National Repository of Grey Literature 67 records found  beginprevious47 - 56nextend  jump to record: Search took 0.01 seconds. 
Microplastics removing from water
Ermis, Martin ; Himr, Daniel (referee) ; Štigler, Jaroslav (advisor)
This thesis deals with the occurrence of microplastics in water, the reasons for their potential elimination, and the possibilities leading to that. More specifically, it focuses on flotation as a process for removing microplastics from water. Flotation is further described from a theoretical point of view and its mathematical model is developed. The wettability of selected polymers is measured. The experiment performed to determine the efficiency of flotation as a process of treating water from microplastics is described. This efficiency is further compared to measured wettability.
Plastics and microplastics in water
Halašta, Tomáš ; Kučera, Tomáš (referee) ; Biela, Renata (advisor)
This bachelor thesis deals with the occurrence of plastics and microplastics in water and also is mainly devoted to microplastic in water treatment plants. The beginning of the work is devoted to plastics, their history, description of properties and what are the most commonly used plastics, which can be found in the form of microplastics. Next topic is devoted to the occurrence of plastics in waters, mainly seas and oceans, and especially in freshwater systems. Then the definition of microplastics and their sources and occurrence is given in the work. Furthermore, the work deals with studies on the occurrence of microplastics in drinking water and their removal at water treatment plants and the analysis of plastics microparticles. The conclusion is a summary of all available studies on microplastics in drinking water and water treatment plants.
Elimination of nanoplastics by cavitation and advanced oxidation processes
Kluknavská, Júlia ; Burda, Radim (referee) ; Rudolf, Pavel (advisor)
Táto práca sa zaoberá znečistením životného prostredia mikro a nanoplastami a ich možnou likvidáciou. Práca pozostáva z rešeršnej a experimentálnej časti. V rámci rešerše je opísaná problematika mikro a nanoplatov z hľadiska ich vzniku, disperzie do životného prostredia a živých organizmov. V závere rešeršnej časti sú opísané súčasné možnosti eliminácie mikro a nanoplastov pri čistení odpadových vôd. Súčasné riešenia sú založené prevažne na filtrácii, ktorá však zo svojej podstaty nemôže byť absolútna. Bol vyslovený predpoklad, že pomocou zariadenia CaviPlasma by bolo možné eliminovať mikro a nanoplasty z odpadových vôd. Cieľom práce bolo experimentálne overiť tento predpoklad. Skúšobnou vzorkou bola suspenzia vody a polyamidových častíc, ktorá bola následne vystavená pôsobeniu kavitácie a plazmového výboja. Pri experimente nedošlo ku zničeniu častíc a ani ich k viditeľnému porušeniu. Ukázalo sa však, že plazmový výboj môže iniciovať zhlukovanie sa častíc až do takej miery, že sú pozorovateľné kontinuálne štruktúry mikroplastov. Tento jav by mohol byť potenciálne prospešný pri zachytávaní mikročastíc filtráciou.
Fate of microplastics in soil
Kameníková, Eliška ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
The problems with microplastics, small plastic particles contaminating the environment, is a subject of heated discussions today. It has been recognized that the microplastics are not inert, but instead they have an impact on all enviromnental compartments. There are studies describing the negative effects of microplastics, for example on fauna and flora or on human health, but the effects on soil quality have not been sufficiently described. The aim of this thesis was to assess the short and medium term effects that microplastics could have on the soil. In this work, a series of experiments were performed to elucidate the fate of microplastics in the soil. Changes in soil organic matter thermal properties, soil respiration, amount of water and soil aggregation depending on the incubation time were monitored. Three types of agricultural land (chernozem, cambisol and phaeozem), which were contaminated with different concentrations od PET and tyre rubber, were tested. The results confirmed the specific effects of microplastics on soil properties, which were observed in non-incubated samples (i.e. at the time of incubation 0 months), microplastics did not behave inertly in the soil and affected, for example, soil properties, texture and respiration.
Removal of microplastics from water
Skalníková, Andrea ; Pivokonský, Martin (advisor) ; Čermáková, Lenka (referee)
The aim of this diploma thesis is to investigate the removability of microplastsic particles with different shapes (fragments, sphers, fibers) by standard water treatment process, such as coagulation, filtration and sedimentation. For the experimental purpose in this study, polyvinyl chloride with a size ≤ 50 μm and a density of 1.38 g/cm3 , was used as a representative of microplastics. The coagulation has been provided by ferric sulphate in pH range 5, 6, 7 and 8 and at a diferent dose of coagulant 20, 40, and 60 mg/l. The study results has shown, that the coagulation efficiency of polyvinyl chloride particles were affected by pH. The optimal value of pH has been 7 at the coagulant dose of 20, 40 and 60 mg/l. The presence of polyvinyl chloride shown a positive effect on coagulation. It has been reflected in a reduction of the residuals of iron concentration after coagulation, at pH 5-7. Solution with polyvinyl chloride contained 1,2 mg/l dissolved organic carbon. After fitlration the concentration decreased up to 70 % at pH 7 at dose of coagulant 40 and 60 mg/l. Experiments have shown that polyvinyl chloride particles are capable of faster sedimentation after coagulation. The flocs formed during coagulation interacted effectively with the polyvinyl chloride particles and facilitate their removal...
Study of microplastic sorption properties
Hlaváčková, Hana ; Kučerík, Jiří (referee) ; Řezáčová, Veronika (advisor)
There is currently an effort to replace conventional plastics with biodegradable products that will have the ability to replace these substances. One of the possible biodegradable felt, which is currently being studied in detail, is also poly (3-hydroxybutyrate), which is produced by bacteria. This bachelor thesis deals with the sorption of selected substances on poly(3-hydroxybutyrate) microparticles. Substances whose contamination of water sources is a significant problem today have been selected for this work. Specifically, the sorption of the nonsteroidal anti-inflammatory substance ibuprofen, the triazole fungicide tebuconazole and the most common drug caffeine on PHB particles, which fall in the size of the microplastic group, were studied. The method of liquid chromatography with mass detection was used for analyzes.
Microplastics in soil
Dvořáková, Alena ; Kučerík, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with the appraisal of the suitability of infrared spectroscopy for the identification of plastics and microplastics in soils. Available techniques were DRIFT (diffuse reflectance) and ATR (attenuated total reflectance). Mixtures of model soil and pure PET were prepared for analysis in various concentrations. Furthermore, a total of 21 samples of soil and 3 samples of compost were evaluated. The obtained data were used for interpretation of infrared spectra, creation of calibrations of PET using ATR and DRIFT methods. Part of the work was the evaluation of validation models using spectra and basic soil parameters.
Influence of biodegradable polymers microplastics on properties of soil organic matter
Denková, Pavla ; Řezáčová, Veronika (referee) ; Kučerík, Jiří (advisor)
The microplastics contamination is an issue observed in all environmental compartments. Currently, the trend is to replace the synthetic polymers by biodegradable ones, which are expected to degrade faster due to omnipresent microorganisms. However, this assumption may not correspond with the reality. In nature, biodegradation can last long or not whatsoever and the microparticles of biodegradable polymers can remain in soil the same way as particles of synthetic polymers. The effect of microparticles of biodegradable polymers on soil´s biota has already been studied, but the effect on the properties of soil and water in the soil has not been elucidated yet. This thesis deals with the influence of microparticles of biodegradable plastics on the physico-chemical properties of soil organic matter, especially on the behavior of water in the soil system under arid and semiarid conditions. Microparticles of poly(R-3-hydroxybutyrate), abbreviated as P3HB, were used as a model biodegradable polymer and were introduced into the soil in various concentrations. To determine the evaporation enthalpy of water and stability of water bridges that affect (stabilize) the physical and chemical structure of soil organic matter Differential Scanning Calorimetry (DSC) was used. Simultaneously was also measured their effect on water holding capacity of soil organic matter. Under experimental conditions, P3HB microplastics were found to reduce evaporation enthalpy, which facilitates drying of soil organic matter. Nevertheless, their effect on final water holding capacity was relatively low. Besides, we observed a negative effect on the stability of water molecule bridge that connect segments of soil´s organic components. Thus, P3HB microparticles in soil could pose a risk due to their influence on the water retention mechanism in soil under arid and semiarid conditions.
Microplastics and their removal from water using sorbents.
Spáčilová, Markéta ; Dytrych, Pavel ; Krejčíková, Simona ; Fajgar, Radek ; Šolcová, Olga
The occurrence of contaminants in water sources, microplastics or other organic pollutants, has been an increasing environmental problem. This issue is related to mapping of their occurrence in an aquatic environment and with finding of possible ways regarding their elimination. The prepared microplastic particles of five most-frequently used plastics (polyethylene, polyamide, polytetrafluoroethylene, polyethylene glycol terephthalate and polystyrene) were characterized by the scanning electron microscopy (SEM), the Raman spectroscopy and the infrared spectroscopy (IR). The obtained microplastic particles were used for preparation of simulated water contaminated with microplastics. The prepared simulated samples of water contaminated with microplastics were used for the development of a methodology for determining the number of contained microplast particles. Furthermore, the possibilities of a microplastic removal from simulated samples by sorbents based on natural bentonites and zeolites were tested. It was confirmed that the effectiveness of sorbents depends on their composition and textural properties and could be increased by their modification.

National Repository of Grey Literature : 67 records found   beginprevious47 - 56nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.