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101.
Volatile organic compounds produced during the aerobic biological processing of municipal solid waste in a pilot plant 总被引:5,自引:0,他引:5
Pierucci P Porazzi E Martinez MP Adani F Carati C Rubino FM Colombi A Calcaterra E Benfenati E 《Chemosphere》2005,59(3):423-430
The volatile organic carbon (VOC) and odours emitted during the aerobic biological processing of municipal solid waste (MSW) was studied in a pilot-scale reactor. VOCs were detected by different techniques on solid waste samples and the outlet air stream, before and after a biofilter. Organic compounds (alpha-pinene, beta-myrcene, D-limonene) were also measured in condensate water and leachate from the process. Results showed uniformity in the composition of the air in the solid waste samples, air sampled during the process and condensed water, indicating a matrix-derived origin of these compounds. Leachates, however, contained substances with a quite different molecular structure from the compounds identified in the gaseous fraction. Most of the substances in the gaseous effluent had a hydrocarbon-like structure, mainly terpenoids. The odour produced and detected through olfactometry agreed with GC-MS analyses. This was true above all for terpenes. 相似文献
102.
A method based on SPME is described for assessing the gaseous dichlorvos concentration in confined atmospheres like a greenhouse after a pesticide application. Sampling was made by using SPME with PDMS fibres immersed into a 250 mL sampling flask into which air samples were dynamically pumped from the analysed atmosphere. Sampling duration was 40 min and samples were then analysed by GC-MS. Calibration was performed from a vapour saturated air sample and gas phase diluted samples, and this procedure afforded a curve with a regression coefficient (R2) higher than 0.98. The repeatability of these measurements was observed with an RSD of 2.5%. This analysis procedure was then applied for the determination of gaseous dichlorvos concentrations versus time, in the atmosphere of an experimental 8 m2 and 20 m3 greenhouse. The pesticide was sprayed according to real cultivation conditions and measurements were made from 2 up to 74 h after application affording observed concentrations in the range of decades and hundreds of microg m(-3) (corresponding limits of detection and quantification were found at the level of a few microg m(-3)). 相似文献
103.
Maggi Kraft David E. Rosenberg Sarah E. Null 《Journal of the American Water Resources Association》2019,55(2):382-400
Instream barriers, such as dams, culverts, and diversions, alter hydrologic processes and aquatic habitat. Removing uneconomical and aging instream barriers is increasingly used for river restoration. Historically, selection of barrier removal projects used score‐and‐rank techniques, ignoring cumulative change and the spatial structure of stream networks. Likewise, most water supply models prioritize either human water uses or aquatic habitat, failing to incorporate both human and environmental water use benefits. Here, a dual‐objective optimization model identifies barriers to remove that maximize connected aquatic habitat and minimize water scarcity. Aquatic habitat is measured using monthly average streamflow, temperature, channel gradient, and geomorphic condition as indicators of aquatic habitat suitability. Water scarcity costs are minimized using economic penalty functions while a budget constraint specifies the money available to remove barriers. We demonstrate the approach using a case study in Utah's Weber Basin to prioritize removal of instream barriers for Bonneville cutthroat trout, while maintaining human water uses. Removing 54 instream barriers reconnects about 160 km of quality‐weighted habitat and costs approximately US$10 M. After this point, the cost‐effectiveness of removing barriers to connect river habitat decreases. The modeling approach expands barrier removal optimization methods by explicitly including both economic and environmental water uses. 相似文献
104.
Donald R. Glenn John G. Federico 《Journal of the American Water Resources Association》1971,7(5):1081-1092
ABSTRACT. Over the last few years, several studies sponsored by both government and interested national engineering associations have evaluated the relative merits of pressure sewer systems. Surprisingly little data has been forthcoming, however, with regard to the effects of pressure sewers on both the economics of land development and the country's water resources. The intention of our paper is to detail the salutary effects of pressure sewers on water supply resources, the indirect effect on other resources by decreasing the contribution of sanitary sewage to their pollution, and to illustrate where, in some locations of the country, pressure sewers would benefit the economics of land development. As engineers from a large industrial firm that has built hardware that will allow the concepts stated above to become realities, we will present data to enforce our convictions. Some effects on municipal treatment plants, and emplacement costs of the system are described. Since the main thrust of our paper is to treat the effect of pressure sanitary sewers on the water resources of the country, specific peripheral data is not presented at length. The pressure sewer effects on lowering water usage in homes and the decrease in groundwater contamination by replacing septic tanks with pressure sewers in selected locations is presented. Advanced technology concepts such as energy assisted sewer systems should be considered as a favorable economic manner in which to preserve selected water resources. During the 1965 drought that affected the Northeastern section of the U.S., a federal government document reported that there was really no shortage of water, but that present water resources lacked management. Pressure sewers may be a water resources management tool and an effective one if not promulgated as a cure-all for the water pollution problems facing this nation. 相似文献
105.
Gabriel G. González Katherina B. Brokordt Federico E. Winkler 《Marine Biology》2010,157(10):2195-2203
Several studies on individual physiological traits assume that past records may predict future performance. Marine mollusks,
as other animals, show a wide range of between- and within-individual variation of physiological traits. However, in this
group, almost nothing is known about the relative influence of genetic factors on that variation. Repeatability (R) is a measure of the consistency of the variation of a trait, which includes its genetic variance and represents the maximum
potential value of its heritability (h
2). Traits that show high inter-individual variation and high repeatability levels could potentially evolve through selection
(natural or artificial). We estimated the repeatability [using intra-class (τ) and Pearson-moment (r) correlation coefficients] of several physiological traits related to energy acquisition and allocation in juvenile Pacific
abalone Haliotis discus hannai, maintained under controlled environment growing systems. In order to estimate the range of the R values and the effect of the time elapsed between measurements on these estimates, we measured these traits monthly during
6 months for each individual. Among the physiological traits, those related to energy allocation like oxygen consumption (standard
metabolic rate, SMR) and ammonium excretion rates, and oxygen/nitrogen ratio (O/N), showed intermediate levels of repeatability
(0.48, 0.55 and 0.39, respectively), when this was estimated by τ coefficient. However, the r estimation showed that SMR and O/N repeatability were significant and high (0.6–0.7 and 0.5–0.7, respectively) during the
first 5 consecutive measurements, decreasing strongly (0.3 and 0.2, respectively) during the last measurement. For ammonia
excretion, although repeatability (r) decreased from 0.8 to 0.5 during the 6 consecutive measurements, they remain significant during the experimental period.
Therefore, our results indicate that for H. discus hannai juveniles, physiological traits like SMR, ammonia excretion and O/N are significantly repeatable (i.e. good predictors of
future measurements) during a period of 4–5 months. These significant repeatability values suggest an important genetic control
upon the phenotypic variation of these physiological traits, and could potentially respond to natural or artificial selection,
and be used in genetic improvement programs. By contrast, those traits related to energy acquisition (i.e. ingestion, absorption
and assimilation) and physiological efficiencies (i.e. net growth and scope for growth) showed very low levels of repeatability
(0–0.07). This indicates that the phenotypic variation of these traits would be more influenced by environment rather than
by genetic factors. 相似文献
106.
Silvana Povolo Maria Giovanna Romanelli Federico Fontana Marina Basaglia Sergio Casella 《Journal of Polymers and the Environment》2012,20(4):944-949
The production of polyesters from triglyceride containing substrates was investigated. A first filter step based on lipase activity was followed and those bacteria potentially able to degrade oils or animal fats were further tested for their polymer accumulation properties, selected and kept for further studies. In a second step, bacteria were directly grown on animal fats and/or vegetable oils, and polyhydroxyalkanoates (PHAs) accumulation was verified under appropriate incubation conditions. Each substrate, whether of animal or vegetable derivation, supported the growth of a number of the newly isolated strains and among those, some strains were also found to produce reasonably high amounts of PHA. The repeat-unit composition of the polyesters was determined by gas chromatography (GC) analysis of the ?-hydroxyalkanoate methyl esters from the hydrolyzed polymer and some class of co-polymers were also detected. These properties, coupled with the ability of some of the selected isolates to grow and produce lipases on a minimal medium, could be considered as promising in view of possible industrial applications. The overall results indicate that PHAs could be produced from waste containing considerable amounts of fat, oil and grease (FOG), that generally need to be treated for their disposal. 相似文献
107.
Federico?AndreisEmail authorView authors OrcID profile Marco?Bonetti 《Environmental and Ecological Statistics》2018,25(1):139-154
We introduce a novel method to extract a sample from a finite population where units with desired characteristics are over-represented. The approach is both sequential and adaptive and allows, via suitable compositions of predictive and objective functions, to target specific subsets of the population. We consider the problem of estimation and conjecture the validity of a modified Horvitz–Thompson estimator capable to account for the imbalance induced by the targeting procedure. After discussing how to apply the method to the sampling of geographically distributed units, we investigate its potential via simulations. 相似文献
108.
Paula Federico Thomas G Hallam Gary F McCracken S Thomas Purucker William E Grant A Nelly Correa-Sandoval John K Westbrook Rodrigo A Medellin Cutler J Cleveland Chris G Sansone Juan D López Margrit Betke Arnulfo Moreno-Valdez Thomas H Kunz 《Ecological applications》2008,18(4):826-837
During the past 12000 years agricultural systems have transitioned from natural habitats to conventional agricultural regions and recently to large areas of genetically engineered (GE) croplands. This GE revolution occurred for cotton in a span of slightly more than a decade during which a switch occurred in major cotton production areas from growing 100% conventional cotton to an environment in which 95% transgenics are grown. Ecological interactions between GE targeted insects and other insectivorous insects have been investigated. However, the relationships between ecological functions (such as herbivory and ecosystem transport) and agronomic benefits of avian or mammalian insectivores in the transgenic environment generally remain unclear, although the importance of some agricultural pest management services provided by insectivorous species such as the Brazilian free-tailed bat, Tadarida brasiliensis, have been recognized. We developed a dynamic model to predict regional-scale ecological functions in agricultural food webs by using the indicators of insect pest herbivory measured by cotton boll damage and insect emigration from cotton. In the south-central Texas Winter Garden agricultural region we find that the process of insectivory by bats has a considerable impact on both the ecology and valuation of harvest in Bacillus thuringiensis (Bt) transgenic and nontransgenic cotton crops. Predation on agricultural pests by insectivorous bats may enhance the economic value of agricultural systems by reducing the frequency of required spraying and delaying the ultimate need for new pesticides. In the Winter Garden region, the presence of large numbers of insectivorous bats yields a regional summer dispersion of adult pest insects from Bt cotton that is considerably reduced from the moth emigration when bats are absent in either transgenic or non-transgenic crops. This regional decrease of pest numbers impacts insect herbivory on a transcontinental scale. With a few exceptions, we find that the agronomics of both Bt and conventional cotton production is more profitable when large numbers of insectivorous bats are present. 相似文献
109.
Antonio Proto Raffaele Cucciniello Federico Rossi Oriana Motta 《Environmental science and pollution research international》2014,21(4):3182-3186
In this paper, stable carbon isotope ratios (δ 13C) were determined in the atmosphere by using a Ca-based sorbent, CaO/Ca12Al14O33 75:25 w/w, for passively collecting atmospheric CO2, in both field and laboratory experiments. Field measurements were conducted in three environments characterized by different carbon dioxide sources. In particular, the environments under consideration were a rather heavily trafficked road, where the source of CO2 is mostly vehicle exhaust, a rural unpolluted area, and a private kitchen where the major source of CO2 was gas combustion. Samplers were exposed to the free atmosphere for 3 days in order to allow collection of sufficient CO2 for δ13C analysis, then the collected CO2 was desorbed from the adsorbent with acid treatment, and directly analyzed by nondispersive infrared (NDIR) instrument. δ 13C results confirmed that the samplers collected representative CO2 samples and no fractionation occurred during passive trapping, as also confirmed by an appositely designed experiment conducted in the laboratory. Passive sampling using CaO/Ca12Al14O33 75:25 w/w proved to be an easy and reliable method to collect atmospheric carbon dioxide for δ 13C analysis in both indoor and outdoor places. 相似文献
110.
Marcello Corazza Federico Maria Tardella Carlo Ferrari Andrea Catorci 《Environmental management》2016,57(6):1247-1261