Microbiological and epizootological characterization of materials from wastewater treatment plant

Studies were carried out for the presence of microorganisms of major groups, containing pathogenic agents with epizootological importance, in order characteristic of their dynamics at different levels in the treatment plant and assessing the environmental safety of the final materials. For this purpose were traced the changes in the quantities of microorganisms contained in the materials from successive levels of processing. It was found that the purified water inlet and outlet does not contain Salmonella enterica. Presence of Escherichia coli and Clostridium perfringens beyond the requirements of the regulation (Decree N339, 2004) was not established, as well as Enterococcus spp. The tested sludge contained microorganisms from these groups and could not be deposited in the soil without prior aerobic or anaerobic processing. The draining in the nature of treated water at the outlet of plant does not hide environmental risk. In addition to monitoring of the sanitary indicative bacteria, the following of the main groups of Gram-negative and Gram-positive microorganisms in the water and sewage sludge allows more reliable assessment of their decontamination. Furthermore, the new approach for reporting the results in a unit of dry matter of the studied materials, proposed here, allows their more exact comparison

Reduction of sanitary indicator microorganisms in anaerobic digestion of poultry litter in combination with silages

ABSTRACT: In connection with experiments aimed at optimizing anaerobic digestion of organic fertilizers, microbiological tests were performed to assess the epizootiological safety of resulting finished product to fertilize the soil by quantities of sanitary indicator microorganisms. Mixtures of substrates were composed and tested in technological parameters established for other experiments: mesophilic temperature regime 33oC, dry matter content of 7%, residence time in the digester 15 days. The substrates tested were beetroot, sugar and salad beets, corn silage and leaves of Paulownia elongata, and silage combinations of these feeds in ratio 60:40 with mulch litter from broiler chickens. It was found that significant reduction of microorganisms was realized in the final products, which were assessed as safe for soil application. The ensiling of poultry litter in combinations of these feeds had the effect of reducing the amount of microorganisms in almost all examined groups therein. The most significant was the reduction in the quantity of sanitary revealing bacteria in the manure after its ensilage with autumn leaves of P. elongata and beetroot, and the least - with the participation of sugar beet. Microbial reduction was to the greatest extent in bioslime produced by anaerobic digestion of poultry litter ensiled with corn. Of the silages from different types of beets with poultry manure, during anaerobic digestion highest decontamination was achieved in this with sugar beets. After anaerobic degradation of the studied feed without poultry litter, at least microorganisms were found in bioslimes from the three types of beet, as well from the silage from P. elongata. РЕЗЮМЕ: Във връзка с експерименти, насочени към оптимизиране на анаеробното разграждане на органични торове, са извършени микробиологични изследвания за преценка на епизоотологичната безопасност на получените крайни продукти за наторяване на почви според количествата на санитарно индикаторните микроорганизми. Съставени са смеси от субстрати при установени при други експерименти технологични параметри: мезофилен температурен режим 33оС, съдържание на сухо вещество 7%, време на престой в биореактора 15 денонощия. Изпитани са захарно, кръмно и салатно цвекло, царевичен силаж и листа от Paulownia elongata, както и силажи от комбинации на тези фуражи в съотношение 60:40 с торова постеля от пилета-бройлери. Установено е, че се осъществява значително редуциране на микроорганизмите в крайните продукти, които се преценяват като безопасни за внасяне в почвите. В най-голяма степен микробната редукция е при биошлама, получен при анаеробното разграждане на комбинацията от торова постеля с царевичен силаж. От трите вида цвекло, силажирани с птичи тор, при анаеробно разграждане се постига най-висока деконтаминация с участие на захарното цвекло. При анаеробно разграждане на изследваните фуражи без птичи тор най-малко микроорганизми се установяват в биошламовете от трите вида цвекло, както и в силажа от P. elongata

Microbiological evaluation of sewage sludge in terms of possibility of applications in soil as a fertilizer

The studies were carried out of sewage sludge from wastewater treatment plant for the presence of microorganisms of several main groups, containing pathogenic representatives with epizootological significance (Gram-negative aerobic bacteria, E. coli, Clostridium perfringens, the genera Pseudomonas, Staphylococcus, Enterococcus, fungi, and the total number of microorganisms), in order to assess the environmental safety of the final product. In parallel similar studies were made of fresh and composted cattle manures. A comparison of the results was made with the ready for manuring compost in order to assess the possibilities for the use of sludge for fertilizing. The quantities of microorganisms were given in CFU per 1 g of the investigated material, as well as per 1 g of dry substance for each of them. In our opinion this new approach to the reporting of the results per unit of dry matter of the investigated materials, allows for a more accurate comparison. It was found that the examined sewage sludge from wastewater treatment plant were rich in microorganisms from studied groups and their direct application in soils without prior treatment by aerobic or anaerobic digestion may represent epidemiological danger

Expression of VEGFxxxb, the inhibitory isoforms of VEGF, in malignant melanoma

Malignant melanoma is the most lethal of the skin cancers and the UK incidence is rising faster than that of any other cancer. Angiogenesis – the growth of new vessels from preexisting vasculature – is an absolute requirement for tumour survival and progression beyond a few hundred microns in diameter. We previously described a class of anti-angiogenic isoforms of VEGF, VEGFxxxb, that inhibit tumour growth in animal models, and are downregulated in some cancers, but have not been investigated in melanoma. To determine whether VEGFxxxb expression was altered in melanoma, PCR and immunohistochemistry of archived human tumour samples were used. In normal epidermis and in a proportion of melanoma samples, VEGFxxxb staining was seen. Some melanomas had much weaker staining. Subsequent examination revealed that expression was significantly reduced in primary melanoma samples (both horizontal and vertical growth phases) from patients who subsequently developed tumour metastasis compared with those who did not (analysis of variance (ANOVA) P<0.001 metastatic vs nonmetastatic), irrespective of tumour thickness, while the surrounding epidermis showed no difference in expression. Staining for total VEGF expression showed staining in metastatic and nonmetastatic melanomas, and normal epidermis. An absence of VEGFxxxb expression appears to predict metastatic spread in patients with primary melanoma. These results suggest that there is a switch in splicing as part of the metastatic process, from anti-angiogenic to pro-angiogenic VEGF isoforms. This may form part of a wider metastatic splicing phenotype

Effect of Substrate Temperature on Structure, Morphology and Optical Properties of Sb2Se3 Thin Films Fabricated by Chemical-Molecular Beam Deposition Method from Sb and Se Precursors for Solar Cells

Sb2Se3 thin films were obtained by chemical-molecular beam deposition on soda-lime glass from high purity Sb and Se precursors at 400 ◦C, 450 ◦C and 500 ◦C substrate temperature. By the exact control of the Sb/Se ratio, Sb2Se3 thin films with stoichiometric composition were obtained. The effect of substrate temperature on morphology, structure and optical properties of Sb2Se3 thin-films were studied by energy-dispersive X-ray microanalysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy and atomic force microscopy. Average diameters and lengths of Sb2Se3 rods deposited at different substrate temperature were the range of 0.5÷2 μm and 1÷4 μm respectively which was grown at different slope and compactness to the substrate. The optical bandgap of the films was determined from the transmission and reflection spectra and 1.16, 1.21 and 1.26 eV band gap energies were observed for 500, 450 and 400 °C substrate temperature Sb2Se3 thin films respectively

Structural and optical properties of SbxSey thin films obtained by chemical molecular beam deposition method from Sb and Se precursors

SbxSey thin-films were obtained by chemical-molecular beam deposition (CMBD) on soda-lime glass from Sb and Se precursors. By the precise control of the Sb/Se ratio, Sb2Se3 thin films with stoichiometric composition were successfully obtained. The elemental and phase composition, as well as the crystal structure of SbxSey thin-films, were studied by energy-dispersive X-ray microanalysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy and atomic force microscopy. The optical bandgap of the films was determined from the absorption spectra acquired by a spectrophotometer. The physical properties of SbxSey thin films with different compositions were investigated

Structural and optical properties of {SbxSey} thin films obtained by chemical molecular beam deposition method from Sb and Se precursors

SbxSey thin-films were obtained by chemical-molecular beam deposition (CMBD) on soda-lime glass from Sb and Se precursors. By the precise control of the Sb/Se ratio, Sb2Se3 thin films with stoichiometric composition were successfully obtained. The elemental and phase composition, as well as the crystal structure of SbxSey thin-films, were studied by energy-dispersive X-ray microanalysis, X-ray diffraction, Raman spectroscopy, scanning electron microscopy and atomic force microscopy. The optical bandgap of the films was determined from the absorption spectra acquired by a spectrophotometer. The physical properties of SbxSey thin films with different compositions were investigated