Negative effect of clay fillers on the polyvinyl alcohol biodegradation: technical note

This work focuses on polyvinyl alcohol (PVA) biodegradation in the presence of mineral clays in an aqueous aerobic environment. PVA with a degree of hydrolysis of 88% and 72% was used for the experiments. The selected group of mineral clays (nanofillers for polymers) of montmorillonite (MMT) Cloisite (R) Na+; organo-modified montmorillonite (OMMT) Cloisite (R) 20A, Cloisite (R) 30B; waste kaolin; kaolin; and zeolites were prepared by synthesis of the aforementioned kaolins. The level of biodegradation was measured using a respirometer, Micro-Oxymax, and evaluated according to CO2 production. Results of this test indicate a negative effect on PVA biodegradability in the presence of MMT Cloisite (R) Na+ and Cloisite (R) 30B. It has been found that PVA biodegradability in the presence of no adapted inoculum was adversely affected by the biocidal effects of the organic modifier of Cloisite (R) 30B. In this case, PVA 88-8 biodegradation decreased by 71% and PVA 72-10 biodegradation dropped by 58%. Furthermore, the sorption of PVA on the Cloisite (R) Na+ in the range of 40%-45% was demonstrated in the following research.Tomas Bata University in Zlin [IGA/FT/2018/009]; Ministry of Education, Youth, and Sports of the Czech Republic [LO1504

PVP Based Materials: Biodegradation in Different Environments

The research deals with biodegradation of films prepared from polyvinylpyrrolidone and polylactic acid (PVP/PLA). Biodegradation of PVP/PLA films was supported by the following additives: 1-methyl-2-pyrrolidone, 1-octyl-2-pyrrolidone, acrylamide and N-acetyl-L-phenylalanine according to the previous study. The films were prepared by a solvent casting technique. Biodegradation was observed using the respirometric method in different environments. The films subjected to biodegradation were analyzed by scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that the films are substantially degraded, but not in the biological way; PVP was quickly removed in presence of water because of its easy solubility. In contrast, this fact could support biodegradation of PLA, which becomes more available for microorganisms when PVP leaves PLA matrix. © 2017 by Marketa Julinova.Tomas Bata University in Zlin [IGA/FT/2017/003]; projects of Ministry of Education, Youth, and Sports of the Czech Republic within the NPU I program [LO1504

Comprehensive biodegradation analysis of chemically modified poly(3-hydroxybutyrate) materials with different crystal structures

This work presents a comprehensive analysis of the biodegradation of polyhydroxybutyrate (PHB) and chemically modified PHB with different chemical and crystal structures in a soil environment. A polymer modification reaction was performed during preparation of the chemically modified PHB films, utilizing 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexane as a free-radical initiator and maleic anhydride. Films of neat PHB and chemically modified PHB were prepared by extrusion and thermocompression. The biological agent employed was natural mixed microflora in the form of garden soil. The course and extent of biodegradation of the films was investigated by applying various techniques, as follows: a respirometry test to determine the production of carbon dioxide through microbial degradation; scanning electron microscopy (SEM); optical microscopy; fluorescence microscopy; differential scanning calorimetry (DSC); and X-ray diffraction (XRD). Next-generation sequencing was carried out to study the microbial community involved in biodegradation of the films. Findings from the respirometry test indicated that biodegradation of the extruded and chemically modified PHB followed a multistage (2-3) course, which varied according to the spatial distribution of amorphous and crystalline regions and their spherulitic morphology. SEM and polarized optical microscopy (POM) confirmed that the rate of biodegradation depended on the availability of the amorphous phase in the interspherulitic region and the width of the interlamellar region in the first stage, while dependence on the size of spherulites and thickness of spherulitic lamellae was evident in the second stage. X-ray diffraction revealed that orthorhombic α-form crystals with helical chain conformation degraded concurrently with β-form crystals with planar zigzag conformation. The nucleation of PHB crystals after 90 days of biodegradation was identified by DSC and POM, a phenomenon which impeded biodegradation. Fluorescence microscopy evidenced that the crystal structure of PHB affected the physiological behavior of soil microorganisms in contact with the surfaces of the films.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Horizon 2020, (862910); Univerzita Tomáše Bati ve Zlíně, UTB, (IGA/FT/2022/006, IGA/FT/2023/002)European Union's Horizon 2020 Research and Innovation Program [862910]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/FT/2023/002, IGA/FT/2022/006]; Ministry of Education, Youth and Sports of the Czech Republic [90254

Polyvinylalkohol a polyvinylpyrrolidon : polymerní xenobiotika

PrezenčníNeuvedenoNeuveden

Removal of phthalates from aqueous solution by different adsorbents: A short review

This work presents a short review of adsorptive materials proposed and tested for removing phthalates from an aqueous environment. The objective is not to present an exhaustive review of all the types of adsorbents used, but to focus on selected types of "innovative" materials. Examples include modified activated carbon, chitosan and its modifications, β-cyclodextrin, and specific types of biomass, such as activated sludge from a wastewater treatment plant, seaweed and microbial cultures. Data from the literature do not confirm the existence of a broad-spectral adsorbent with high sorption efficiency, low production costs and environmentally friendly manufacture. According to the coefficients of Freundlich's isotherm, the most promising adsorbent of those mentioned in this work appears to be the biomass of activated sludge, or extracellular polysaccharides extracted from it. This material benefits from steady production, is cheap and readily available. Nevertheless, before putting it in practice, the treatment and adaptation of this raw material has to be taken into consideration. © 2011 Elsevier Ltd

Conditions influencing biodegradability of PVA and modified films

Byl sledován průběh biologického rozkladu polyvinylalkoholu (PVA) a jeho směsí s bílkovinným hydrolyzátem v závislosti na jeho vlastnostech a podmínkách rozkladu. Biologický rozklad byl prováděn ve vodném aerobním prostředí v přítomnosti aktivovaného kalu z městské čistírny odpadních vod. Bylo zjištěno, že vlastnosti PVA, charakterizované viskozitou jeho 4% vodného roztoku a %hydrolýzy, mají významný vliv na biologickou rozložitelnost PVA. Bylo také prokázáno, že hmotnostní poměr mezi bílkovinným hydrolyzátem a změkčovadlem ve směsných foliích významně ovlivňuje biologickou rozložitelnost samotného PVA.Study focused on the biodegradation course of polyvinyl alcohol (PVA) and of its blends with protein hydrolysate dependently on its properties and biodegradation conditions. Biodegradation was conducted in an aqueous aerobic environment in the presence of activated sludge from the municipal wastewater treatment plant. It was found that properties of PVA, characterised by its 4% aqueous solution and percentage of hydrolysis, exert significant influence on PVA biodegradability. It was proved that the mass ratio of protein hydrolysate to plasticizer in mixed films significantly affects biodegradability of PVA itself

Determining biodegradation of synthetic materials in biotic environment

Práce dokumentuje skutečnost, že při rozkladu směsných filmů aktivovaným kalem adaptovaným na PVA bylo prokázáno, že hmotnostní poměr mezi modifikátorem (škrob, bílkovinný hydrolyzát) a změkčovadlem (glycerínem) významně ovlivňuje biologickou rozložitelnost samotného PVA.This work described that it was proved in degradation of mixed films by means of PVAL-adapted activated sludge that the mass ratio of modifying agent (starch, collagen hydrolysate) to plasticising agent significantly affects biodegradability of PVAL itself

Water-soluble polymeric xenobiotics – Polyvinyl alcohol and polyvinylpyrrolidon – And potential solutions to environmental issues: A brief review

This paper describes a potential environmental problem closely linked with the global production of water-soluble polymers such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). Both polymers make up the components of a multitude of products commonly utilized by industries and households. Hence, such a widespread use of PVA and PVP in the industrial sector and among consumers (the concentration of PVP in urban wastewater is approximately 7 mg/L) could pose a considerable problem, particularly to the environment. To this end, many publications have recently highlighted the poor biodegradability of PVA, in principle influenced by numerous biotic and abiotic factors. Facts published on the environmental fate of PVP have been scant, basically reporting that it is a biologically resistant polymer. As a result, the commercially produced water-soluble polymers of PVA and PVP are essentially non-biodegradable and possess the capacity to accumulate in virtually all environmental media. Consequently, there is a chance of heightened risk to the very environmental constituents in which PVA and PVP accumulate, depending on the routes of entry and transformation processes underway in such constituents of the ecosystem. This assumption is confirmed by the findings of initial research, which is worrying. Herein, PVA was detected in a soil environment, while a relatively high concentration of PVP was found in river water. A review of the literature was conducted to summarize the current state of knowledge concerning the fate of PVA and PVP in various environments, thereby also discerning potential solutions to tackle such dangers. This paper proposes methods to enhance the biodegradability of materials containing such materials; for PVA this means utilizing a suitable polysaccharide, whereas for PVP this pertains to actuating applications that induce substances to degrade. Accordingly, while it is understandable that this work cannot fully address all the issues associated with polymeric xenobiotics, it can still serve as a guide to discerning an economically viable solution, and provide a foundation for further research. © 2018 Elsevier LtdIGA/FT/2018/009, UTB, Univerzita Tomáše Bati ve ZlíněTomas Bata University in Zlin [IGA/FT/2018/009

An effect of salt concentration and inoculum size on poly(vinyl alcohol) utilization by two sphingomonas strains

Due to its widespread use and water solubility, poly(vinyl alcohol) (PVA) has the potential to find its way into various water or soil ecosystems. Despite the fact that many bacterial species with the capacity of utilizing PVA have been found and described, the influences of some environmental factors on their capabilities to biodegrade PVA have not been adequately studied. Therefore, study was made of the effects of two environmental factors on PVA degradation exhibited by two Sphingomonas strains. Both strains originated from common wastewater treatment plants, and proved to be considerably sensitive to increased inorganic salt concentrations; in brief, 13.3 mmol/l either of phosphate or chloride ions significantly delayed the degradation process or inhibited it entirely. In contrast to such halosensitivity, both strains were able to rapidly utilize PVA under suitable conditions, even when low inoculum sizes were applied. Initial cell densities, ranging from 100 to 107 cells/ml, were used in two series of degradation trials and PVA degradation occurred in all cases; merely delays extending over several days in the degradation process were noted when inoculum sizes of 100–103 cells/ml were applied. © 2017, Springer Science+Business Media, LLC.[IGA/FT/2016/012

Screening of the spatial distribution of risk metals in topsoil from an industrial complex

For the sustainable development of urban areas, it is necessary to identify if environmental pollution exists and where hot spot pollution sources lie. In this study, 280 topsoil samples were collected from an industry estate in Zlin (the Czech Republic). In these samples, the presence of toxic metal was analyzed by energy dispersed X-Ray fluorescence (ED-XRF), and statistical analysis revealed that the major anthropogenic contaminants in the topsoil were Pb, Zn and Sn. Further contaminant analysis by atomic absorption spectrometry (AAS) determined the maximum contents of 28558.47 mg/kg for Pb, 1132.35 mg/kg for Sn and 2865.22 mg/kg for Zn in selected topsoil samples. According to soil pollution index results, the main proportion of topsoil is contaminated, with the possible sources of contamination being traffic and a nearby municipal heating plant. This study proves that the combination of preliminary ED-XRF topsoil analysis, a multivariative statistical approach, AAS analysis and the geographical information system (GIS) is effective and together form a powerful tool for mapping topsoil contamination and conducting an environmental risk assessment