for 25 minutes in autoclave. In the next step were starches solutions enzymatically hydrolysed by enzyme pollulanase Promozyme® for 24 hours to 60°C water bath. Total glucose in starch hydrolysate was determined using Fourier Transformed Infrared Spectroscopy (FTIR) with ATR accessory with diamante crystal by recording the absorption of different carbohydrate in spectral range from 700 - 4000 cm-1. Based on calibration curves of glucose the release of total glucose in hydrolysates was calculated.

Unconventional Type of Biomass Suitable for the Production of Biofuels

Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means for environmental and economic sustainability. Biofuels are divided into four generations. At present microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate and they also do not compete with food or feed crops, and can be produced on non-arable land. Microalgae have broad bioenergy potential because they can be used to produce liquid transportation and heating fuels (bioethanol, biodiesel). In this paper we present an overview about biofuels generation, especially about using duckweed for bioethanol production.

Catalytic Ozonization of Phenol with the Use of Alternative Catalysts

Phenol and its derivatives constitutes one of the most dangerous groups of organic chemicals which can cause many environmental and health risks. Therefore removal and degradation of phenol from aqueous solutions is one of the great industrial importance. Ozone is considered to be one of the most effective oxidizing agent for phenol degradation.. The objectives of this study are to examine the roles of added catalyst to rapid the process of phenol degradation by ozone.

Usage of FTIR-ATR as Non-Destructive Analysis of Selected Toxic Dyes

Abstract The degradation of the environment which is due to the discharge of polluting wastewater from industrial sources poses a real problem in several countries. Textile industries use large volumes of water in their operations, discharging thus large volume of wastewater into the environment, most of which is untreated. The wastewater contains a variety of chemicals from various stages of process operations, including desizing, scouring, bleaching and dyeing. The main purpose of this paper is to introduce Infrared Spectrometry with Fourier transformation as a non-destructive method for study, identifation and rapid determination of selected representatives of cationic (Methylene Blue), azo (Congo Red, Eriochrome Black T) and nitroso (Naphthol Green B) dyes. In conjunction with the ATR technique, FTIR offers a reliable detection method of dyes without extraction by other dangerous substances. Spectral interpretation of dye spectra revealed valuable information about the identification and characterization of each group of dyes.

Changes in structure and content humic substances in soil during the laboratory simulated fires

Abstract The paper deals with the process of thermal degradation of humic substances in soil samples exposed to increased temperature. To determine the basic properties of humic substances, humic and fulvic acids are used conventional fractionation chemical laboratory methods. To determine changes in the chemical structure, the method of use of FT-IR ATR spectroscopy technique.