Biosorption of Malachite Green from Aqueous Solutions onto Polylactide/Spent Brewery Grains Films: Kinetic and Equilibrium Studies

Batch experiments were conducted to study the biosorption of Malachite Green (MG) onto polylactide (PLA)/spent brewery grains (SBGs) films. Films were prepared by solvent-casting method using dichloromethane. Effects of contact time, pH, salt concentration, and optimal experimental condition was evaluated. At pH 6.89 and low salt concentration, Malachite Green was removed effectively. The isotherm data fitted the Freundlich model with 0.969 R² value and 0.738 slope implying chemisorptions process. The biosorption process followed pseudo-second order kinetics with calculated adsorption capacity at equilibrium (qe) of 0.572?mg/g at 23?°C. The investigation showed that PLA/SBGs films are effective in dye removal from textile, paper and leather industries effluents.     

A comparison of the social organization of three syntopic species of Australian thornbill,Acanthiza

Summary Brown (Acanthiza pusilla), buff-rumped (A. reguloides) and striated thronbills (A. lineata) were studied over three years in eucalypt forest in northern New South Wales. All three are small, sexually monomorphic insectivores. A. pusilla is a shrub-feeder, reguloides a bark and ground forager and lineata gleans from eucalypt leaves. A. reguloides and lineata show a two-tiered social organization with territorial clans in the non-breeding season which split up into breeding pairs or groups of 3 or 4. Non-breeding birds feed nestlings and fledglings, and after reformation of the clan adults feed fledglings belonging to other groups. Females tend to disperse more than males before the next breeding season, males tend to stay and help. A. pusilla breeds in pairs, with no helpers, defends year-round territories and expels juveniles a few months after they fledge. We discuss possible reasons why A. pusilla is not cooperative whereas the other two species are. It seems not to be due to greater adult survival and habitat saturation in the latter two, nor to reduced seasonal fluctuations in food. We propose that a major factor is the low risk of dispersing relative to staying at home in pusilla compared with the other two species.     

Environmental factors affecting degradation of perfluorooctanoic acid (PFOA) by In2O3 nanoparticles

Nanophotocatalysts have shown great potential for degrading poly-and perfluorinated substances (PFAS).In light of the fact that most of these catalysts were studied in pure water,this study was designed to elucidate effects from common environmental factors on decomposing and defluorinating perfluorooctanoic acid (PFOA) by In₂O₃ nanoparticles.Results from this work demonstrated that among the seven parameters,pH,sulfate,chloride,H₂O₂,In₂O     

A study of emissions from a Euro 4 light duty diesel vehicle with the European particulate measurement programme

The California Air Resources Board, CARB, has participated in a program to quantify particulate matter (PM) emissions with a European methodology, which is known as the Particulate Measurement Programme (PMP). The essence of the PMP methodology is that the diesel PM from a Euro 4 vehicle equipped with a Diesel Particulate Filter (DPF) consists primarily of solid particles with a size range greater than 23 nm. The PMP testing and the enhanced testing performed by CARB have enabled an increased understanding of both the progress that has been made in PM reduction, and the future remaining challenges for new and improved DPF-equipped diesel vehicles. A comparison of measured regulated emissions and solid particle number emissions with the results obtained by the PMP participating international laboratories was a success, and CARB’s measurements and standard deviations compared well with the other laboratories. Enhanced measurements of the influence of vehicle conditioning prior to testing on PM mass and solid particle number results were performed, and some significant influences were discovered. For example, the influence of vehicle preconditioning on particle number results was significant for both the European and USA test driving cycles. However, the trends for the cycles were opposite with one cycle showing an increase and the other cycle showing a decrease in particle number emissions. If solid particle size distribution and total particle numbers are to be used as proposed in PMP, then a greater understanding of the quality and errors associated with measurement technologies is advisable.In general, particle counting instruments gave results with similar trends, but cycle-to-cycle testing variation was observed. Continuous measurements of particle number concentrations during test cycles have given detailed insight into PM generation. At the present time there is significant variation in the capabilities of the particle counting instruments in terms of particle size and concentration.Current measurements show the existence of a large number of volatile and semi-volatile particles of yet-to-be-resolved chemical composition in diesel exhaust, especially during DPF regeneration, and these particles are not included in the PMP methodology because they are smaller than 20 nm. It will be very challenging to improve our understanding of this class of diesel particulate matter.     

Temporal trends (1990-2000) in the concentration of cadmium, lead and mercury in mosses across Europe

The European heavy metals in mosses survey provides data on the concentration of 10 heavy metals in naturally growing mosses. The survey has been repeated at five-yearly intervals and in this paper we report on the temporal trends in the concentration of cadmium, lead and mercury between 1990 and 2000. Metal- and country-specific temporal trends were observed. In general, the concentration of lead and cadmium in mosses decreased between 1990 and 2000; the decline was higher for lead than cadmium. For mercury not enough data were available to establish temporal trends between 1990 and 1995, but between 1995 and 2000 the mercury concentration in mosses did not change across Europe. The observed temporal trends for the concentrations in mosses were similar to the trends reported for the modelled total deposition of cadmium, lead and mercury in Europe.     

Metals emitted from heavy-duty diesel vehicles equipped with advanced PM and NOX emission controls

Emission factors for elemental metals were determined from several heavy-duty diesel vehicles (HDDV) of 1998–2007 vintage, operating with advanced PM and/or NO_X emissions control retrofits on a heavy-duty chassis dynamometer, under steady state cruise, transient, and idle conditions. The emission control retrofits included diesel particulate filters (DPF): catalyzed and uncatalyzed, passive and active prototype vanadium- or zeolite-based selective catalytic reduction (SCR) systems, and a catalyzed DPF fitted on a hybrid diesel electric drive vehicle. The prototype SCR systems in combination with DPF retrofits are of particular interest because they represent the expected emissions controls for compliance with PM and NO_X regulations in 2010. PM samples from a full-exhaust dilution tunnel were collected on bulk filters, and on a Personal Cascade Impactor Sampler (PCIS) for total and water-soluble elemental analysis. All the DPFs significantly reduced emissions of total trace elements (>85% and >95% for cruise and for the Urban Dynamometer Driving Schedule (UDDS), respectively). However, we observed differences in the post-retrofit metals emissions due to driving cycle effects (i.e., exhaust temperature) and type of retrofit. In general, the metals emissions over cruise conditions (which leads to higher exhaust temperatures) were substantially different from the emissions over a transient cycle or while idling. For instance, during cruise, we observed higher levels of platinum (1.1 ± 0.6–4.2 ± 3.6 ng km^?1) for most of the retrofit-equipped vehicle tests compared to the baseline configuration (0.3 ± 0.1 ng km^?1). The vanadium-based DPF + SCR vehicle during cruise operation exhibited emissions of vanadium (562 ± 265 ng km^?1) and titanium (5841 ± 3050 ng km^?1), suggesting the possible release of actual SCR wash-coat (V₂O₅/TiO₂) from the catalyst under the higher temperatures characteristic of cruise operation. The vanadium emissions exhibited a bi-modal mass size distribution, with modes at <0.25 μm and 1.0–2.5 μm size ranges for the vanadium-based SCR system. For the DPF + SCR systems, a greater fraction of the metal emissions from the zeolite-based system is water-soluble compared to emissions from the vanadium-based system.     

The Validity of Several Plume Rise Formulas

The ground level concentration of pollutants downwind of a tall chimney decreases as the effective height of the stack increases. The effective height of the stack is the actual height plus the rise of the plume center-line due to momentum and buoyancy of the effluent. Over twenty formulas to predict plume rise from stack and meteorological parameters have been proposed; none is uniformly accepted. In this paper, 711 plume rise observations were used to test the ability of fifteen of the published and commonly used formulas to predict plume rise. The plume rise data were obtained from single stacks whose heat emission rate varied over four orders of magnitude. None of the formulas tested was found to be significantly better than the others. Research was performed under the auspices of the U.S. Atomic Energy Commission.     

Male turnover reduces population growth: an enclosure experiment on voles

Turnover of individuals is assumed to cause disruptions of social organization, followed by reduced reproduction and survival. We tested how male turnover (removal of resident males and their replacement by unfamiliar males) affected population performance in experimental root vole (Microtus oeconomus) populations. The treatment simulated predation of adult males, with the subsequent replacement by immigrants, and provided insight into the interaction between extrinsic (i.e., predation) and intrinsic (i.e., social organization) factors. We showed that recruitment and female survival dramatically declined and that reproduction commenced slightly later in treatment populations compared with control populations. The treatment nearly halved the population growth rate. We suspect that recruitment failed due to infanticidal immigrating males. Reduced female survival was particularly apparent in treatment populations in which females exhibited a high degree of spatial overlap. Our experimental results show how males may significantly shape population dynamics and suggest how predation and social factors interact mechanistically.     

Herbicide safeners: uses,limitations, metabolism,and mechanisms of action

Several methods were examined to minimize crops injury caused by herbicides. Thus increase their selectivity. A selective herbicide is one that controls weeds at rates that do not injure the crop. Herbicides are selective in a particular crop within certain limits imposed by the herbicide, the plant, the application rate, the method and time of application, and environment conditions. Herbicide safeners are compounds of diverse chemical families. They are applied with herbicides to protect crops against their injury. Using chemical safeners offer practical, efficient and simple method of improving herbicide selectivity. This method has been applied successfully in cereal crops such as maize, rice and sorghum, against pre-emergence thiocarbamate and chloroacetanilide herbicides. Some reports indicate promising results for the development of safeners for post-emergence herbicides in broadleaved crops. Various hypotheses were proposed explaining mechanisms of action of herbicide safeners: interference with uptake and translocation of the herbicide, alteration in herbicide metabolism, and competition at site of action of the herbicide. Even though progress was made in the development of herbicide safeners and in understanding their mechanisms of action, more research is needed to elucidate clearly how these chemicals act and why their activity is restricted to particular crops and herbicides.     

Age-related shifts in the diet composition of southern elephant seals expand overall foraging niche

Southern elephant seals are important apex predators in a highly variable and unpredictable marine environment. In the presence of resource limitation, foraging behaviours evolve to reduce intra-specific competition increasing a species’ overall probability of successful foraging. We examined the diet of 141 (aged 1–3 years) juvenile southern elephant seals to test the hypotheses that differences between ages, sexes and seasons in diet structure occur. We described prey species composition for common squid and fish species and the mean size of cephalopod prey items for these age groups. Three cephalopod species dominated the stomach samples, Alluroteuthis antarcticus, Histioteuthis eltaninae and Slosarczykovia circumantarcticus. We found age-related differences in both species composition and size of larger prey species that probably relate to ontogenetic changes in diving ability and haul-out behaviour and prey availability. These changes in foraging behaviour and diet are hypothesised to reduce intra-specific food competition concomitant with the increase in foraging niche of growing juveniles.