The evolution of December 2004 tsunami deposits: Temporal and spatial distribution of potentially toxic metalloids

The article presents the results of research into the content of metalloid fractions in the tsunami deposits from southern Thailand. The following fractions, which are potentially most easily released from deposits to the environment, have been distinguished: the water soluble fraction, the exchangeable fraction extracted with the phosphate buffer and the fraction eluted with the solution of hydrochloric acid. The analytical technique atomic absorption spectrometry with hydride generation was applied. Spatial variability of the metalloid fractions in deposits and changes occurring in deposits over a period of several years of observation were determined. Based on the statistical analysis of the results, an attempt was made to determine the post-depositional release of deposits components to the environment. Based on the conducted research, the 4 years forming process of the arsenic, antimony and selenium occurrence after the deposition of sediments on land were described, as well as the balance in the amount of deposit components released to the environment.     

Rapid analysis of neonicotinoid insecticides in guttation drops of corn seedlings obtained from coated seeds

Regarding the hypothesis that neonicotinoid insecticides used for seed coating of agricultural crops - mainly corn, sunflower and seed rape - are related to the extensive death of honey bees, the phenomenon of corn seedling guttation has been recently considered as a possible route of exposure of bees to these systemic insecticides. In the present study, guttation drops of corn plants obtained from commercial seeds coated with thiamethoxam, clothianidin, imidacloprid and fipronil have been analyzed by an optimized fast UHPLC-DAD procedure showing excellent detection limits and accuracy, both adequate for the purpose. The young plants grown both in pots - in greenhouse - and in open field from coated seeds, produced guttation solutions containing high levels of the neonicotinoid insecticides (up to 346 mg L(-1) for imidacloprid, 102 mg L(-1) for clothianidin and 146 mg L(-1) for thiamethoxam). These concentration levels may represent lethal doses for bees that use guttation drops as a source of water. The neonicotinoid concentrations in guttation drops progressively decrease during the first 10-15 days after the emergence of the plant from the soil. Otherwise fipronil, which is a non-systemic phenylpyrazole insecticide, was never detected into guttation drops. Current results confirm that the physiological fluids of the corn plant can effectively transfer neonicotinoid insecticides from the seed onto the surface of the leaves, where guttation drops may expose bees and other insects to elevated doses of neurotoxic insecticides.     

Analysis of energy recovery potential using innovative technologies of waste gasification

In this paper, two alternative thermo-chemical processes for waste treatment were analysed: high temperature gasification and gasification associated to plasma process. The two processes were analysed from the thermodynamic point of view, trying to reconstruct two simplified models, using appropriate simulation tools and some support data from existing/planned plants, able to predict the energy recovery performances by process application. In order to carry out a comparative analysis, the same waste stream input was considered as input to the two models and the generated results were compared. The performances were compared with those that can be obtained from conventional combustion with energy recovery process by means of steam turbine cycle. Results are reported in terms of energy recovery performance indicators as overall energy efficiency, specific energy production per unit of mass of entering waste, primary energy source savings, specific carbon dioxide production.     

Combustion sources of particles. 1. Health relevance and source signatures

Combustion processes result in generation of a large number of particle and gaseous products that create health and environmental risks. Of particular importance are the very small particles that are emitted in large quantities from all the combustion sources, and that have been shown to be potentially more significant in terms of their impact on health than larger particles. To control and mitigate the particles with a view of health and environmental risk reduction, a good understanding is necessary of the relative and absolute contribution from the emission sources to the airborne concentrations. This understanding could only be achieved by developing source signature libraries through direct emission measurements from the sources on one hand, and by measuring particle concentrations in the air, and apportioning them to the specific local and distant sources using the signatures, on the other hand. This paper is a review of particle characteristics that are used as source signatures as well as their general advantages and limitations. The second part of the paper reviews source signatures of the most common combustion pollution sources.     

Combustion sources of particles: 2. Emission factors and measurement methods

Emissions from the combustion of biomass and fossil fuels are a significant source of particulate matter (PM) in ambient outdoor and/or indoor air. It is important to quantify PM emissions from combustion sources for regulatory and control purposes in relation to air quality. In this paper, we review emission factors for several types of important combustion sources: road transport, industrial facilities, small household combustion devices, environmental tobacco smoke, and vegetation burning. We also review current methods for measuring particle physical characteristics (mass and number concentrations) and principles of methodologies for measuring emission factors. The emission factors can be measured on a fuel-mass basis and/or a task basis. Fuel-mass based emission factors (e.g., g/kg of fuel) can be readily used for the development of emission inventories when the amount of fuels consumed are known. Task-based emission factors (g/mile driven, g/MJ generated) are more appropriate when used to conduct comparisons of air pollution potentials of different combustion devices. Finally, we discuss major shortcomings and limitations of current methods for measuring particle emissions and present recommendations for development of future measurement techniques.     

Monitoring the levels of brominated and organophosphate flame retardants in passenger cars: Utilisation of car air filters as active samplers

Filters in residential and office air conditioning(A/C) systems have been used as sampling devices for monitoring different pollutants.However,cabin air filters(CAFs) in the A/C system of passenger cars have not been utilised for this purpose.In this study,we collected22 used CAFs from passenger cars in Hanoi,Vietnam to analyse for 8 polybrominated diphenyl ethers(PBDEs) and 10 organophosphate esters(OPEs).All the analytes were detected in more than 50% of samples with the exception of BDE153 and BDE154.The average concentrations of ∑_(10)OPEs and ∑_8 BDEs in the captured dust were 2600 and 40 ng/g,respectively with Tris(1-chloro-2-propyl) phosphate(TCIPP) and BDE209 as the dominant congener in OPE and BDE groups,respectively.CAFs are a potential tool to qualitatively assess the levels of semi-volatile chemicals in suspended dust in cars as a screening step for exposure assessment of those chemicals.     

Sorbents with high efficiency for CO2 capture based on amines-supported carbon for biogas upgrading

Sorbents for CO_2 capture have been prepared by wet impregnation of a commercial active carbon(Ketjen-black, Akzo Nobel) with two CO_2-philic compounds, polyethylenimine(PEI)and tetraethylenepentamine(TEPA), respectively. The effects of amine amount(from 10 to70 wt.%), CO_2 concentration in the feed, sorption temperature and gas hourly space velocity on the CO_2 capture performance have been investigated. The sorption capacity has been evaluated using the breakthrough method, with a fixed bed reactor equipped with on line gas chromatograph. The samples have been characterized by N_2 adsorption–desorption,scanning electron microscopy and energy dispersive X-ray(SEM/EDX). A promising CO_2 sorption capacity of 6.90 mmol/gsorbenthas been obtained with 70 wt.% of supported TEPA at 70℃ under a stream containing 80 vol% of CO_2. Sorption tests, carried out with simulated biogas compositions(CH_4/CO_2mixtures), have revealed an appreciable CO_2 separation selectivity; stable performance was maintained for 20 adsorption–desorption cycles.     

Treatment of wastewaters from ore flotation containing aliphatic amines and hydrofluoric acid

Wastewaters from feldspar flotation containing hydrofluoric acid and amines were effectively purified by neutralization‐clarification with a 10% solution of lime and polyelectrolytes, followed by a coke filtration and/or a Zeolite or Activated Alumina adsorption. A Polish synthetic Ca‐type Zeolite proved to be efficient in the elimination of fluoride ions at the pH of 7.8. At this pH the Zeolite was more efficient than the Activated Alumina N. Wastewaters from feldspar washing were effectively treated by coagulation with A1₂(SO₄)₃, yielding final effluents with the characteristics very close to the clarified postilotation wastewaters. After clarification amines and fluoride ions could be removed from feldspar postflotation and feldspar washing effluents mixed together. A final concentration of fluorides and amines in the purified wastewaters was below 2 mg/1.     

Copper, Copper Mining Effluents and Grazing as Potential Determinants of Algal Abundance and Diversity in Northern Chile

We experimentally tested threealternative hypotheses to explain the low algaldiversity and abundance in an intertidal zonereceiving the effluents of the copper mine El Salvadorin northern Chile. Our results demonstrated thatalgae were able to grow at the levels of dissolvedcopper detected in coastal waters of the area. Duringthe assays, growth and regeneration in several red,green and brown adult algae and juvenile Lessonia nigrescens were normal at copper levels of150 g L^-1 or, in some cases, higher. Wealso found that the coastal sea water mixed with theeffluent was not lethal to algae, although in somecases minor effects on growth were detected. Theseresults indicate that today's low algal diversity andabundance can not be explained by the current copperlevels in the area nor by the effect of the effluent.Exclusion of grazers, however, resulted in a fastcolonization by various algal species. This, togetherwith atypically high grazer density at the areas underthe influence of the effluent, strongly suggests thatherbivory, a factor not directly related to the miningoperation, is likely to be responsible for the lowalgal diversity and abundance in the studied locality.