共查询到20条相似文献,搜索用时 31 毫秒
1.
The edible mushroomAgaricus bisporus is grown commercially on composted manure/straw mixtures. However, this proven composting procedure is wasteful of raw materials. A nonmanure compost was developed (Smith, 1980) with two main aims:
- To conserve raw materials, while still producing a compost favoringAgaricus bisporus colonization and giving an economic yield of mushrooms.
- To speed up composting, hence making more efficient use of labor, farm equipment, and buildings.
2.
A maturity sensor system was developed, based on the combination of three electrically measured parameters, pH, NH4+ concentration, and phosphatase activity in the water extracts of compost samples. One of these parameters, the apparent phosphatase activity in crude test solutions was determined using screen-printed carbon strips (SPCSs) coated with α-naphthyl phosphate (α-NP) in Nafion film. The phosphatase activity was monitored in connection with differential pulse voltammetry (DPV) with an aliquot (30 μL) of the test solution on SPCS. The phosphatase activity sensor was validated using alkaline phosphatase (ALP) in Tris-HCl buffer (pH 8.0) and acid phosphatase (ACP) in citric acid buffer (pH 5.0). The activity of the spiked enzymes in the water extract of the compost sample could be confirmed with the change of corresponding oxidation peak current signal of the product, α-naphthol. The water extracts of compost samples (n = 24) collected in various composting days were applied to our compost maturity sensor system, and the conventional germination tests. Using multiple regression analysis, the germination index (GI) was expressed by the multi-linear regression equation consisting of pH, NH4+ concentration, and the phosphatase activity. The calculated GI from the regression equation had a good correlation with the measured GI of the corresponding composts (r = 0.873). As a result, we have determined an equation for the determination of the compost stability using our portable sensor system rapidly at the composting site. 相似文献
3.
Eleftheria Katechaki Theodoros Solomonidis Argyro Bekatorou Athanasios A. Koutinas 《Applied biochemistry and biotechnology》2010,162(5):1270-1285
Lactobacillus bulgaricus grown on whey was dried by a simple thermal drying method at the range 35–55°C and its efficiency for lactic acid fermentation
of whey was evaluated. Drying of cells in whey suspension in the examined temperature range did not affect significantly their
viability (82–87% survival), indicating a protective effect of whey as both growth and drying medium. The kinetics of fermentation
of whey and mixtures of whey/molasses using the dried culture were comparable to those of non-dried cells, and only low pH
had a detrimental effect on the fermentation ability of the dried cells. Furthermore, dried L. bulgaricus, free or immobilized on casein coagulates, was used as starter for the production of unsalted hard-type cheese. The effects
of the amount of starter culture and the immobilization technique, the evolution of microbial counts, and the sensory properties
of the produced cheeses were evaluated during ripening at various temperatures. 相似文献
4.
Thitisilp Kijchavengkul Maria Rubino Mathieu Ngouajio 《Polymer Degradation and Stability》2010,95(12):2641-2647
The biodegradation and hydrolysis rates of an aliphatic aromatic copolyester were measured in manure, food, and yard compost environments and in phosphate buffer solution (pH = 8.0) and vermiculite at 58 °C. Mineralization, molecular weight reduction, and structural changes determined by DSC, FTIR, and 1H NMR were used as indicators of the biodegradation and hydrolysis rates. Poly(butylene adipate-co-terephthalate), PBAT, film biodegraded at distinctive rates in manure, food, and yard compost environments having different microbial activities. The highest biodegradation rate was found in manure compost, which had the highest CO2 emissions and lowest C/N ratio. The possible presence of extracellular enzymes in manure and food composts may facilitate the hydrolytic reaction since greater molecular weight reduction rates were observed in these composts. 1H NMR and thermal analysis revealed that, while PBAT is a semi-crystalline copolyester with cocrystallization of BT and BA dimers, the soft aliphatic domain (BA) and the amorphous region are more susceptible to hydrolysis and biodegradation than the rigid aromatic domain (BT) and the crystalline region. 相似文献
5.
Yabin Zhang Changfa Xiao Shulin An Jianfeng Yang 《Journal of Sol-Gel Science and Technology》2011,57(2):142-148
Morphologies of aluminosilicate gel fiber and mullite long fiber prepared from spinning sol of Al(NO3)3·9H2O, tetraethylorthosilicate and ethanol using polyvinyl butyral as a spinning aids have been studied experimentally. The weight
loss of fibers as function of drying time and calcination temperature was summarized and the fiber morphologies at different
temperature were also discussed. The results indicated that fiber sample lost the main weight at the first several minutes
at 40°C. A main axial crack was observed due to the heat stress if gel fiber was not pre-dried before calcination. Accompanied
by weight loss during heat treatment, “black” fibers were shown at the temperature range of 300–500°C and some attachment
was observed among fiber surface attributed by the decomposition of organic materials. The actual elimination temperature
of organic materials was different from our former heat analysis measurement result, and it could be explained by the pre-treating
procedure and high heating rate of heat analysis. The morphological study of mullite fiber calcined at different temperature
could help to understand and obtain the mullite fiber with smooth surface. 相似文献
6.
The effectiveness of in-vessel thermophilic composting on the inactivation of Botrytis cinerea was evaluated. The bioreactor operated on an infected mixture of tomato plant residues, wood shavings, and municipal solid
compost (1∶1.5∶0.28). Tap water and urea were added to adjust the moisture content and C∶N ratio to 60% and 30∶1, respectively.
Used cooking oil was added as a bioavailable carbon source to compensate for heat losses from the system and extend the thermophilic
compositing stage. The controlled thermophilic composting process was successful in inactivating B. cinerea. During all experiments, the average reactor temperature increased gradually, reaching its peak after 31 h of operation.
Temperatures in the range of 62.6–63.9°C were maintained during the thermophilic stage by the intermittent addition of used
cooking oil. The results of the enzyme-linked immunosorbent assay test indicated that the initial concentration of B. cinerea in the compost samples (14.6 μg of dried mycelium/g of compost) was reduced to 12.9, 8.8, and 2.4 μg/g after 24, 48, and
72 h of thermophilic composting, respectively. Plating assay indicated that the mold was completely inactivated in samples
after 48 h of thermophilic composting. No significant reduction in B. cinerea was observed during the transient phase (first 30 h of rising temperature) because the temperature reached the lethal level
of 55°C after 23 h, thus allowing only 7 h of exposure to temperatures higher than 55°C during this phase. The relatively
short time required for complete inactivation of B. cinerea was achieved by maintaining a constant high temperature and a uniform distribution of temperature and extending the duration
of the thermophilic stage by the addition of the proper amount of bioavailable carbon (used cooking oil). 相似文献
7.
The compostability of LDPE, PP and heterophasic E-P Copolymers was studied for 5 months under normal and accelerated composting environments. Bio-susceptibility of pre-UV (290 nm) treated films (∼ 100μm, 5 X 5 cm) was measured by monitoring the weight loss, intrinsic viscosity [η], chain scission, functional group evolution (FT-IR) and surface morphology (SEM). It was found that with the increasing time of UV treatment, weight loss was increased in compost. Almost linear decrease in [η] was observed for irradiated and composted samples. The temperature of compost and extra addition of thermophilic microbes significantly influenced the biodegradation. In general, it was concluded that the composition of copolymer markedly affected the compostability and increased ethylene content, slowed down the microbial activity. 相似文献
8.
Characterization of Compost with Respect to its Content of Heavy Metals. Part II: Sample Preparation
J. W. A. Lustenhouwer J. A. Hin F. J. M. J. Maessen G. Den Boef 《International journal of environmental analytical chemistry》2013,93(4):391-400
Abstract This paper forms part of a study aimed at the development of a procedure for the determination of heavy metals in compost. The present paper deals with the sample preparation stage, including subdividing laboratory samples and reduction of the particle size. The effect of particle size reduction on the random error due to the analysis of test portions was examined. It was found that milling for 20min in a quartz planet ball mill yields sufficiently homogeneous test samples. As the milling capacity of this device is too small, prior to milling subdivision of the laboratory sample is required. Subdivision before drying is recommended for practical reasons. 相似文献
9.
Poly(lactic) acid (PLA) is a compostable biopolymer and has been commercialised for the for the manufacture of short-shelf life products. As a result, increasing amounts of PLA are entering waste management systems and the environment; however, the degradation mechanism is unclear. While hydrolysis of the polymer occurs abiotically at elevated temperature in the presence of water, potential catalytic role for microbes in this process is yet to be established. In this study, we examined the degradation of PLA coupons from commercial packaging at a range of temperatures (25°, 37°, 45°, 50° and 55 °C) in soil and compost and compared with the degradation rates in sterile aqueous conditions by measuring loss of tensile strength and molecular weight (Mw). In addition, in order to assess the possible influence of abiotic soluble factors in compost and soil on degradation of PLA, degradation rates in microorganism-rich compost and soil were compared with sterile compost and soil extract at 50 °C. Temperature was determined to be the key parameter in PLA degradation and degradation rates in microorganism-rich compost and soil were faster than in sterile water at temperatures 45° and 50 °C determined by tensile strength and Mw loss. Furthermore, all tensile strength was lost faster after 30 and 36 days in microorganism-rich compost and soil, respectively, than in sterile compost and soil extract, 57 and 54 days, respectively at 50 °C. Significantly more Mw, 68% and 64%, was lost in compost and soil, respectively than in compost extract, Mw, 53%; and in soil extract, 57%. Therefore, degradation rates were faster in microorganism-rich compost and soil than in sterile compost and soil extract, which contained the abiotic soluble factors of compost and soil at 50 °C. These comparative studies support a direct role for microorganisms in PLA degradation at elevated temperatures in humid environments. No change in tensile strength or Mw was observed either 25° or 37 °C after 1 year suggesting that accumulation of PLA in the environment may cause future pollution issues. 相似文献
10.
Hye-Jeong Yun Sang-Yong Lim Hyun-Pa Song Byung-Keun Kim Byung-Yeoup Chung Dong-Ho Kim 《Radiation Physics and Chemistry》2007,76(11-12):1843-1846
Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm products because most of the composts are originated from excremental matters of domestic animals. In this study, the radiation treatment was performed to improve microbiological safety of organic compost and the effectiveness of gamma irradiation for inactivating Salmonella Typhimurium and Escherichia coli was investigated. The total aerobic and coliform bacteria in the 16 commercial composts were ranged from 105 to 107 CFU/ml and 0 to 103 CFU/ml, respectively. All coliform bacteria in the composts were eliminated by irradiation at a dose of 3 kGy, while about 102 CFU/ml of the total aerobic bacteria were survived up to 10 kGy. In the artificial inoculation test, the test organisms (inoculated at 107 CFU/g) were eliminated by irradiation at 3 kGy. Approximate D10 values of Salmonella Typhimurium and E. coli in the compost were 0.40 and 0.25 kGy, respectively. In the cultivation test, the test organisms of the compost had transfer a lettuce leaves. The growth pattern of lettuce was not different between irradiated and non-irradiated composts. 相似文献
11.
Telmo Ojeda Emilene Dalmolin Leonardo Vignol Rodrigo Jacques Flávio Camargo 《Polymer Degradation and Stability》2009,94(12):2128-2133
An alternative for improving the degradability of polyolefins and polystyrene is the addition of pro-oxidant substances to their formulations. The materials obtained are then called oxo-biodegradable. This work aimed to assess the biotic and abiotic degradation of atactic polystyrene (PS), utilising as test material foamed PS plates used in the manufacture of trays, formulated with Co- and Mn-based pro-oxidant additives. The plates were exposed to artificial weathering (ultraviolet radiation and heat) and were periodically analysed for changes in structural properties. The oxidised surface residues detached from the samples were incubated in a stabilised compost of urban waste (58 °C) or in an aqueous mineral medium (25 °C), the latter being inoculated with urban waste compost and also with a microbial consortium. It was found that the molar masses of the eroded materials from the pro-oxidant activated samples were significantly lower than the initial sample molar masses, with simultaneous incorporation of oxygen into the chains during the accelerated weathering. These samples underwent biodegradation and gave mineralisation values of 2-5% over 2-3 months of incubation in compost and perlite or in mineral aqueous medium. Biodegradation of the residues from the samples not containing pro-oxidant additives was also observed, but at levels which were lower than those obtained for oxo-biodegradable samples. 相似文献
12.
Brunori C Cremisini C D'Annibale L Massanisso P Pinto V 《Analytical and bioanalytical chemistry》2005,381(7):1347-1354
The effect of adding treated red mud, a by-product of alumina production, to soil polluted by an abandoned mine and characterised by high concentrations of heavy metals, relatively low reaction grade, and low organic carbon content, was investigated. Also studied was addition of both red mud and compost (produced from source-separated municipal solid waste)—the synergistic action of red mud and compost could be exploited to achieve both metal trapping and an increase in organic carbon content. Leaching batch tests were performed on four different systems: soil, soil and treated red mud, soil and compost, soil and compost plus treated red mud. Dilute sulfuric acid and EDTA solution (liquid/solid ratio 10:1) were used in the tests—sulfuric acid to mimic acid rain and EDTA in accordance with general methods for estimating plant-available metals. Sequential extraction was also applied to the same samples. The use of relatively non-specific extractant reagents in the leaching tests led to a kinetic approach (already proposed in literature), because measurements of trace elements extracted at equilibrium cannot be related to their speciation. Comparison of information obtainable by the kinetic approach to evaluation of data from leaching tests with results from sequential extraction enabled evaluation whether the kinetic fractionation method, a relatively rapid and simple procedure, furnishes adequate information about the mobility and bioavailability of trace elements. Especially interesting results were obtained for Mn, Zn, and Ni, present in large amounts in the soil studied—their leachability was significantly reduced by addition of red mud and compost, suggesting interesting perspectives in soil-remediation activity. 相似文献
13.
L. Nuñez-Regueira N. Barros I. Barja 《Journal of Thermal Analysis and Calorimetry》1994,41(6):1379-1383
The effect of the storage of soils on their microbial activity has been studied using a microcalorimetric method. Soil samples were kept in closed polyethene bags at 4°C during 3–6 months. Results show changes in the slope of the differentP?t curves recorded from the samples stored at 4°C. This fact strongly suggest the existence of changes of the microbial activity of soil as the heat evolution is a direct measurement of the cells metabolic activity. The value of the Peak-time (time in which the microcalorimetric signal reaches the maximum value) is related with the microbial density of soil samples. This parameter was affected by the time of storage increasing with time. The total heat evolutionQ(t), of the soil samples amended with glucose calculated from the area limited by the Power-Time curves, also decreases with the time of storage. The soil that had been stored for 6 months before experiments, showed the lowest valu ofQ(t). 相似文献
14.
J. M. Lynch S. H. T. Harper S. J. Chapman D. A. Veal 《Applied biochemistry and biotechnology》1984,9(4):379-380
Production of composts on the farm from surplus straw might provide a low-cost biotechnological approach for increasing the
value of this lignocellulosic waste. Successful composting depends on the conversion of the polysaccharides (cellulose and
hemicelluloses) of straw by inoculated microorganisms to products that can promote plant growth when applied to the land.
None of the potentially useful products we have identified are produced by cellulolytic organisms. We have therefore studied
mixed populations in which noncellulolytic bacteria depend for growth on the products of fungal cellulolysis. The nature and
yield of bacterial products depends not only on conditions within the compost, but also on the microbial inoculants used.
Under defined laboratory conditions, using pure cellulose, N2 is fixed by the anaerobic bacteriumClostridium butyricum in association with a cellulolytic fungus such asTrichoderma sp. A similar association has been achieved on straw withPenicillium corylophilum as the cellulolytic fungus.
Cellulolytic fungi can also provide available substrates for the production of bacterial polysaccharides that can improve
the structure of unstable soils. The yield of polysaccharide and its efficacy in soil aggregate stabilization again varies
with the inoculants used.
Such composts can thus contribute to plant nutrition and to soil structure. The adoption ofTrichoderma spp. as the cellulolytic inoculants would further extend the potential value of the compost to include the biocontrol of
plant pathogens. 相似文献
15.
Evaluation of the aerobic composting process of winery and distillery residues by thermal methods 总被引:1,自引:0,他引:1
F.C. Marhuenda-Egea E. Martínez-Sabater A. Sánchez-Sánchez M.A. Bustamante M.D. Pérez-Murcia 《Thermochimica Acta》2007,454(2):135-143
The possibility of using thermal analysis for a quick characterization of chemical changes was tested in the organic matter from composting materials. Differential thermal analysis (DTA), thermogravimetry (TG) and the first derivative of the TG (DTG) were calculated in oxidizing conditions on compost samples obtained from three composting piles. The composting piles were made by mixing winery and distillery residues with sewage sludge (pile 1), with cow manure (pile 2) and hen droppings (pile 3). The temperature values in the pile 1 showed a different evolution during the thermophilic stage of the composting process in relation to the piles 2 and 3. The thermophilic stage for pile 1 was 17 days, meanwhile for the piles 2 and 3 were around 80 and 110 days, respectively, and probably pile 1 was not well composted. The curves of ion current of CO2 have been recorded in order to shed light on changes occurring in organic matter during composting. Particularly DTG curves allowed us to distinguish between well (piles 2 and 3) and poor (pile 1) stabilized organic matter. The energy released was calculated for each sample by integrating the DTA curves and these results are agreed with the previous hypothesis. Information deriving from weight losses, registered by the TG and DTG curves, enables to follow the evolution state of the organic matter and therefore changes in its stability. These data could determine the final point of the composting process of winery and distillery residues and then reduce the time for compost harvest. 相似文献
16.
This study investigated the biodegradability of PBS and bio-flour, which is a poly(butylene succinate) (PBS) bio-composite filled with rice-husk flour (RHF) reinforcing, in natural and aerobic compost soil. The percentage weight loss and the reduction in mechanical properties of PBS and the bio-composites in the compost soil burial test were significantly greater than those in the natural soil burial test. These results were supported by degraded surface of PBS and bio-composites observed through morphological study and the total colony count of natural soil was lower than that of compost soil. The biodegradability of the bio-composites was enhanced with increasing bio-flour content because the bio-flour is easily attacked by microorganisms. As the biodegradability test progressed over time up to 80 days, the molecular weight of PBS decreased in the soil burial test. We confirmed by attenuated total reflectance (FTIR-ATR) analyser that the chemical structures of PBS and the bio-composites were changed after the compost burial test. The glass transition temperature (Tg), melting temperature (Tm), crystallization temperature (Tc), heat of fusion (ΔHf) and heat of crystallization (ΔHc) of the natural and composted soil tested PBS were investigated using differential scanning calorimetry (DSC). From the results, we concluded that use of these bio-composites will reduce the environmental problems associated with waste pollution and the study findings support the predicted application of bio-composites as “green-composites” or “eco-materials”. 相似文献
17.
J. Rodríguez-Añón J. Proupín-Castiñeiras M. Villanueva-López O. Núñez-Fernández 《Journal of Thermal Analysis and Calorimetry》2007,87(1):15-19
This work is a ‘historical’revision of the evolution of an experimental procedure developed by Prof.Lisardo Núñez and his research group TERBIPROMAT to study thesustainability and the soil health state.From the very beginning,in 1993, the microbial activity was the main bioindicator selected to analysethe ‘soil health state’. For this reason, a microcalorimetrictechnique was used lately to analyse the influence of different human activitiessuch as reforestations, agricultural exploitation or pollution on the microbialactivity in different soils. Microcalorimetry is the main scientific techniqueused in this research to follow the stimulation of the microbial activityby addition of glucose. The data obtained were complemented by a study ofphysical, chemical and biological parameters of soil and allowed to followthe microbial activity in soils of Galicia (Spain) along the year.The final results, still in revision, will be helpful in establishinga data basis for real maps of the ‘health state’ of differentsoils. Such maps could be used to design processes that help us to decidehow we should exploit soils ensuring their sustainability. 相似文献
18.
In order to investigate the occurrence and distribution of organic contaminants in the compost of sewage sludge with rice straw, four different composting treatments at a low carbon/nitrogen (C/N) ratio (13:1) were conducted. Thirty semi-volatile organic compounds (SVOCs) listed as priority pollutants by both China and the US Environmental Protection Agency (EPA) were Soxhlet-extracted, separated and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The results showed that after composting (56 days) most of SVOCs were detected in the final composts. The total concentrations of polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters ranged from 1.8 to 10 mg/kg dry weight (d.w.) and from 9.8 to 18 mg/kg d.w., respectively, being significantly higher than those of chlorobenzenes and nitroaromatic compounds which were generally less than 1.0 mg/kg d.w. The concentrations and predominant compounds of organic contaminants in the different composts varied, and were affected by their physico-chemical properties and the composting processes. Concentrations of SVOCs in the static aerated composting processes especially intermittently aerated composting treatment were considerably lower than those in the manual-turned composting treatments. Concentrations of organic contaminants especially PAHs and di(2-ethylhexyl) phthalate in the final composts were in agreement with the maximum permissible limits for agricultural purposes proposed by the European Union and by the EPA. 相似文献
19.
This study involved comparison of different extraction and derivatization methods for determining FAs in soil and in four
highly organic matrixes (cattle manure, pig slurry, compost, and vermicompost), by application of a multifactor categorical
design. Although some studies have been carried out regarding the application of FA analysis to highly organic matrixes, comparison
and verification are still required to test which methods of extraction and derivatization of FAs function best for these
matrixes. We compared three extraction methods (one in which the same extraction mixture as used in the Folch method was employed,
a modification of the Bligh and Dyer method, and a microwave-assisted extraction) and two derivatization procedures (alkaline
methanolysis and derivatization with trimethylsulfonium hydroxide (TMSH)). The highest yields of FAs belonging to different
structural classes, and of individual FAs used as microbial biomarkers were obtained by application of the same extraction
mixture as in the Folch method and use of TMSH as derivatization agent. These methods also involved a significant reduction
in the complexity and time involved in sample preparation. 相似文献
20.
Junko Konishi Koji Fujita Kazuki Nakanishi Shotaro Nishitsuji Mikihito Takenaka Kiyotaka Miura Kazuyuki Hirao 《Journal of Sol-Gel Science and Technology》2008,46(1):63-69
Titania (TiO2) monoliths with well-defined bicontinuous macropores and gel skeletons were prepared through the alkoxy-derived sol–gel process
accompanied by spinodal decomposition, and the structural evolution during evaporation drying and heat treatment was probed
by a combination of ultra-small-angle X-ray scattering and small-angle X-ray scattering. X-ray scattering profiles of wet
and dried gels revealed that microporous structures related to the existence of primary particles are present in the gel skeletons
at the wet stage and are preserved during drying. Additionally, it is found that the primary particles swollen in the wet
condition are dried to compact aggregates to produce the smooth surface of gel skeletons. Upon heating at 400 °C, the particle–particle
correlation associated with regularity of mesostructures is enhanced. From nitrogen adsorption–desorption measurements, the
average pore size is less than 1 nm in the dried gel and increases to 3.1 nm by the heat treatment. Homogeneous growth of
primary particles due to interparticle-polycondensation reaction is responsible for the increased size and uniform distribution
of mesopores in the heat-treated gel. 相似文献