Heterogeneous photocatalysis is highlighted to treat volatile organic compound (VOC) emission. Then, this work analysed the influence of palladium (Pd) content loaded in TiO2 on n-octane and iso-octane photodegradation. For this, TiO2 was loaded with Pd in different contents: 0.4%, 0.7%, and 1.0%. The samples were characterized, and the photodegradation experiments were conducted by Pd/TiO2/UV process. The characterization analyses showed that the metal presence did not change the catalyst structure or its surface area; however, it reduced the bandgap energy. The photocatalytic results proved that palladium improved n-octane degradation from 62% (pure TiO2) to 92.6% (0.4%Pd/TiO2) and, iso-octane degradation enhanced from 59% (pure TiO2) to 90.6% (0.7%Pd/TiO2); all results were obtained in the space time of 39 s. Therefore, 0.4%Pd/TiO2 and 0.7%Pd/TiO2 showed better oxidation results to degradation n-octane and iso-octane, respectively. The kinetic model of pseudo-first order showed a good fit for the data of both VOCs. Heterogeneous photocatalysis with Pd/TiO2 showed to be an adequate technique to reduce VOCs emission.
Environmental Science and Pollution Research - Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous... 相似文献
Environmental Modeling & Assessment - Extreme or recurrent drought events are the principal source of stress on forests, impairing their overall health. They result in financial losses for... 相似文献
Size advantage in male–male competition over mates, combined with male preference over large females, is a common feature
that can drive to size assortative mating and, eventually, sexual selection. In crabs, appendage autotomy can affect assortative
mating and opportunity for sexual selection by affecting size advantage in mating contests. In this work, we evaluate the
effect of size and appendage autotomy in generating assortative mating in the mud crab Cyrtograpsus angulatus. Field observations of guarding pairs in two different populations show a positive correlation between carapace width of
males and females in both the populations. In one of the populations, incidence of appendage autotomy was low and the variability
in the size of reproductive males was lower than the variability in the size of randomly collected males (i.e. only larger
males were successful in getting a female), whereas there was no differences in the other population (i.e. most male sizes
were successful) where the incidence of appendage autotomy was very high, indicating that the importance of size is higher
when the incidence of autotomy is low. In this context, experiments (in both populations) show that, in contests for a female,
larger males outcompete smaller ones only when they had intact appendages. When males had missing chelipeds, winning or loosing
against smaller males was random. This may lead to a decrease in the importance of male size in populations with high incidence
of cheliped autotomy, affecting assortative mating and opportunity for selection and, thus, affecting selective pressures. 相似文献
In the presence of local (sulfur) and global (carbon) pollutants, we examine the pollution haven hypothesis and free riding behavior. Under domestic emissions trading, poorer Southern countries become pollution havens when free trade opens up whenever sulfur damage functions are linear or when sulfur levels in equilibrium are not higher in the South. With global trading of carbon permits, the pollution haven effect emerges in equilibrium whenever the convex sulfur damage functions are nonlinear. Countries that do not participate in a Global Protocol designed to reduce carbon emissions enjoy double benefits, stemming from free riding and cleaner local environments. 相似文献
The SALLJEX experiment was held during the summer 2002–2003. It consisted of three-dimensional observation of the atmosphere
to study the structure of the low level jet along the eastern slopes of the Andes. Daily precipitation water samples were
collected at two stations (Resistencia and Salta) in northern Argentina and isotope content was analyzed. The isotope data
were used in conjunction with air parcel trajectories obtained from a 3-D kinematic model (3D-MTC) developed by the University
of Sao Paulo, Brazil. Values of deuterium excess were related with air masses of continental origin, whilst low values were
associated with air masses with longer oceanic trajectories. Furthermore, although data are scarce, results show that oxygen-18
and deuterium excess in rainwater are related with the occurrence of the low level jet. 相似文献
The current paper presents the concentration, distribution, and modes of occurrence of trace elements of 13 coals from south
Brazil. The samples were collected in the state of Santa Catarina. Chemical analyses and the high ash yields indicate that
all studied coals are rich in mineral matter, with SiO2 and Al2O3 dominating as determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Quartz is the main mineral
species and is associated with minor levels of feldspars, kaolinite, hematite, and iron-rich carbonates. The contents of trace
elements, including As, Pb, Cd, Ni, Cr, Mn, Be, V, U, Zn, Li, Cu, Tl, and Ni, in coals were determined. A comparison of ranges
and means of elemental concentrations in Santa Catarina, Brazil, and world coals shows that the ranges of most elements in
Santa Catarina coal are very close to the usual worldwide concentration ranges in coal. 相似文献
This paper describes a direct analysis study carried out in a recycling unit for waste electrical and electronic equipment (WEEE) in Portugal to characterize the plastic constituents of WEEE. Approximately 3400 items, including cooling appliances, small WEEE, printers, copying equipment, central processing units, cathode ray tube (CRT) monitors and CRT televisions were characterized, with the analysis finding around 6000 kg of plastics with several polymer types. The most common polymers are polystyrene, acrylonitrile-butadiene-styrene, polycarbonate blends, high-impact polystyrene and polypropylene. Additives to darken color are common contaminants in these plastics when used in CRT televisions and small WEEE. These additives can make plastic identification difficult, along with missing polymer identification and flame retardant identification marks. These drawbacks contribute to the inefficiency of manual dismantling of WEEE, which is the typical recycling process in Portugal. The information found here can be used to set a baseline for the plastics recycling industry and provide information for ecodesign in electrical and electronic equipment production. 相似文献
Citrus Sudden Death (CSD) is a disease that has affected sweet orange trees grafted on Rangpur lime in the south of Minas Gerais state and in the north of São Paulo state (Brazil). This is a worrying characteristic because the Rangpur lime responds to 85% of the Brazilian citrus rootstocks. This disease is believed to be caused by a virus transmitted by aphids (vector) of the citrus. In this work, we have adopted the Cellular Automata model (CA) to study the temporal evolution of the disease. We take into account the effect of the wind in the space covered by the aphid. To establish the relationship between the space covered by the aphid and the intensity of the wind, we have adopted the rule-based fuzzy system. Simulations were performed and compared to real data. Through the use of the mean absolute error (MAE) method, it was possible to verify a 70% of similarity between our model of data and the real one. 相似文献