digestate Dotaz Zobrazit nápovědu
The current commercial production of polyhydroxyalkanoates (PHA) is based on heterotrophic bacteria, using organic carbon sources from crops. To avoid the competition with food and feed production, cyanobacteria, metabolising PHA from carbon dioxide can be used. This research focuses on the investigation of the thermal and rheological properties of PHA polymers accumulated by Synechocystis salina, which had been cultivated in digestate supernatant and a mineral medium. The dried bacterial cells had a polymer content of 5.5-6.6%. The relevance of the derived PHA polymers for the common melt polymer processing was correlated with their molecular mass distribution as well as with their thermal and rheological properties. The determined thermal and rheological properties showed that PHA polymers accumulated by S. salina on digestate supernatant or mineral medium are comparable with the commercial available poly(3-hydroxybutyrate). However, the results showed that PHA polymers in general require modification before melt processing to increase their stability in the molten state.
The aim of this work was to prepare a softwood substrate on which to grow edible and medicinal mushrooms. Liquid digestate from a biogas station was successfully used in spruce sawdust fermentation. Pleurotus ostreatus, P. eryngii, and Ganoderma lucidum were grown on the obtained substrates and their mycelia grew at rates similar to rates of growth on control beech sawdust; values ranged from 4.1 to 5.54 mm/day. A 6-week fermentation period was determined to be sufficient for removing volatile extractives from sawdust (76% removal efficiency), which elevated content was shown to be most critical for fungal growth. Removal of 47% of resinous compounds and a decrease in the carbon-to-nitrogen ratio in the growth substrate were found during sawdust fermentation in the presence of the liquid digestate. Among ligninolytic enzymes, the growth substrates produced here favored laccase produced by tested fungi. It follows that utilizing wastes from biogas production to reuse softwood wastes could make an environmentally friendly and economically viable biotechnology for producing mushrooms.
Soil from Trhové Dušníky (Příbram, Czech Republic) is characterized by its high polymetallic accumulations in Pb-Ag-Zn due to mining and smelting activities. In previous studies performed in our research group, we have evaluated the potential use of amendments that would reduce the mobility and availability of metals such as Hg. We have observed that the application of digestate and fly ash in metal-polluted soil has an impact in immobilizing these metals. However, until now we have lacked information about the effect of these amendments on soil microbial functionality and communities. The multi-contaminated soil was used to grow wheat in a pot experiment to evaluate the impact of digestate and fly ash application in soil microbial communities. Soil samples were collected after 30 and 60 days of treatment. The digestate application improved chemical attributes such as the content in total organic carbon (TOC), water soluble carbon (WSOC), total soluble carbon (C), total soluble nitrogen (N), and inorganic N forms (NO3(-)) as consequence of high content in C and N which is contained in digestate. Likewise, microbial activity was greatly enhanced by digestate application, as was physiological diversity. Bacterial and fungal communities were increased, and the microbial biomass was highly enhanced. These effects were evident after 30 and 60 days of treatment. In contrast, fly ash did not have a remarkable effect when compared to digestate, but soil microbial biomass was positively affected as a consequence of macro- and micro-nutrient sources applied by the addition of fly ash. This study indicates that digestate can be used successfully in the remediation of metal-contaminated soil.
- MeSH
- biomasa MeSH
- dusík analýza MeSH
- hornictví MeSH
- houby fyziologie MeSH
- kovy analýza metabolismus MeSH
- látky znečišťující půdu analýza metabolismus MeSH
- mikrobiální společenstva MeSH
- popel uhelný * MeSH
- pšenice růst a vývoj MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- rtuť analýza metabolismus MeSH
- uhlík analýza chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Concentration of trace metals (TMs) is one of the most crucial factors determining the quality of cereal grains. The aim of this study was to evaluate the effect of digestate, manure, and NPK fertilization on TM concentration in grains and straw of two cereal crops-winter wheat (WW) and spring barley (SB)-and TM transfer from soil to plants. The experiment was carried out between 2012 and 2016. Every year, the same treatment was used on each plot: control (without fertilization), digestate, digestate + straw, cattle slurry, and mineral NPK fertilization. In general, fertilization increased the concentration of TMs that belong to the micronutrient group (Zn, Cu, Fe), particularly after application of digestate and cattle slurry. At the same time, fertilization, regardless of the fertilizer type, led to an increase in Cd concentration in the grain of WW in comparison with the control. Despite the increase in Cd and micronutrient content as a result of fertilization, the concentration of elements remained below the applicable standards. Among TMs, only Pb content exceeded the European Union limits. The increased concentration of Pb was, however, an effect of other factors, rather than fertilization. The results clearly indicated that the biogas digestate from anaerobic codigestion of cattle slurry and agricultural residue could be utilized as fertilizer in agricultural applications without a risk of contaminating the food chain with TMs.
- MeSH
- hnůj MeSH
- ječmen (rod) * metabolismus MeSH
- kovy chemie MeSH
- minerály chemie metabolismus MeSH
- průmyslová hnojiva * MeSH
- pšenice metabolismus MeSH
- půda MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Large production of liquid phase of digestate (LPD) characterised by low dry matter content increases the costs of LPD storage and transportation. Additionally, significant nitrogen losses result from LPD handling. The operation of biogas plants also requires large amounts of technological water, a scarce resource. The method of LPD nitrification and subsequent thermal thickening as a promising alternative treatment able to overcome those problems was investigated. The properties of thermally thickened nitrified LPD and of the distillate derived from vacuum evaporation of nitrified LPD were examined. The results show that over 99.9% of nitrogen was accumulated in thickened nitrified LPD. Total nitrogen (TN) concentration in thickened LPD ranged from 12 to 18 g/L depending on the distillate/thickened LPD volume ratio applied. The thickened LPD was also richer in other nutrients, which indicates its possible use as a concentrated complex fertiliser. TN concentration and conductivity in the distillate did not exceed 6 mg/L and 0.03 mS/m respectively, suggesting that the distillate may be useful as alternative source of technological water. It was concluded that the system consisting of nitrification and subsequent thermal thickening of nitrified LPD yields final products exhibiting significantly superior properties compared to thermal thickening of raw LPD, without requiring any additional chemical agents. The quality of these products is comparable to those obtained through advanced membrane processes.
- MeSH
- biopaliva MeSH
- dusík analýza MeSH
- nitrifikace MeSH
- průmyslová hnojiva * MeSH
- voda * MeSH
- Publikační typ
- časopisecké články MeSH
The nitrification of the liquid phase of digestate (LPD) was conducted using a 5L completely stirred tank reactor (CSTR) in two independent periods (P1 - without pH control; P2 - with pH control). The possibility of minimizing nitrogen losses during the application of LPD to the soil as well as during long-term storage or thermal thickening of LPD using nitrification was discussed. Moreover, the feasibility of applying the nitrification of LPD to the production of electron acceptors for biological desulfurization of biogas was assessed. Despite an extremely high average concentration of ammonia and COD in LPD reaching 2470 and 9080mg/L, respectively, nitrification was confirmed immediately after the start-up of the CSTR. N-NO3-concentration reached 250mg/L only two days after the start of P1. On the other hand, P1 demonstrated that working without pH control is a risk because of the free nitrous acid (FNA) inhibition towards nitrite oxidizing bacteria (NOB) resulting in massive nitrite accumulation. Up to 30.9mg/L of FNA was present in the reactor during P1, where the NOB started to be inhibited even at 0.15mg/L of FNA. During P2, the control of pH at 7.0 resulted in nitrogen oxidation efficiency reaching 98.3±1.5% and the presence of N-NO3-among oxidized nitrogen 99.6±0.4%. The representation of volatile free ammonia within total nitrogen was reduced more than 1000 times comparing with raw LPD under these conditions. Thus, optimum characteristics of the tested system from the point of view of minimizing the nitrogen losses as well as production of electron acceptors for the desulfurization of biogas were gained in this phase of reactor operation. Based on the results of the experiments, potential improvements and modifications of the tested system were suggested.
- MeSH
- amoniak MeSH
- bioreaktory * MeSH
- dusík MeSH
- dusitany MeSH
- nitrifikace * MeSH
- Publikační typ
- časopisecké články MeSH
Zažívací potíže diabetiků představují závažný problém. Předkládané sdělení shrnuje poznatky o symptomatologii, diagnostice a léčbě zažívacích potíží z pohledu diabetologa.
Digestive troubles in diabetics present a serious problem. The article summarizes knowledge of their symptomatology, diagnosis and treatment from the point of view of a diabetologist.
- MeSH
- autonomní nervový systém patofyziologie MeSH
- diabetické neuropatie diagnóza komplikace terapie MeSH
- diagnostické techniky gastrointestinální MeSH
- diferenciální diagnóza MeSH
- farmakoterapie metody normy MeSH
- gastrointestinální motilita MeSH
- lidé MeSH
- příznaky a symptomy ústrojí trávicího diagnóza etiologie terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Krvácení do horní části trávicí trubice je bohužel stále aktuálním problémem. Krvácení může pocházet z různých etáží trávicí trubice a z různých zdrojů. Může mít formu zjevnou i dramatickou, ale může být i plíživé, okultní.
Haemorrhage in the upper digestive tract unfortunately remains a pressing problem. The haemorrhage can originate in various parts of the digestive tract and its sources can be varied as well. It can be apparent or even dramatic, or sneaky, occult.
- Klíčová slova
- horní část,
- MeSH
- diagnostické techniky gastrointestinální MeSH
- endoskopie trávicího systému * ošetřování MeSH
- gastrointestinální krvácení * diagnóza etiologie klasifikace komplikace krev patologie prevence a kontrola terapie MeSH
- gastrointestinální trakt anatomie a histologie patologie MeSH
- krvácení MeSH
- lidé MeSH
- rizikové faktory MeSH
- Check Tag
- lidé MeSH
Digestivní endoskopií lze v současné době vyšetřit celý gastrointestinální trakt. Na bázi původně čistě diagnostických procedur se v průběhu let vyvinula řada terapeutických modalit, které v některých indikacích nahradily chirurgickou léčbu a metody invazivní radiologie. Nejvýznamnější jsou metody endoskopické resekce a ablace určené k léčbě časných neoplazií trávicí trubice, které nejsou provázeny významným rizikem lymfatické a systémové diseminace. Mezi resekční metody patří endoskopická polypektomie, endoskopická mukózní resekce, endoskopická submukózní disekce a endoskopická transmurální resekce. Z ablačních metod je v klinické praxi běžně užívána radiofrekvenční ablace v léčbě dysplastického Barrettova jícnu a argonová plazmakoagulace užívaná v léčbě symptomatických cévních malformací a drobných lokálních reziduálních neoplazií.
Digestive endoscopy today is able to examine the whole gastrointestinal tract. On the basis of the originally purely diagnostic procedures a range of therapeutic modalities has been developed over years, which in some indications have taken the place of surgical procedures and methods of invasive radiology. Of greatest importance are the methods of endoscopic resection and ablation designed for the treatment of early neoplasms of the digestive tract not accompanied by a significant risk of lymphatic and systemic dissemination. Resection methods include endoscopic polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic transmural resection. Regarding ablation methods, commonly used in clinical practice are radiofrequency ablations in the treatment of dysplasia in Barretts esophagus and argon plasma coagulation used in the treatment of symptomatic vascular malformations and small local residual neoplasms.
- Klíčová slova
- endoskopická polypektomie, endoskopická resekce, endoskopická transmurální resekce,
- MeSH
- endoskopická mukózní resekce metody MeSH
- endoskopie trávicího systému * metody MeSH
- gastrointestinální endoskopie metody MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
