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1.
Manure-borne estrogens as potential environmental contaminants: a review   总被引:9,自引:0,他引:9  
Livestock wastes are potential sources of endocrine disrupting compounds to the environment. Steroidal estrogen hormones such as estradiol, estrone, and estriol are a particular concern because there is evidence that low nanogram per liter concentrations of estrogens in water can adversely affect the reproductive biology of fish and other aquatic vertebrate species. We performed a literature review to assess the current state of science regarding estrogen physicochemical properties, livestock excretion, and the fate of manure-borne estrogens in the environment. Unconjugated steroidal estrogens have low solubility in water (0.8-13.3 mg L(-1)) and are moderately hydrophobic (log Kow 2.6-4.0). Cattle excrete mostly 17alpha-estradiol, 17beta-estradiol, estrone, and respective sulfated and glucuronidated counterparts, whereas swine and poultry excrete mostly 17beta-estradiol, estrone, estriol, and respective sulfated and glucuronidated counterparts. The environmental fate of estrogens is not clearly known. Laboratory-based studies have found that the biological activity of these compounds is greatly reduced or eliminated within several hours to days due to degradation and sorption. On the other hand, field studies have demonstrated that estrogens are sufficiently mobile and persistent to impact surface and groundwater quality. Future research should use standardized methods for the analysis of manure, soil, and water. More information is needed about the types and amounts of estrogens that exist in livestock wastes and the fate of manure-borne estrogens applied to agricultural lands. Field and laboratory studies should work toward revealing the mechanisms of estrogen degradation, sorption, and transport so that the risk of estrogen contamination of waterways can be minimized.  相似文献   

2.
Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichlorethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L(-1) and reduced simultaneously by Shewanella oneidensis in the presence of H(2), the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenac after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.  相似文献   

3.
This paper discusses the use of the new path modelling approach based on Sequential Orthogonalised PLS regression within the context of consumer science. The method is based on splitting the estimation process into a sequence of modelling steps for each dependent block versus its predictive blocks. Focus will be on how the method can be used to combine individual variables or specific groups of variables in more general blocks with a broader interpretation, such as for instance consumer habits, attitudes and demographic variables. It will be discussed how the methods can solve some of the challenges met when starting a path modelling process. It will be explored how the method handles multidimensionality of the blocks and thus how the analysis is simplified, at least for explorative purposes, as compared to other more traditional path modelling approaches. The study shows that important relations are revealed in presence of different types of information like product attributes, consumer characteristics and acceptance.  相似文献   

4.
Abstract

Food contaminants are challenging the food industry due to the inefficiency of conventional decontamination techniques. Cold plasma as an emerging technique for the degradation of food contaminants attracted notable attention. The current study overviews the plasma-induced degradation of food contaminants, discusses the mechanisms involved, points its benefits and drawbacks out, highlights the research needed in this area, and explores future trends. According to the literature, cold plasma efficiently degraded many common pesticides (e.g. parathion, paraoxon, omethoate, dichlorvos, malathion, azoxystrobin, cyprodinil, fludioxonil, cypermethrin, and chlorpyrifos) and food allergens (e.g. tropomyosin, b-conglycinin, glycinin, trypsin inhibitor, and Kunitztype trypsin inhibitor). These degradations occurred primarily due to the presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the plasma that attack the chemical bonds of food contaminants. The type of pesticide degrades are highly dependent on the concentrations of plasma-generated ROS and RNS. Research showed that several parameters, such as plasma generation device, plasma exposure time, plasma power, and the carrier gas composition, influence the type and concentration of reactive species (e.g. ROS and RNS) and the overall efficiency of cold plasma degradation for a specific pesticide or allergen.
  • Highlights
  • Cold plasma can be used for degradation of many types of pesticides and allergens.

  • Plasma-generated reactive species and UV can interact with pesticides and allergens.

  • The scaled up removal of pesticides and allergens by plasma can be challenging.

  相似文献   

5.
6.
《Food chemistry》2001,74(3):289-291
Contents of Zn, Cd and Pb in honey samples (15) from the Pomeranian region were determined by atomic absorption spectrometer AAS. The mean values for Zn, Cd and Pb were 7.76, 0.015 and 0.048 mg/kg, respectively. Also determined in the honey samples were invert sugar, sucrose, HMF, diastase activity, pH, electrical conductivity, moisture and mechanical pollutions. Pomeranian honeys were of good quality, but they were not free of heavy metals. Results suggested that honey may be useful for assessing the presence of environmental contaminants.  相似文献   

7.
Br concentration in bread for baked bread products was shown to be linearly proportional to the amount of Br added per kg of flour used to make the product. Br concentration in bread can be used to help identify those bread products with the greatest likelihood of containing bromate residues. Instrumental neutron activation analysis was used to determine Br in test portions of bread products from commercial bakeries, homemade bread, flour, and unbaked dough. High performance liquid chromatography was used to determine the bromate residue in selected test portions.  相似文献   

8.
The goal of this preliminary study was to produce an alternative tool for measuring the amount of sucrose in samples without pre‐treatment and use it in the sugarcane field or mobile units. The technology developed makes payment for the sugarcane much more reliable to the producer and also can improve the quality control of the final product. A flow injection analysis system for measuring sucrose using invertase (E.C. 3.2.1.26), and glucose oxidase (E.C.1.1.3.4) (GOD) was developed. The biosensor was made using invertase and GOD incorporated into active graphite paste mixed with tetracyanoquinodimethane as mediator. The system was able to measure sucrose from 50 up to 200 mmol L?1 with a response time of 5 min using 400 µL of sample in 100 mmol L?1 phosphate buffer pH 6.5. This sucrose biosensor showed a sensitivity of 174 ± 8.7 nA mg?1 of sucrose, being a robust system to measure high concentrations of sucrose in sugarcane crops and industrial and fermentation processes, without dilution or pre‐treatment of the samples. Interference from organic acids, mainly ascorbic acid (+350 mV versus Ag/AgCl), was reduced in this system using the potential of 100 mV vs. Ag/AgCl. The active electrode was stable during 2 months at 4 °C. Copyright © 2007 Society of Chemical Industry  相似文献   

9.
10.
Recycling of plastics for food-contact packaging is an important issue and research into meaningful and cost-effective solutions is in progress. In this paper, the use of sub-critical water was evaluated as an alternative way of purifying poly(ethylene terephthalate) (PET) flakes for direct food contact applications. The effects of temperature, pressure and flow rate were assessed on the extraction efficiency of two of the most challenging classes of contaminants (toluene and benzophenone) from PET by sub-critical water using a first-order fractional experimental design. Extraction yield was quantified using GC/FID. The most important parameter was flow rate, indicating that the decrease in sub-critical water polarity with temperature was insufficient to eliminate partition effects. Temperature was also important, but only for the optimization of toluene extraction. These results may be explained by the poor solubility of higher molar mass compounds in sub-critical water compared to lower molar mass compounds under the same conditions, and the small decrease in dielectric constant with temperature under the experimental conditions evaluated. As cleaning efficiency is low and PET is very susceptible to hydrolysis, which limits the use of higher temperatures vis-à-vis physical recycling, the proposed extraction is unsuitable for a standalone super-clean process but may be a step in the process.  相似文献   

11.
The first worldwide interlaboratory study on the analyses of 13 perfluorinated compounds (PFCs) in three environmental and two human samples indicates a varying degree of accuracy in relation to the matrix or analyte determined. The ability of 38 participating laboratories from 13 countries to determine the analytes in the various matrices was evaluated by calculation of z-scores according to the Cofino model. The PFCs which were reported most frequently by the laboratories, and assessed with the most satisfactory agreement, were perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In general, the level of agreement between the participating laboratories decreased in the following order: PFC standard solution (76% satisfactory z-scores of <[2]1 for PFOS) < human blood (67%) < human plasma (63%) < fish liver extract (55%) < water (31%) < fish tissue (17%). This shows that relative good agreement between laboratories was obtained for the study of standard and human matrices. For the fish extract, most laboratories underestimated the actual PFOS concentration due to matrix effects. The results for the fish tissue and water are also poor, indicating that the extraction and cleanup steps require further improvement. It was concluded that the PFC determinations in various matrices are not yet fully mastered.  相似文献   

12.
Titanium oxide nanotubes were successfully grown from a titanium plate by direct anodic oxidation with 0.2 wt % hydrofluoric acid being the supporting electrolyte. These nanotubes are of uniform size and are well-aligned into high-density arrays. They look like honeywell with the structure similar to that of porous alumina obtained by the same technique. TiO2 anatase phase was identified by X-ray diffraction. Significant blue-shift in the spectrum of UV- vis absorption was observed. The mechanism of the novel, simple, and direct growth of the nanotubes was postulated. To investigate their potentials in environmental applications, degradation of pentachlorophenol (PCP) in aqueous solution was carried out using photoelectrocatalytic (PEC) processes, comparing with electrochemical process (EP) and photocatalytic (PC). A significant photoelectrochemical synergetic effect was observed. The kinetic constant of PEC degradation of PCP using TiO2 nanotubes electrode was 86.5% higher than that using TiO2 film electrode. In degrading PCP, 70% of TOC was removed using the TiO2 nanotubes electrode against 50% removed using TiO2 film electrode formed by sol-gel method in 4 h under similar conditions.  相似文献   

13.
A representative leather tannery industry in a Latin American developing country has been studied from an environmental point of view, including both technical and economic analysis. Life Cycle Analysis (LCA) methodology has been used for the quantification and evaluation of the impacts of the chromium tanning process as a basis to propose further improvement actions. Four main subsystems were considered: beamhouse, tanyard, retanning, and wood furnace. Damages to human health, ecosystem quality, and resources are mainly produced by the tanyard subsystem. The control and reduction of chromium and ammonia emissions are the critical points to be considered to improve the environmental performance of the process. Technologies available for improved management of chromium tanning were profoundly studied, and improvement actions related to optimized operational conditions and a high exhaustion chrome-tanning process were selected. These actions related to the implementation of internal procedures affected the economy of the process with savings ranging from US dollars 8.63 to US dollars 22.5 for the processing of 1 ton of wet salt hides, meanwhile the global environmental impact was reduced to 44-50%. Moreover, the treatment of wastewaters was considered in two scenarios. Primary treatment presented the largest reduction of the environmental impact of the tanning process, while no significant improvement for the evaluated impact categories was achieved when combining primary and secondary treatments.  相似文献   

14.
Data from 3,200 Holstein cows from 3 commercial dairy farms in Germany were used to estimate heritabilities and breeding values for liability to udder diseases (UD), fertility diseases (FD), metabolic diseases (MD), and claw and leg diseases (CLD) using single-trait threshold sire models. A total of 92,722 medical treatments recorded from 1998 to 2003 were included in the analysis. Approximate genetic correlations between persistency of milk yield, fat yield, protein yield, and persistency of milk energy yield and liability to the health traits were calculated based on correlations between EBV. Posterior means of heritability of liability ranged from 0.05 to 0.08 for UD, from 0.04 to 0.07 for FD, from 0.08 to 0.12 for MD, and from 0.04 to 0.07 for CLD. Approximate genetic correlations of the disease traits with the persistency traits were favorable, except for MD in all lactations, which were unfavorable, and UD, which were around zero. Highest correlations in the range of 0.13 to 0.46 were found between the different persistency traits and CLD.  相似文献   

15.
16.
Over the last decades, the exploration of new natural sources for obtaining valuable compounds, which can be used in food technology, has been a research challenge. Several natural products, such as fruits, juices, natural extracts, have been proposed. Today, many different technologies are being tested to carry out the extraction of different high-added value compounds (nutraceuticals, phenolic compounds, antioxidants, anthocyanins, saccharides), in which the membrane-based technologies (microfiltration, ultrafiltration, and nanofiltration) have been considered thanks to their intrinsic properties. In fact, these pressure-driven membrane processes are addressed as a promising alternative based on their ability to recover, separate, and fractionate different high-added-value compounds from different aqueous systems. To date, ultrafiltration and nanofiltration have shown the capability to meet the current valorization protocols.The aim of this paper is to provide a critical review of the main natural products processed by membrane technologies for the recovery of high-added value compounds. State-of-the-art of developments in the field are described. Particular attention is paid to experimental results reported for the separation of bioactive compounds and their derivatives of different molecular weight. The literature data are analyzed and discussed in relation to separation technologies, molecule properties, membrane characteristics and other interesting phenomena that occur during their recovery.  相似文献   

17.
Ribotyping was used for characterisation of 68 Clostridium botulinum strains and five related Clostridium species to determine the applicability of this method for identification of species causing human botulism. Thirteen restriction enzymes were initially tested for suitability for ribotyping of C. botulinum, of which EcoRI and HindIII were selected. Both enzymes clearly differentiated between proteolytic (group I) and a nonproteolytic (group II) strains of C. botulinum, and can be recommended for Group/species identification. Using a commercial software package (GelCompar), a numerical analysis of the discriminatory abilities of EcoRI and HindIII ribotyping within and between the two C. botulinum groups was performed. EcoRI had the higher discriminatory index (0.982), but the ribopatterns generated with group II strains were partly muddled and difficult to interpret. All HindIII ribopatterns were easy to analyse and the discriminatory index for all strains was almost equally high (0.954), whereas this enzyme did not discriminate well between group I isolates. The Clostridium strains diverged at 35+/-13% (mean+/-standard deviation) Dice similarity in dendrograms based on cluster analysis of the ribotyping results. These findings are in good agreement with taxonomical ribotyping studies with other bacterial genera, indicating that ribotyping is a highly suitable method for C. botulinum species identification.  相似文献   

18.
提到纺织杂质,本能的反应就会说第一步就是防止杂质落入已采摘的棉花中。当然在这方面作了很多努力,包括采摘棉花时用棉质包袋取代通常使用的黄麻或者聚丙烯袋,或者对棉花质量进行检查。在棉花打包的过程中也采取了预防措施,并且每个人都有相关的预防杂质的方法。  相似文献   

19.
An audit toolkit was developed to enable food companies to measure their suppliers in terms of environmental management. Environmental practices and performance metrics were audited using a customised survey that enabled the quantification of best practice, common practice and areas for improvement. It was tested on six suppliers to a major fresh food company. Key areas of best practice included separation and recycling of waste streams, efforts to reduce use of raw materials, energy, water, pesticides, herbicides and fertilisers. Some suppliers were working with stakeholders to reduce environmental impacts. The supplier with the best environmental performance had developed and implemented an Environmental Management Policy and was working towards ISO 14001 accreditation. The study identified four areas for improvement by the suppliers. These were the implementation of an Environmental Management System, the sourcing of more renewable materials and energy, the systematic measurement of the food miles of products and carbon and water footprinting.  相似文献   

20.
Cows with high lactation persistency tend to produce less milk than expected at the beginning of lactation and more than expected at the end. Best prediction of lactation persistency is calculated as a function of trait-specific standard lactation curves and linear regressions of test-day deviations on days in milk. Because regression coefficients are deviations from a tipping point selected to make yield and lactation persistency phenotypically uncorrelated it should be possible to use 305-d actual yield and lactation persistency to predict yield for lactations with later endpoints. The objectives of this study were to calculate (co)variance components and breeding values for best predictions of lactation persistency of milk (PM), fat (PF), protein (PP), and somatic cell score (PSCS) in breeds other than Holstein, and to demonstrate the calculation of prediction equations for 400-d actual milk yield. Data included lactations from Ayrshire, Brown Swiss, Guernsey (GU), Jersey (JE), and Milking Shorthorn (MS) cows calving since 1997. The number of sires evaluated ranged from 86 (MS) to 3,192 (JE), and mean sire estimated breeding value for PM ranged from 0.001 (Ayrshire) to 0.10 (Brown Swiss); mean estimated breeding value for PSCS ranged from −0.01 (MS) to −0.043 (JE). Heritabilities were generally highest for PM (0.09 to 0.15) and lowest for PSCS (0.03 to 0.06), with PF and PP having intermediate values (0.07 to 0.13). Repeatabilities varied considerably between breeds, ranging from 0.08 (PSCS in GU, JE, and MS) to 0.28 (PM in GU). Genetic correlations of PM, PF, and PP with PSCS were moderate and favorable (negative), indicating that increasing lactation persistency of yield traits is associated with decreases in lactation persistency of SCS, as expected. Genetic correlations among yield and lactation persistency were low to moderate and ranged from −0.55 (PP in GU) to 0.40 (PP in MS). Prediction equations for 400-d milk yield were calculated for each breed by regression of both 305-d yield and 305-d yield and lactation persistency on 400-d yield. Goodness-of-fit was very good for both models, but the addition of lactation persistency to the model significantly improved fit in all cases. Routine genetic evaluations for lactation persistency, as well as the development of prediction equations for several lactation end-points, may provide producers with tools to better manage their herds.  相似文献   

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