Thursday 17 December 2015

Forecasting Olea Airborne Pollen Concentrations by Means of Artificial Intelligence

Fresenius Environmental Bulletin, (2015) 24, 4574-4580


A model based in an Artificial Neural Network was de- veloped in order to forecast the Olea airborne pollen concen- tration due to the allergenic power of its pollen grains. Daily data for Olea pollen and the meteorological variables docu- mented in the period 1993-2008, were used. All developed models had five input variables; i) Julian day, ii) precipita- tion, iii) humidity value, and iv) insolation hours. The model was carried out with data collected in the city of Ourense, North West of Spain. The developed model predicts the at- mospheric concentration of Olea pollen one day ahead. The model was tested with data from 2009 and 2010. The devel- oped model could be employed in allergology and health sci- ences in order to prevent effect of pollinosis. It is due the ability of obtain good predictions of threshold pollen con- centration values, which are important to take preventive measures by Health Systems. The time-lag observed in pre- diction phase may be due to the influence of other meteoro- logical parameters which have not been taken into account in the beginning, this fact is reaffirmed by studying the simi- larity between the different pollen seasons and the year 2010 (Mann-Whitney U Test with p<0.031), or due the low concen- trations of Olea pollen during the MPS (≈ 14 grains·m-3).

Thursday 10 December 2015

Organic pollutants profiling of wood ashes from biomass power plants linked to the ash characteristics

Science of the Total Environment, 544 (2016) 535-543
doi:10.1016/j.scitotenv.2015.11.134



Wood ash, characterized by high content of certain nutrients and charcoal, can be applied to soils as a means of managing this waste product improving the soil quality. The associated environmental risk must be assessed. The objective of this study was to characterize the bottom and fly ash collected from 15 biomass power plants in Spain by determining the benzene, toluene, ethylbenzene, xylene and styrene (BTEX + S), PAHs and aliphatic hydrocarbon contents of both types of ash. Biochar was also used for comparison purposes.

Wednesday 9 December 2015

As(V) and P Competitive Sorption on Soils, By-Products and Waste Materials

Int. J. Environ. Res. Public Health 2015, 12(12), 15706-15715
doi:10.3390/ijerph121215016


Batch-type experiments were used to study competitive As(V) and P sorption on various soils and sorbent materials. The materials assayed were a forest soil, a vineyard soil, pyritic material, granitic material, coarsely and finely ground mussel shell, calcinated mussel shell ash, pine sawdust and slate processing fines. Competition between As(V) and P was pronounced in the case of both soils, granitic material, slate fines, both shells and pine sawdust, showing more affinity for P. Contrary, the pyritic material and mussel shell ash showed high and similar affinity for As(V) and P. These results could be useful to make a correct use of the soils and materials assayed when focusing on As and P removal in solid or liquid media, in circumstances where both pollutants may compete for sorption sites.

Monday 7 December 2015

Electrical Percolation of AOT-based Microemulsions with n-Alcohols

Journal of Molecular Liquids
DOI: 10.1016/j.molliq.2015.12.021


Percolative behaviour of w/o AOT/iC8/H2O microemulsions added with different n-alkanols is reported. 1-n-alcohols and 2-n-alkanols presented dissimilarities affecting percolation. Smaller alcohols ease percolation, especially at low concentrations. Greater molecules implied a reinforcement of the surfactant film that delayed percolation threshold. Also, a neural network based simulation model of the phenomenon has been developed. This single model has only five input variables and can estimate percolation temperature of microemulsions added with the two types of alcohols studied, with an RMSE of 0.98oC and R2=0.9740 (validation dataset values). This is considered a successful prediction rate, following previous developments with other families of additives, that confirms neural networks as reliable tools for percolative behaviour modelling.

Thursday 3 December 2015

A palla de cereal reinvéntase como material de última xeración para producir nanofibras de celulosa


  • Investigadores das universidades de Córdoba e Vigo desenvolven novos usos para estes residuos a través de novas novas técnicas de separación ambientalmente favorables.


A industria agroalimentaria enfróntase ao reto de xestionar os seus residuos e faino, entre outras liñas de actuación, buscando a través da I+D novos usos para os subprodutos que xera. É o caso da palla de cereal. Os cambios nos usos dos terreos agrícolas, máis orientados actualmente á obtención de alimentos e de biocombustible, traen consigo a necesidade e a oportunidade de aproveitar os residuos de cultivos de cereais como o trigo, a cebada ou a avea. Investigadores da Universidade de Vigo colaboran nun proxecto da Universidade de Córdoba que traballa na obtención de nanofibras de celulosa, actualmente obtidas principalmente de especies madereiras, destes residuos agrícolas. 

Os resultados desta investigación conxunta veñen de ser publicados na revista Bioresource Technology, nun artigo titulado Agricultural residue valorization using a hydrothermal process for second generation bioethanol and oligosaccharides production e asinado por F. Vargas, E. Domínguez, C. Vila, A. Rodríguez Pascual e Gil Garrote, investigador este último da Facultade de Ciencias do campus de Ourense. Segundo explican os científicos do equipo de investigación Biorrefinería de Materiais Lignocelulósicos da Industria Agroalimentaria da Universidade de Córdoba, liderado por Alejandro Rodríguez, a celulosa é un dos polímeros máis dispoñibles do planeta pola súa presenza nos vexetais. Este grupo ten unha ampla bagaxe na obtención de papel e cartón a partir da celulosa, buscando agora novos procedementos químicos para obter máis produtos e de maior valor engadido, como hidroxeles ou compoñentes para a formulación de cemento.


Obtención de azucres e biocombustible

Entre estes procedementos está a biorrefinería de materiais lignocelulosos, que permite separar nos residuos agrícolas como a palla de cereal a celulosa, a hemicelulosa e a lignina. O primeiro material é aproveitable directamente para facer papel desde a celulosa chamada nobre, mentres que coas hemicelulosas obtéñense compostos de interese industrial, como por exemplo xilitol. Por último, está a lignina, que está presente na chamada lixivia negra ou licor residual. A colaboración coa Universidade de Vigo permitiu desenvolver novas técnicas na separación da celulosa e a lignina. O proceso, de carácter innovador, disolve a materia prima cun catalizador ácido, obtendo unha fracción rica en hemicelulosas e outra rica en celulosa e lignina. A partir desta fracción líquida caracterizáronse azucres interesantes para a industria alimentaria, como xilitol. A fracción sólida, rica en celulosa, púidose fermentar para a obtención de biocombustibles. 

Segundo comenta Rodríguez Pascual, “a palla do cereal ata o de agora empregábase para alimentar o gando ou se desbotaba no campo, en ocasións por medio de pequenos lumes controlados”. O procedemento desenvolvido durante a investigación parte dun proceso ambientalmente favorable, ao empregar sosa a presión atmosférica. Así obtéñense fibras celulósicas por un lado, que se utilizarán para a obtención de lignonanofibras de celulosa (con aparencia de xel), e o licor negro, rico en lignina, por outro. Os investigadores están obtendo lignonanofibras de celulosa mediante procedementos mecánicos, enzimáticos e por oxidación TEMPO, partindo da pasta celulósica sen branquexar, o que implica un menor custe económico e ambiental respecto a outras nanofibras que se obteñen mediante un proceso previo de blanqueamiento.

Fuente: DUVI