waste product utilization
Dotaz
Zobrazit nápovědu
Polyurethane has a good insulation characteristic, and it is widely used as an insulation and lining material for refrigerators. Nevertheless, at the end of a product's lifetime, serious problems arise related to waste management. Recently, energy recovery has been marked as a promising solution, especially, waste-to-energy applications. To find an appropriate application for such waste, a thermal analysis was performed. An experimental analysis of polyurethane (PU) waste material was performed by the method of pyrolysis gas chromatography with mass spectrometric detection (Py-GC/MS) at various pyrolytic temperatures, namely, at 500, 600 and 700 °C. Waste polyurethane foam was conducted to investigations in the form of a bulk sample and sorted grain-size samples with a goal to detect the chemical composition of the pyrolysate. The investigation revealed various groups of organic compounds such as heterocyclic compounds of nitrogen and simple and polycyclic aromatic hydrocarbons, while notable concentrations of compounds containing chlorine were detected as well. The experimental analysis found differences in the composition of amines and other compounds and in the dependence on grain size composition. Bulk samples produced the highest concentration of amines (˃ 40%) at a temperature of 500 °C. The sample homogenization led to a significant increase in amines production. Polyurethane waste of grain size from 0.125 to 0.25 mm contained approximately 80% amines. The pyrolysis of the bulk sample at 600 °C yielded only 24% nitrogen heterocyclic compounds, while from the sorted grain-size <0.045 mm and 0.045-0.063 mm, yields were increased to 47.4 and 45.7%, respectively.
Currently there is increasingly closer interaction between the importance of environmental protection and efficient promoting of scientific and technological progress in the field of waste incineration. Waste is not only undesirable source of pollution, but if it is effectively used it also has great economic importance. In the Czech Republic 34.5 million tonnes of all wastes was produced in 2017, of which 5.7 million tonnes of municipal waste. 50% of the produced municipal waste was used, 38% of which was used for the material and 12% for energy utilization. 45% of municipal waste was deposited in the landfills. The method of waste incineration is among the major tools to reduce the landfill waste. The use or processing of the product which the process of incineration of municipal and hazardous waste generated can be considered as an obstacle to the favorable reception of this process. Apart from flammable components, waste also contains certain amount of dangerous particles. This is especially the sulfur chlorides, fluorine, PCBs and other heavy decomposable organic substances and heavy metals. This fact puts high demands on the gas cleaning processes followed by neutralization of other products that the incinerator leaves, in which these substances can be contained in higher concentrations than in the original waste. For this reason subsequent stabilization of these toxic substances is necessary to ensure new environmental burdens are avoided when not used properly. The major part of the waste combustion process is made up of ash and slag. One of the most common ways of dealing with these solid residues is disposing them to avoid creating new hazardous waste landfills. Other filtering waste also passes hazardous waste stabilization process before landfilling. Currently there is intensive search for new possibilities for utilization of solid residues from incineration. Nowadays there is emphasis on process control of their pretreatment for the production of draft procedure with its management. Appropriate procedures may minimize the instances of improper use.
- MeSH
- nebezpečný odpad MeSH
- odpadky - odstraňování * MeSH
- popel uhelný MeSH
- skládková zařízení MeSH
- spalování odpadů MeSH
- těžké kovy * MeSH
- tuhý odpad MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Annually, a great amount of waste fats and oils not suitable for human consumption or which cannot be further treated are produced around the world. A potential way of utilizing this low-cost feedstock is its conversion into biodiesel. The majority of biodiesel production processes today are based on the utilization of inorganic alkali catalysts. However, it has been proved that an organic base - tetramethylammonium hydroxide - can be used as a very efficient transesterification catalyst. Furthermore, it can be employed for the esterification of free fatty acids - reducing even high free fatty acid contents to the required level in just one step. The work presented herein, is focused on biodiesel production from waste frying oils and animal fats using tetramethylammonium hydroxide at the pilot-plant level. The results showed that the process performance in the pilot unit - using methanol and TMAH as a catalyst, is comparable to the laboratory procedure, even when the biodiesel is produced from waste vegetable oils or animal fats with high free fatty acid content. The reaction conditions were set at: 1.5% w/w of TMAH, reaction temperature 65°C, the feedstock to methanol molar ratio to 1:6, and the reaction time to 120min. The conversion of triglycerides to FAME was approximately 98%. The cloud point of the biodiesel obtained from waste animal fat was also determined.
- MeSH
- biopaliva * MeSH
- esterifikace MeSH
- estery chemie MeSH
- katalýza MeSH
- kvartérní amoniové sloučeniny chemie MeSH
- kyseliny mastné neesterifikované MeSH
- mastné kyseliny chemie MeSH
- methanol MeSH
- odpadky - odstraňování metody MeSH
- oleje rostlin chemie MeSH
- oleje chemie MeSH
- průmyslový odpad MeSH
- teplota MeSH
- triglyceridy chemie MeSH
- tuky chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Bio-waste makes up almost half portion of municipal solid waste. The characterization of household bio-waste is important in determining the most appropriate treatment method. The differences in composition and parameters of bio-waste derived from urban settlement (U-bio-waste) and family houses (F-bio-waste) during the four climate seasons are described in this paper. Twelve components and 20 parameters for bio-waste were evaluated. The composition of U-bio-waste was almost steady over those seasons, unlike F-bio-waste. U-bio-waste was comprised mainly (58.2%) of fruit and vegetable debris. F-bio-waste was primarily made up of seasonal garden components. The amount of variation among seasons in both type of bio-waste increased in sequence: basic parameters
- MeSH
- biodegradace MeSH
- časové faktory MeSH
- charakteristiky rodiny MeSH
- látky znečišťující životní prostředí analýza klasifikace MeSH
- monitorování životního prostředí MeSH
- odpadky - odstraňování metody MeSH
- odpadní produkty analýza klasifikace MeSH
- ovoce MeSH
- roční období MeSH
- velkoměsta MeSH
- zelenina MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- velkoměsta MeSH
BACKGROUND: Barley straw, an agricultural by-product, can also serve as a low-cost and relatively efficient adsorbent of various harmful compounds. In this case, adsorption of four water-soluble dyes belonging to different dye classes (specifically Bismarck brown Y, representing the azo group; methylene blue, quinone-imine group; safranin O, safranin group; and crystal violet, triphenylmethane group) on native and citric acid-NaOH-modified barley straw, both in magnetic and non-magnetic versions, was studied. RESULTS: The adsorption was characterized using three adsorption models, namely Langmuir, Freundlich and Sips. To compare the maximum adsorption capacities (qmax), the Langmuir model was employed. The qmax values reached 86.5-124.3 mg of dye per g of native non-magnetic straw and 410.8-520.3 mg of dye per g of magnetic chemically modified straw. Performed characterization studies suggested that the substantial increase in qmax values after chemical modification could be caused by rougher surface of adsorbent (observed by scanning electron microscopy) and by the presence of higher amounts of carboxyl groups (detected by Fourier transform infrared spectroscopy). The adsorption processes followed the pseudo-second-order kinetic model and thermodynamic studies indicated spontaneous and endothermic adsorption. CONCLUSION: The chemical modification of barley straw led to a significant increase in maximum adsorption capacities for all tested dyes, while magnetic modification substantially facilitated the manipulation with adsorbent.
- MeSH
- adsorpce MeSH
- barvicí látky chemie MeSH
- biomasa MeSH
- chemické látky znečišťující vodu chemie MeSH
- ječmen (rod) chemie MeSH
- kinetika MeSH
- magnetismus * MeSH
- mikroskopie elektronová rastrovací MeSH
- průmyslový odpad MeSH
- stonky rostlin chemie MeSH
- termodynamika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Using random chemical mutagenesis we obtained the mutant of Cupriavidus necator H16 which was capable of improved (about 35 %) production of poly(3-hydroxybuytrate) (PHB) compared to the wild-type strain. The mutant exhibited significantly enhanced specific activities of enzymes involved in oxidative stress response such as malic enzyme, NADP-dependent isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase and glutamate dehydrogenase. Probably, due to the activation of these enzymes, we also observed an increase of NADPH/NADP⁺ ratio. It is likely that as a side effect of the increase of NADPH/NADP⁺ ratio the activity of PHB biosynthetic pathway was enhanced, which supported the accumulation of PHB. Furthermore, the mutant was also able to incorporate propionate into copolymer poly(3-hydroxybuytyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] more efficiently than the wild-type strain (Y3HV/prec = 0.17 and 0.29 for the wild-type strain and the mutant, respectively)). We assume that it may be caused by lower availability of oxaloacetate for the utilization of propionyl-CoA in 2-methylcitrate cycle due to increased action of malic enzyme. Therefore, propionyl-CoA was incorporated into copolymer rather than transformed to pyruvate via 2-methylcitrate cycle. Thus, the mutant was capable of the utilization of waste frying oils and the production of P(3HB-co-3HV) with better yields and improved content of 3HV resulting in better mechanical properties of copolymer than the wild-type strain. The results of this work may be used for the development of innovative fermentation strategies for the production of PHA and also it might help to define novel targets for the genetic manipulations of PHA producing bacteria.
- MeSH
- acylkoenzym A metabolismus MeSH
- bakteriální proteiny genetika metabolismus MeSH
- bioreaktory MeSH
- biosyntetické dráhy MeSH
- Brassica rapa MeSH
- Cupriavidus necator účinky léků genetika metabolismus MeSH
- fermentace MeSH
- hydroxybutyráty metabolismus MeSH
- mutageneze * MeSH
- oleje rostlin chemie metabolismus MeSH
- oxidační stres MeSH
- polyestery metabolismus MeSH
- polyhydroxyalkanoáty metabolismus MeSH
- průmyslový odpad MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hlavním cílem tohoto projektu bylo navrhnout a optimalizovat proces mikrobiální produkce kyseliny mléčné na modelovém MRS médiu za použití levného keratinového hydrolyzátu s cílem dosáhnout vysokého výtěžku a koncentrace kyseliny mléčné, produkované kmenem Lactobacillus casei 198. Nejprve bylo kuřecí peří zkoumáno jako levný zdroj dusíku. S ohledem na růst biomasy a konečnou koncentraci kyseliny mléčné, jako hlavního kritéria, byl pro další experimenty vybrán 20 % hydrolyzát kuřecího peří. Použití tohoto hydrolyzátu způsobilo minimální zředění celkového objemu kultivačního média v bioreaktoru. Konečná dosažená koncentrace kyseliny mléčné v médiu ze vsádkové kultivace byla 48 g/l. Bohužel, i když hydrolyzát peří vykazoval slibný výsledek jako neutralizační činidlo ve vsádkové kulti‑ vaci, tak se neprokázal jako vhodný zdroj dusíku v přítokované kultivaci, kde bylo dosaženo pouze 35 % koncentrace kyseliny mléčné ve srovnání s MRS médiem.
The main objective of this project was to design and optimize the process of microbial production of lactic acid on a model MRS medium using an inexpensive keratin hydrolysate with the goal to achieve high yield and concentration of lactic acid produced by the strain Lactobacillus casei 198. Firstly, the chicken feather was investigated as a low‑cost source of nitrogen. Taking the growth of biomass and the final concentration of lactic acid as the main criteria, 20 % hydrolysate of chicken feather was chosen for the next experiments. Using this hydrolysate caused minimal dilution of the total volume of the culture medium in the bioreactor. The final achieved concentration of lactic acid in the medium in batch culture was 48 g/L Unfortunately, although the feather hydrolysate showed promising result as a neutralizing agent in a batch culture, it was not suitable as a source of nitrogen in a fed‑batch culture, where only 35 % concentration of lactic acid was achieved compared to the MRS medium.
- MeSH
- chemické inženýrství metody MeSH
- kyselina mléčná * biosyntéza ekonomika MeSH
- nakládání s odpady MeSH
- Publikační typ
- práce podpořená grantem MeSH
Food waste collected exclusively from University restaurant was tested under anaerobic digestion (AD) conditions to determine its biomethane generation potential. The digestion characteristics of food waste were evaluated in BMP tests and in a conventional single-stage mesophilic CST Reactor. The suitability of psychrophilic two-stage AD to convert food waste was investigated by using a novel two-stage psychrophilic semi-continuous reactor, consisted of a vertically-oriented cylindrical reactor and a coaxially incorporated vertical tube able to spatially separate acidification from methanogenesis. Food waste presented significant methane generation performance under mesophilic conditions. Relatively high amounts of H2S released during process evolution did not have a significant effect on biogas production. For psychrophilic two-stage AD, H2S generated during start-up provoked reactor's instability only for a few days. The system was stable and operated at steady-state conditions over the course of the main AD. Higher amount of biogas was produced by the two-stage psychrophilic reactor (0.800 m3 kgVS-1) than the mesophilic single-stage system (0.751 m3 kgVS-1). However, the average methane quantities generated by the two systems were remarkably similar (0.444 and 0.440 m3 kgVS-1). Psychrophilic process was more efficient in utilizing higher proportions of volatile organics contained in substrate for methane generation than mesophilic operation. The low-temperature two-stage reactor was more energy-efficient than the mesophilic CSTR for digestion of food waste. Two-stage anaerobic digestion system operating under psychrophilic conditions might be an economically feasible option for efficiently digesting food waste.
- MeSH
- anaerobióza MeSH
- biopaliva MeSH
- bioreaktory * MeSH
- methan MeSH
- odpadky - odstraňování * MeSH
- potraviny MeSH
- Publikační typ
- časopisecké články MeSH
Vinasse, a recalcitrant waste of the ethanol industry was employed for the production of polyhydroxyalkanoate (PHA) by the extremely halophilic archaeon, Haloarcula marismortui in shake flasks. The PHA was recovered by osmotic lysis of the cells and subsequent purification by sodium hypochlorite and organic solvents. Through UV-vis spectroscopy, differential scanning calorimetry, Fourier transform infrared, and nuclear magnetic resonance spectroscopy, the PHA was found to have characteristics very similar to that of the standard polyhydroxybutyrate (PHB) from Sigma. Inhibitory effect of polyphenols contained in vinasse was assessed by a quick and reliable cup-plate agar-diffusion method. Raw vinasse (10%) was utilized leading to accumulation of 23% PHA (of cell dry weight) and following an efficacious pre-treatment process through adsorption on activated carbon, 100% pre-treated vinasse could be utilized leading to 30% accumulation of PHB by H. marismortui. Maximum specific growth rate, specific production rate, and volumetric productivity attained using 10% raw vinasse were comparable to that obtained using a previously reported nutrient deficient medium (NDM), while the values with 100% pre-treated vinasse were higher than that determined using NDM medium. This is the first report of polyhydroxybutyrate production by a halophilic microorganism utilizing vinasse.
The annual food and agricultural waste production reaches enormous numbers. Therefore, an increasing need to valorize produced wastes arises. Waste materials originating from the food and agricultural industry can be considered as functional materials with interesting properties and broad application potential. Moreover, using an appropriate magnetic modification, smart materials exhibiting a rapid response to an external magnetic field can be obtained. Such materials can be easily and selectively separated from desired environments. Magnetically responsive waste derivatives of biological origins have already been prepared and used as efficient biosorbents for the isolation and removal of both biologically active compounds and organic and inorganic pollutants and radionuclides, as biocompatible carriers for the immobilization of diverse types of (bio)molecules, cells, nano- and microparticles, or (bio)catalysts. Potential bactericidal, algicidal, or anti-biofilm properties of magnetic waste composites have also been tested. Furthermore, low cost and availability of waste biomaterials in larger amounts predetermine their utilization in large-scale processes.
