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The effect of bed properties on methane removal in an aerated biofilter--model studies 总被引:1,自引:0,他引:1
The capacity of laboratory-scale aerated biofilters to oxidize methane was investigated. Four types of organic and mineral-organic materials were flushed with a mixture of CH4, CO2 and air (1:1:8 by volume) during a six-month period. The filter bed materials were as follows: (1) municipal waste compost, (2) an organic horticultural substrate, (3) a composite of expanded perlite and compost amended with zeolite, and (4) the same mixture of perlite and compost amended with bentonite. Methanotrophic capacity during the six months of the experiment reached maximum values of between 889 and 1036 g m−2 d−1. Batch incubation tests were carried out in order to determine the influence of methane and oxygen concentrations, as well as the addition of sewage sludge, on methanotrophic activity. Michaelis constants KM for CH4 and O2 were 4.6-14.9%, and 0.7-12.3%, respectively. Maximum methanotrophic activities Vmax were between 1.3 and 11.6 cm3 g−1 d−1. The activity significantly increased when sewage sludge was added. The main conclusion is that the type of filter bed material (differing significantly in organic matter content, water-holding capacity, or gas diffusion coefficient) was not an important factor in determining methanotrophic capacity when oxygen was supplied to the biofilter. 相似文献
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Marek Roszko Krystyna Szymczyk Renata Jędrzejczak 《Journal of environmental science and health. Part. B》2013,48(12):884-895
The aim of this study was to evaluate effects of food processing on PBDE levels, in particular influence of heat treatment on degradation of PBDEs, including possible formation of chlorinated diphenyl ethers or brominated dioxins/furans as degradation products. It was shown that PBDEs heated in the presence of chlorine (from either organic or inorganic sources) formed mixed chlorinated/brominated diphenyl ethers. However, no PCDEs were formed in the presence of lipids. Lipid medium increased stability of PBDEs exposed to UV irradiation. Profile of congeners formed in result of the debromination reaction was significantly different than profiles observed by some other authors in aliphatic organic solvents. Grilling processes increased concentrations (calculated on the fresh product basis) of the studied compounds by 4–8/22–34% for electric/coal grill, respectively. Depending on the congener and on the applied heat treatment, PBDE mass in pork meat after grilling dropped by 26–53%. No detectable quantities of either brominated dioxins or furans were formed during thermal processing of food containing typical levels of PBDEs. 相似文献
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Beata Gutarowska Łukasz Stępień Bogumiła Szponar Anna Otlewska Katarzyna Pielech-Przybylska 《Journal of the Air & Waste Management Association (1995)》2013,63(4):466-478
The objective of the study was to determine the degree of microbiological contamination, type of microflora, bioaerosol particle size distribution, and concentration of endotoxins in dust in different types of composting plants. In addition, this study provides a list of indicator microorganisms that pose a biological threat in composting facilities, based on their prevalence within the workplace, source of isolation, and health hazards. We undertook microbiological analysis of the air, work surfaces, and compost, and assessed the particle size distribution of bioaerosols using a six-stage Andersen sampler. Endotoxins were determined using gas chromatography–mass spectrometry (GC-MS). Microbial identification was undertaken both microscopically and using biochemical tests. The predominant bacterial and fungal species were identified using 16S rRNA and ITS1/2 analysis, respectively.?The number of mesophilic microorganisms in composting plants amounted to 6.9 × 102–2.5 × 104 CFU/m3 in the air, 2.9 × 102–3.3 × 103 CFU/100 cm2 on surfaces, and 2.2 × 105–2.4 × 107 CFU/g in compost. Qualitative analysis revealed 75 microbial strains in composting plants, with filamentous fungi being the largest group of microorganisms, accounting for as many as 38 isolates. The total amount of endotoxins was 0.0062–0.0140 nmol/mg of dust. The dust fraction with aerodynamic particle diameter of 0.65–1.1 μm accounted for 28–39% of bacterial aerosols and 4–13% of fungal aerosols. We propose the following strains as indicators of harmful biological agent contamination: Bacillus cereus, Aspergillus fumigatus, Cladosporium cladosporioides, C. herbarum, Mucor hiemalis, and Rhizopus oryzae for both types of composting plants, and Bacillus pumilus, Mucor fragilis, Penicillium svalbardense, and P. crustosum for green waste composting plants. The biological hazards posed within these plants are due to the presence of potentially pathogenic microorganisms and the inhalation of respirable bioaerosol. Depending on the type of microorganism, these hazards may be aggravated or reduced after cleaning procedures.Implications:?This study assessed the microbial contamination in two categories of composting plants: (1) facilities producing substrates for industrial cultivation of button mushrooms, and (2) facilities for processing biodegradable waste. Both workplaces showed potentially pathogenic microorganisms, respirable bioaerosol, and endotoxin. These results are useful to determine the procedures to control harmful biological agents, and to disinfect workplaces in composting plants. 相似文献
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Marcin Dębowski Marcin Zieliński Anna Grala 《International Journal of Green Energy》2016,13(4):395-407
This study was aimed at establishing the feasibility of microalgae biomass acquisition from waters of the Vistula Lagoon with the use of an installation operating in the fractional–technical scale, and at determining the effectiveness of biogas production from the acquired substrate. Depending on the technological solution of the concentration process, the degree of aquatic biomass hydration ranged from 99.6 to 97.90%. The quantity of biogas produced during methane fermentation fitted within the range of 243.9 to 395.2 dm3/kg d.m.. The values achieved were found to depend directly on the concentration of organic matter in the acquired water biomass and on system’s loading with a feedstock of organic compounds. The content of methane in a gaseous mixture ranged from 41.4 to 61.9%. The biomass produced was predominated by taxa belonging to Cyanoprokaryota, Bacillarophyceae, and Chlorophyta. 相似文献
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Szulińska Elżbieta Zakrzewski Dorian Kafel Alina Gospodarek Janina Rozpędek Katarzyna Zawisza-Raszka Agnieszka 《Environmental science and pollution research international》2022,29(58):87218-87230
Environmental Science and Pollution Research - Here, we investigated whether the widely distributed snail Cepaea nemoralis could be used as a suitable sentinel animal for assessing the effects of... 相似文献
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Krzysztof Kosała Bartłomiej Stępień 《International journal of occupational safety and ergonomics》2016,22(1):92-101
This paper presents the verification of two partial indices proposed for the evaluation of continuous and impulse noise pollution in quarries. These indices, together with the sound power of machines index and the noise hazard index at the workstation, are components of the global index of assessment of noise hazard in the working environment of a quarry. This paper shows the results of acoustic tests carried out in an andesite quarry. Noise generated by machines and from performed blasting works was investigated. On the basis of acoustic measurements carried out in real conditions, the sound power levels of machines and the phenomenon of explosion were determined and, based on the results, three-dimensional models of acoustic noise propagation in the quarry were developed. To assess the degree of noise pollution in the area of the quarry, the continuous and impulse noise indices were used. 相似文献
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We demonstrate that carbon, hydrogen and sulphur isotope ratios both, in the total peat (13Ctp=–25.52 to –28.27, Dtp=–78.67 and –109.24, 34S=4.35 to 19.87), and in cellulose from the peat (13Cnc=–25.06 to –27.33 and Dnc=–92.43 to –118.02) are not affected by postdepositional changes. Therefore, the original isotope composition of plants are in general preserved in the peat and represent an archive of the past environmental variations. These can be supported by (i) good correlations between 13Ctp and 13Cnc, and between Dtp and Dnc, (ii) high horizontal homogeneity of 13Ctp and 13Cnc in the scale of one peat-bog – the same major factor(s) control(s) C isotopic ratios, (iii) no correlation between organic sulphur concentrations and 34S value –34S results from variations in the water level.This revised version was published online January 2005 with corrections to the title. 相似文献
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An analogue of insect oostatic peptide, the pentapeptide H-Tyr-Asp-Pro-Ala-Pro-OH (H-YDPAP-OH), was administered to female mice and its effects on reproduction and development of the ovaries were studied. Up to 0.5 mg of the peptide per mice (25 g b.w.) injected intraperitoneally did not change the rate of pregnancy, number of offsprings and histological findings in ovaries and uterus in comparison to saline treated controls. 相似文献