Photocatalytic oxidation of methyl tert-butyl ether in presence of various phase compositions of TiO2

MTBE (methyl tert-butyl ether) represents a rising threat to the environment, especially drinking water, and its effective removal (with all by-products) is necessary. Even a very low concentration of MTBE makes the water undrinkable; therefore, an effective treatment has to be developed. This work is focused on MTBE photocatalytic oxidation in presence of various TiO2 photocatalysts with different phase composition prepared by different methods. It was confirmed the phase composition of TiO2 had the most significant influence on the photocatalytic degradation of MTBE. The rutile phase more easily reduces adsorbed oxygen by photogenerated electrons to superoxide radical, supporting separation of charge carriers. The presence and concentrations of by-products have to be taken into account as well. The conversion of total organic carbon (TOC) was used for the comparison, 40% of TOC was removed after 1 h of irradiation in presence of TiO2-ISOP-C/800 photocatalyst composed of anatase and rutile phase.Web of Science101art. no. 3

Water quality in a disturbed mining landscape, Czech Republic

In this article we assess the impact of water flow system and precipitation on choose hydro chemical parameter in water-bearing subside areas. Key findings of this study are significant correlation coefficient values obtained from the precipitation amount and occurrence of total phosphorus and phosphates. Therefore the significant effect of other anthropogenic activities on water reservoirs was excluded. The conclusion of this study is that inflowing water (in the case of relatively clean streams) and precipitation can have a positive influence on hydrochemical parameters in water-bearing subside areas and generally contribute to dilution

Evaluation of the Risk od Secondary Impact of Resuspension of Dust Particles from Thermally Active Dumps.

V minulosti vzniklo na Ostravsku několik desítek odvalů, které jsou pozůstatkem těžby černého uhlí. V dřívějších letech nebyly známy technologie, které by dokázaly zbavit hlušinu uhelných substancí, proto byla směs uhlí a hlušiny ukládaná na odvalech. Díky tomu docházelo často k samovznícení odvalů, z nichž některé jsou aktivní dodnes. Termicky aktivní odvaly negativně ovlivňují ovzduší anorganickými, organickými a plynnými emisemi. V rámci disertační práce se výzkum zaměřil na vybrané aktivní odvaly, jmenovitě se jedná o odval Ema, Hedvika a Heřmanice. Disertační práce se zabývá měřením vybraných toxických kovů (As, Cd, Cr, Cu, Ni, Pb, V a Zn) na PMx, v půdě a na zelené hmotě (listech) období červenec 2017 až duben 2018 a také vytvoření nových aparatur pro odběry PMx a PAHs. Toxické kovy v půdě byly posuzovány dle metodických pokynů MŽP - Indikátory znečištění a dále vyhodnoceny pomocí indexu geoakumulace. Podle indikátoru znečištění MŽP je na všech termicky aktivních odvalech překročen limit u arsenu 5–15 ×, ostatní kovy jsou pod limitem. U indexu geoakumulace všechny hodnoty vykazují první stupeň (neznečištěné až středně kontaminované), jen vzorek z odvalu Heřmanice vykazuje u arsenu stupeň dvě (mírně kontaminované). Na odvalech Hedvika a Heřmanice se nejčastěji vyskytují prachové částice o velikosti 10–25 μm v procentuálním zastoupení 25,2–25,4 %. Toxické kovy na PMx byly nejvíce zastoupeny na odvale Heřmanice. Nejvyšší naměřené koncentrace byly analyzovány u Cu = 429 mg kg-1, V = 239 mg kg-1 a As = 223 mg kg-1. Na odvale Heřmanice byly v půdě naměřeny nejvyšší koncentrace toxických kovů u Zn (164 mg kg-1), V (135 mg kg-1) a Pb (89 mg kg-1) a na odvale Ema u Cr (187 mg kg-1). Zelená hmota (listy) vykazuje největší rozdíl u vzorků omytých a neomytých, kde u Zn (169 mg kg-1) z odvalu Heřmanice a u vzorku z odvalu Hedvika Cr (16 mg kg-1), u ostatních kovů jsou hodnoty rozmezí 1-10 mg kg-1 sušiny. V rámci výzkumu byly provedeny i SEM analýzy, které poukázaly, že v analyzovaných vzorcích se vyskytoval toxický kov pouze na odvale Ema (V = 0,20 % hm) a na odvale Heřmanice (Cr = 2,01 % hm).In the past, several tens of dumps, which are the remains of black coal mining, originated in the Ostrava region. In earlier years, there were no technologies known to get rid of coal-based dirt, so a mixture of coal and tailings was bloated. This has often resulted in the self-extinguishing of ditches, some of which are still active today. Thermally active dumps adversely affect the atmosphere through inorganic, organic and gaseous emissions. In the dissertation the research focused on selected active dumps, namely the Ema, Hedvika and Hermanice. The dissertation deals with the measurement of selected toxic metals (AS, Cd, Cr, Cu, Ni, Pb, V and Zn) on PMx, soil and green masses (leaves) from July 2017 to April 2018 and also the creation of new collection devices PMx and PAHs. Toxic metals in the soil were assessed according to the methodological guidelines of the Ministry of the Environment - Pollution Indicators and further evaluated using the geoaccumulation index. According to the pollution indicator of the Ministry of the Environment, the arsenic limit is 5–15 × exceeded on all thermally active dumps, the other metals are below the limit. For the geoaccumulation index, all values show the first stage (unpolluted to moderately contaminated), only the sample from the dumps Hermanice shows a degree of arsenic of two (slightly contaminated). At the dumps of Hedvika and Hermanice the most frequent particles are 10-25 μm in the percentage of 25,2–25,4 %. Toxic metals on PMx were most represented at Hermanice. The highest measured concentrations were analyzed at Cu = 429 mg kg-1, V = 239 mg kg-1 and As = 223 mg kg-1. The highest concentrations of toxic metals in Zn (164 mg kg-1), V (135 mg kg-1) and Pb (89 mg kg-1) and in the soil Ema and Cr (187 mg kg-1). Green matter (leaves) show the largest difference in washed and unblended samples, where Zn (169 mg kg-1) from dumps Hermanice and Hedvika Cr sample (16 mg kg-1), with other metals ranging from 1-10 mg kg-1 dry matter. SEM analyzes were also carried out in the study, which showed that the toxic metal contained only the Ema (V = 0.20 % wt) and the Hermanice (Cr = 2.01 % wt) in the analyzed samples.546 - Katedra environmentálního inženýrstvívyhově

Removal of Hexavalent Chromium from Aqueous Matrix by Mixture of Cones in Continuous Flow System

Import 22/07/2015V teoretické části diplomové práce je popsána biosorpce v kontinuálním průtočném systému a její mechanismy na odstranění Cr(VI) s pomocí směsi šišek. Je zde vysvětlena základní problematika biosorpce, její využití, průběh probíhající chemická reakce. Dále se práce zabývá popisem kinetických modelů v dynamickém systémů za použití Thomasova modely, Yoon—Nelsonova modelu a BDST modelu. Práce je zaměřena na použitý biosorbent, tedy směs šišek. Popisuje chování a vlastnosti chromu ve vodném prostředí. Výsledky z experimentální části jsou znázorněny graficky.Za pomoci kinetických modelů v dynamických systémech bylo zjištěno, že nejlepší účinnost odstranění Cr(VI) bylo docíleno za pomocí výšky sloupce o velikosti 10 cm, tedy se jednalo o 31 g biosorbentu a ideální rychlosti prouděni roztoku iontu kovů je při rychlosti 10 ml min-1.Účinnost biosorbentu byla 78,75 %.The theoretical part of the thesis is described biosorption in a continuous flow system and its mechanisms to remove Cr (VI) with a mixture of cones. There, the basic issue biosorption, its use, process chemical reaction taking place. Furthermore, the work deals with the description of kinetic models in dynamic systems using models Thomas, Yoon-Nelson model and BDST model. The work is focused on using biosorbents, namely a mixture of cones. Describes the behavior and properties of chromium in an aqueous medium. Results from the experimental part are shown graphically.Using kinetic models of dynamic systems, it was found that the best efficiency of removal of Cr (VI) was achieved using column height of 10 cm, that was a 31 g biosorbents and ideal flow velocity of the solution of metal ions is at a rate of 10 ml min- 1.Účinnost biosorbents was 78.75%.Prezenční546 - Institut environmentálního inženýrstvívelmi dobř

The Use of Conifer Cones for Biosorption of Cr (VI) and Zn (II) from an Aqueous Solution

Import 26/06/2013Bakalářská práce se zabývá studiem biosorpce Cr(VI) a Zn(II) na šiškách jehličnatých stromů. Teoretická část je zaměřena na součastnou problematiku a její řešení, vlastnosti chromu a zinku, procesy biosorpce, vlastnosti biosorbentu. Experimentální část je zaměřena na konkurenci Cr(VI) a Zn(II) při biosorpci z vodného roztoku.This thesis deals with the study of Cr(VI) and Zn(II) biosorption for the cones of coniferous trees. The theoretical part is focused on the current issues and their solution properties of chromium and zinc biosorption processes, properties biosorbents. The experimental part is focused on the competition Cr(VI) and Zn(II) in the biosorption from aqueous solution.Prezenční546 - Institut environmentálního inženýrstvívýborn

The influence of structural properties on the adsorption capacities of microwave-assisted biochars for metazachlor removal from aqueous solutions

Biochars, carbonaceous materials prepared without the usage of chemical agents, are porous materials capable of adsorbing pollutants from ground-and surface waters. In this study, biochars prepared from various types of agricultural biomass were tested for the adsorptive removal of herbicide metazachlor from an aqueous environment. Banana wastes, red mombin seeds, corncob, cocoa pod husk, and coffee husk were used as precursors. Biochars were prepared with the aid of microwave treatment. The effect of precursor type on structure and adsorption was examined. Adsorption was controlled by a multistep mechanism, adsorption kinetics followed predominantly the pseudo-second-order model, adsorption isotherms suited to both Langmuir and Freundlich isotherms, depending on the particular biochar. Significant differences between the structural properties and adsorption capacities of the examined biochars were observed. The best adsorption properties for metazachlor uptake were observed for banana waste-based biochar, which had large, elongated pores, highest volume of micropores and one of the highest contents of polar functional groups. The maximum adsorption capacity, calculated from Langmuir isotherm, was 146.01 mg.g(-1), The adsorption capacity at equilibrium, obtained by kinetic measurements, was 27.25 mg.g(-1), the kinetic constant was 5.14.10- 3 dm3.min(-1) (both calculated from pseudo-second order model). Molecular modeling revealed that metazachlor molecules preferably entered two layer wide cavities containing one COOH group with their pyrazole rings.Web of Science103art. no. 10800