Environmental risks after remediation of soils contaminated with potentially toxic elements using chelating agent

Namen doktorske dizertacije je prispevati k boljšemu razumevanju tehnologije pranja tal s kelatnim ligandom EDTA, raziskati vpliv EDTA na tla in širše okolje in s tem opredeliti, ali lahko to tehnologijo označimo kot zeleno in trajnostno rešitev za remediacijo tal, onesnaženih s potencialno strupenimi elementi. Z dodajanjem ničvalentnega železa v tla med postopkom remediacije smo preprečili emisije ostankov kelatov EDTA s strupenimi elementi iz tal že 6 dni po remediaciji pH-nevtralnih karbonatnih tal in 7 dni po remediaciji kislih tal. Raziskali smo vpliv remediacije tal na razgradnjo herbicidov, kot pomembne funkcije kmetijskih tal. S pomočjo FOMC modela smo določili vrednost DT50 za posamezne herbicide. Pri kislih tleh se je DT50 povečala pri izporoturonu za 16 %, bentazonu 21 %, mekoprop-P-ju 42 %, S-metolaklor-u 111 %. Pri karbonatnih tleh se je DT50 remediiranih tal pri mekoprop-P-ju povečala za 3 %, medtem ko se je pri ostalih treh znižala za do 30 %. Vedno pa je bila DT50 manjša kot povprečna, objavljena v literaturi. Nadalje smo učinkovitost in varnost uporabe EDTA primerjali z biorazgradljivimi kelatnimi ligandi GLDA, EDDS in IDS. S kvantitativno analizo, pri kateri smo uporabili osem različnih za remediacijo relevantnih kategorij, je pokazala na vrstni red primernosti: EDTA> GLDA> IDS> EDDS. Remediirana tla so omogočala podobno rast ajde (F. esculentum) in celo boljšo rast kitajskega zelja (B. rapa) v primerjavi z originalnimi tlemi. Aktivnosti stresnih encimov antioksidativnega preventivnega sistema v kitajskem zelju in fizikalne lastnosti tal so bile podobne pri remediiranih in originalnih tleh. Podobno je bilo tudi funkcioniranje tal, ki smo ga ocenili preko merjena mikrobnega dihanja in aktivnosti talnih encimov, ki sodelujejo pri kroženju C, N in P v tleh. Tla, remediirana z EDTA, so v primerjavi s tlemi, remediiranimi z biorazgradljivimi kelatnimi ligandi, funkcionirala bolje. Vpliv remediacije na tla in rastline: ajda, špinača, radič, motovilec, solata, česen, čebula, por, korenje in koleraba, smo preučili tudi v realnih razmerah na demonstracijskem vrtu z 9 gredicami, vsaka s 1,75 t zračno suhih tal. Kljub temu, da so bila pred remediacijo tla nadpovprečno onesnažena (Pb 1854, Zn 3833 in Cd 21 mg kg–1), smo pri večini rastlin uspeli zmanjšati koncentracijo Pb pod zakonsko določeno mejo, razen pri ajdi in korenju. Koncentracije Cd so bile pri večini rastlin pod ali blizu zakonsko določene meje, le pri korenju, špinači in radiču so bile meje prekoračene. Remediacija z EDTA je zmanjšala vsebnost Pb, Zn in Cd v tleh za 71, 28 in 53 %, ni pa imela večjega pomembnega vpliva na lastnosti in funkcioniranje tal.The aim of the doctoral dissertation was to contribute to a better understanding of soil washing technology using the chelate ligand EDTA, to investigate the effects of EDTA on soil and the environment in a broader sense, and to determine whether this technology can be considered a green and sustainable solution for the remediation of soil contaminated with potentially toxic elements. By adding zero-valent iron to the soil during the remediation process, we prevented the emission of residues of EDTA chelates with toxic elements from the soil as early as 6 days after the remediation of pH-neutral carbonate soils and 7 days after the remediation of acidic soils. We investigated the impact of soil remediation on herbicide degradation as an important function of agricultural soil. Using the FOMC model, we determined the DT50 value for individual herbicides. In acidic soils, DT50 increased by 16% with isporoturon, 21% with bentazone, 42% with mecoprop-P and 111% with S-metolachlor. In carbonate soils, the DT50 value of remediation soils for mecoprop-P increased by 3%, while it decreased by up to 30% for the other three herbicides. However, the DT50 was always lower than the average value published in the literature. In addition, the efficacy and safety of EDTA was compared with the efficacy and safety of biodegradable chelate ligands GLDA, EDDS, and IDS. A quantitative analysis, in which we used eight different remediation-relevant categories, showed the order of suitability: EDTA> GLDA> IDS> EDDS. The remediated soil allowed a similar growth of buckwheat (F. esculentum) and an even better growth of Chinese cabbage (B. rapa) compared to the original soil. The activity of the stress enzymes of the antioxidant prevention system in Chinese cabbage and the physical properties of the soil were similar in the remediated and original soils. Similarly, soil function was assessed by measuring microbial respiration and the activity of soil enzymes involved in the circulation of C, N, and P in soil. Soils remediated with EDTA performed better compared to soils remediated with biodegradable chelate ligands. The effects of remediation on soil and plants: buckwheat, spinach, radicchio, lamb`s lettuce, lettuce, garlic, onion, leek, carrot, and kohlrabi were also examined under realistic conditions in a demonstration garden with 9 raised beds, each with 1.75 t of air-dry soil. Despite the fact that the soil had an above-average contamination before the remediation (Pb 1854, Zn 3833 and Cd 21 mg kg–1), we succeeded in reducing the Pb concentration in most plants, with the exception of buckwheat and carrots, to below the legal limit. Cd concentrations in most plants were below or near the legal limit in most plants, only carrots, spinach, and chicory exceeded the limits. Remediation with EDTA reduced the Pb, Zn, and Cd contents in soil by 71, 28, and 53%, respectively, but had no significant effect on soil properties and function

Changes in organic matter composition caused by {EDTA} washing of two soils contaminated with toxic metals

Two soils contaminated with potentially toxic metals (PTMs) contrasting in pH and mineralogy were remediated with CaEDTA, and changes in soil organic matter (SOM) composition were investigated. Previous studies showed no significant loss of SOM from CaEDTA-treated soils, but the results of our study reflected significant decreases (from 46 to 49%) in the free fraction of humic acids (HAs). Remediation affected the composition of the free HA fraction via disturbance of intermolecular bonds - an increase in phenolic and aromatic groups with a simultaneous decrease in carbohydrates - which was confirmed by FTIR spectroscopy in both soils. Because non-radical molecules such as carbohydrates were selectively removed, the concentration of free radicals in the free HA fraction increased in acidic soil. The bound fraction of HAs and fulvic acids (FAs) in SOM, which are important due to their stability and the permanent effects they have on the soil's physical properties, remained unchanged in both remediated soils. The effect of soil recultivation was observed only in the excitation emission matrix (EEM) fluorescence spectra of HAs. In terms of SOM, CaEDTA soil washing can be considered moderately conservative; however, the restoration of free humic fractions is likely to be a long-term process

Advantages and disadvantages of plastic packaging

Plastična embalaža je ena izmed glavnih predstavnic embalaže. V današnjem času predstavlja plastika nenadomestljiv material predvsem z vidika svojih prednosti, ki se navezujejo tako na izdelavo kot tudi ceno. Gre za nepogrešljivo vrsto embalaže, glede katere v zadnjih letih prihajajo predvsem v ospredje njene negativne lastnosti, kot je onesnaževanje naravnih habitatov različnih bitij. Kljub zavedanju ob takšnih globalnih težavah je plastika oziroma plastična embalaža še vedno prisotna. V diplomskem delu smo raziskovali področje plastične embalaže, pri čemer smo želeli ugotoviti, zakaj jo kljub njenim vse glasnejšim negativnim vplivom na okolje še vedno uporabljamo v gospodinjstvih in v svojem vsakdanu. V teoretičnem delu smo predstavili področje plastike, njeno zgodovino in nastanek, prednosti in slabosti plastične embalaže, njeno onesnaževanje ter recikliranje. V eksperimentalnem delu smo s pomočjo spletne ankete in pogovora s fokusno skupino pridobili potrebne odgovore in informacije o uporabi in njenem poznavanju. Sestavili smo vprašalnik, ki smo ga uporabili tako pri spletni anketi kot tudi pri pogovoru s fokusno skupino. Spletno anketo smo izdelali na portalu www.1ka., medtem ko smo pogovor s fokusno skupino izvedli s skupino študentov Naravoslovnotehniške fakultete. S pomočjo odgovorov smo preverili, ali obstajajo razlike glede na spol, starost, zaposlitev in kraj bivanja pri poznavanju plastične embalaže. Kljub vse večjemu spodbujanju k manjši uporabi plastične embalaže se njena prisotnost morda ne bo zmanjšala, saj je zelo koristna na različnih področjih, kar kažejo tudi rezultati ankete. Ugotovili smo, da se večina ljudi zaveda težav plastične embalaže ter stremi k izboljšanju in spremembam predvsem pri pakiranju živil.Plastic packaging is one of the main representatives of packaging. Nowadays, plastic represents an irreplaceable material, especially from the point of view of its advantages, which are related to both production and price. It is an indispensable type of packaging, but in recent years its negative properties have come to the fore, such as the pollution of the natural habitats of various creatures. Despite awareness of such global problems, plastic or plastic packaging is still present. In our diploma thesis, we researched the field of plastic packaging, where we wanted to find out why, despite its increasingly loud negative effects on the environment, it is still used in households and in our everyday life. In the theoretical part, we presented the field of plastics, its history and creation, the advantages and disadvantages of plastic packaging, its pollution and recycling. In the experimental part, with the help of an online survey and a conversation with a focus group, we obtained the necessary answers and information about the use and its familiarity. We assembled a questionnaire that we used both in the online survey and the discussion with the focus group. We created an online survey on the portal www.1ka., and we conducted a conversation with the focus group with a group of students from the Faculty of Science and Technology. With the help of the responses, we checked whether there are differences in knowledge of plastic packaging according to gender, age, employment and place of residence. Despite the increasing push to reduce the use of plastic packaging, its presence may not decrease, as it is beneficial in various fields, as the survey results also show. We found that most people are aware of the problems of plastic packaging and strive for improvement and changes, especially in food packaging

RUSSIAN INTELLIGENCE SERVICE FROM IT\u27S INCEPTION UNTIL TODAY

Komuniciranje je del našega vsakdana saj je nujno potrebno za funkcioniranje same družbe. Brez obveščanja in s tem tesno povezanih obveščevalnih služb bi države le težko funkcionirale, saj ne bi bilo pretoka informacij, ki so v današnjem svetu in času najdragocenejši vir moči. Samo diplomsko delo je kratek prerez obveščevalne službe, pojmov povezanih z njo ter nastanka in razvoja ruske obveščevalne službe od začetka pa do danes. Na samem začetku je predstavljen pojem obveščevalne službe. Opisane so vse podskupine povezani z obveščevalno službo prav tako kratka zgodovina samega nastanka obveščanja. Kasneje v naslednjih poglavjih se besedilo prevesi v jedro diplomskega dela saj začne predstavljati začetek ruske obveščevalne službe KGB. Podrobneje se dotakne začetnikov obveščanja v rusiji od Ivana Groznega pa vse do številnih varnostnih služb kot so Opričina, Tajni biro, Preobraženski biro, Tretja sekcija in Ohrana. Glavni del diplomskega dela pa je namenjen podrobnejšemu opisu predhodnic KGB, samemu razvoju, funkcijam ter organizacijski strukturi KGB. Predhodnice so slovele predvsem po svoji krutosti. Med najbolj znane predhodnice sigurno spada CHEKA katero je vodil Felix Dzerdzinski, ki je imel zelo dobre vodstvene sposobnosti obenem pa je bil tudi zelo hladen in krut. Za najbolj kruto izmed vseh pa je veljala NKVD saj v času njenega delovanja ni obstajala nobena druga kazen razen likvidacija. V zadnjih poglavjih pa se diplomsko delo dotakne še aktualne obveščevalne službe FSB, z njo povezane politike in Vladimirja Putina ter odmevnih primerov Aleksandra Litvinenka in Ane Politkovske.Communication is part of our lives because it is necessary for the functioning of society itself. Without communication, and the closely related intelligence the functioning of countries would be very difficult, because there would be no flow of information and in today\u27s world and time those are most valuable source of power. This study is a short section of the intelligence services, concepts associated with it, and the formation and development of the Russian intelligence service from the beginning until today. At the beginning is presented the concept of intelligence, describing all the subgroups relating to the intelligence service and also a brief history of the emergence of information. Later in the following chapters, the text turns into the core of the thesis begins to representing first steps of the Russian intelligence service KGB. There is a detail description of beginnings of intelligence in Russia from Ivan the Terrible through to a number of security services such as Opričina, Secret bureau, bureau Preobraženski, Third Section, and Ohrana. The main part of the thesis is devoted to a more detailed description of the precursors of the KGB, the very development, functions and organizational structure of the KGB. Predecessors were famous primarily for his cruelty. Among the most famous predecessor certainly belongs Cheka which was headed by Felix Dzerdzinski, who had a very good management skills while he was also very cold and cruel. For the most cruel of all, it is considered the NKVD, at the time of its operation there was no other penalty than liquidation. In the last chapter, the thesis turns to current intelligence service FSB, the associated policies and Vladimir Putin, and high-profile cases of Alexander Litvinenko and Anna Politkovskaya

Employment challenges for young people entering the labour market in Slovenia

Prehod na trg dela predstavlja eno od največjih prelomnih točk v posameznikovem življenju, ki vpliva tudi na njegovo družbeno okolje. Diplomsko delo obravnava različne dejavnike, ki vplivajo na položaj mladih na trgu dela, vključno s področjem urejanja trga dela in brezposelnostjo mladih, kot tudi družbeno-ekonomske dejavnike. Z razumevanjem dejavnikov, ki vplivajo na ta prehod, med drugim tudi spreminjajočih se struktur trga dela, pričakovanj mladih in vpliva vladnih politik, naj bi ta študija prispevala k bolj utemeljeni obravnavi strategij za lažji prehod mladih na trg dela. Posebna pozornost je prav tako namenjena vplivu fleksibilnosti trga dela, ki je v Sloveniji močno izrazita. V diplomskem delu želim raziskati tudi pričakovanja in realnost mladih pri vstopu na trg. Za boljše razumevanje trga dela je treba razumeti tudi stran ponudbe, zato v diplomskem delu obravnavam tudi pričakovanja delodajalcev do zaposlovanja mladih.The transition to the labour market is one of the biggest transitions in an individual\u27s life, with implications for their social environment. The thesis examines various factors affecting the labour market situation of young people, including labour market regulation and youth unemployment. By understanding the factors influencing this transition, including changing labour market structures, youth expectations and the impact of government policies, this study aims to contribute to a more grounded consideration of strategies to facilitate young people\u27s transition to the labour market. Particular attention is also given to the impact of labour market flexibility, which is very pronounced in Slovenia. In this thesis we will explore the expectations and realities of young people entering the labour market. To better understand the labour market, it is also necessary to understand the supply side, so in this thesis I will also look at the expectations employers have of employing young people

Simultaneous removal of arsenic and toxic metals from contaminated soil

Soil chemistry of toxic metalloids and metals differs, making their simultaneous removal difficult. Soil contaminated with As, Pb, Zn and Cd was washed with oxalic acid, Na-dithionite and EDTA solution. Toxic elements were removed from the washing solution by alkalinisation with CaO to a pH 12.5: As was co-precipitated with Fe from Fe-EDTA chelate formed after the soil washing. The toxic metals precipitated after substitution of their EDTA chelates with Ca. The novel method was scaled up on the ReSoil® platform. On average, 60, 76, 29, and 53% of As, Pb, Zn, and Cd were removed, no wastewater was generated and EDTA was recycled. Addition of zero-valent iron reduced the toxic elements’ leachability. Remediation was most effective for As: phytoaccessibility (CaCl$_2$ extraction), mobility (NH$_4$NO$_3$), and accessibility from human gastric and gastrointestinal phases were reduced 22, 104, 6, and 51 times, respectively. Remediation increased pH but had no effect on soil functioning assessed by fluorescein diacetate hydrolysis, dehydrogenase, β-glucosidase, urease, acid and alkaline phosphatase activities. Brassica napus produced 1.9 times more biomass on remediated soil, accumulated no As and 5.0, 2.6, and 9.0 times less Pb, Zn and Cd, respectively. We demonstrated the novel remediation technology as cost-efficient (material cost = 41.86 € t$^{−1}$) and sustainable