ESTUDO DE MEIO REATIVO PARA BARREIRAS REATIVAS PERMEÁVEIS (BRP): ENSAIOS LABORATORIAIS: Study of reactive medium for permeable reactive barriers (PRB): laboratory experiments

This study presents results of laboratory studies to evaluate the assessment of zeolites as a reactive medium of Permeable Reactive Barriers (BRPs) in 3 particle size ranges (4.0x10-4 a 1.0x10-3 m, 1.0x10-3 a 2.0x10-3 m e 1.0x10-3 a 3.0x10-3 m). Studies were developed through physical, chemical, mineralogical, permeability and sorption characterization. The characterized zeolite is Clinoptilolite species, with specific weight of the solids of 22.87 kN/m3, Si/Al ratio of 6.8 and cation exchange capacity of 180 cmolc/kg. The different volumetric arrangements of the particles generated values ​​of dry bulk density ranging from 10.01 to 11.00 kN/m3 and saturated hydraulic conductivities from 1x10-5 to 3x10-4 m/s, which result in arrangements compatible with different geological media. In terms of sorption, Langmuir isotherm adjust with r2 of 0.997 and for the adsorption kinetics, the behavior occurs through the sharing of electrons between zeolite and solute, with first order reaction coefficients ranging from 0.06 to 0.4 h-1 depending on the time of percolation. The results show that the zeolites in the studied particle size ranges are suitable for use as a reactive BRP medium in economically viable thicknesses for contaminated areas inserted in geological materials related to the Botucatu Formation.Esse manuscrito apresenta resultados de estudos laboratoriais para avaliar a adequabilidade de zeólitas como meio reativo de Barreiras Reativas Permeáveis (BRPs), em 3 faixas granulométricas (4,0x10-4 a 1,0x10-3 m, 1,0x10-3 a 2,0x10-3 m e 1,0x10-3 a 3,0x10-3 m). Estudos foram desenvolvidos por meio da caracterização física, química, mineralógica, permeabilidade e de sorção. A zeólita caracterizada é da espécie Clinoptilolita, com peso específico dos sólidos de 22,87 kN/m3, razão Si/Al de 6,8 e capacidade de troca catiônica de 180 cmolc/kg. Os diferentes arranjos volumétricos das partículas geraram valores de peso específico aparente seco de 10,01 a 11,00 kN/m3 e condutividades hidráulica saturada de 1x10-5 a 3x10-4 m/s, o que compatibiliza os arranjos com diferentes meios geológicos. Em termos de sorção, a isoterma do tipo Langmuir ajusta com r2 de 0,997 e, quanto a cinética de adsorção, o comportamento ocorre por meio do compartilhamento de elétrons entre zeólita e soluto, com coeficientes de reação de primeira ordem variando de 0,06 a 0,4h-1 em função do tempo de percolação. Os resultados mostram que as zeólitas nas faixas granulométricas estudadas são adequadas para uso como meio reativo de BRP em espessuras economicamente viáveis para áreas contaminadas inseridas em materiais geológicos relativos à Formação Botucatu

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

Geotechnical and physical-chemical aspects in permeable reactive barriers: laboratory studies

Esta pesquisa apresenta um estudo laboratorial sobre a aplicação de zeólitas da espécie clinoptilolita como reator em barreiras reativas permeáveis (BRPs). A metodologia experimental consistiu, primeiramente, na caracterização física, química, mineralógica e físico-química desse mineral em três faixas granulométricas distintas, que em seguida, foi avaliado quanto às suas características geotécnicas, hidráulicas, capacidade de adsorção para os elementos K+, Zn2+ e Cl- e regeneração, por meio de ensaios de batch test, cinéticos, de condutividade hidráulica, percolação de solução contaminante e flushing. Os resultados obtidos foram integrados para determinação do arranjo mais apropriado para esse tipo de barreira, como também, para obtenção dos parâmetros de transporte de contaminantes e de sorção na zeólita. Para ajuste das isotermas de adsorção foram utilizados os modelos Linear, de Freundlich e Langmuir. Os dados obtidos por meio dos estudos cinéticos foram ajustados conforme os modelos de pseudo-primeira ordem, pseudo-segunda ordem e Elovich. Para ambos os casos, os modelos de Langmuir e pseudo-segunda ordem foram os que melhor representaram o processo de adsorção da clinoptilolita (r2 > 0,99). Os resultados indicam que a zeólita clinoptilolita apresenta elevada capacidade de adsorção para os íons analisados, exibindo a seguinte ordem de seletividade: K+ > Zn2+. Por outro lado, a eficiência de lavagem do material se revelou muito baixa, indicando que o material é apropriado para sistemas de BRPs com reatores trocáveis. De uma forma geral, o material analisado apresenta potencial satisfatório para o uso em barreiras reativas permeáveis na remediação de águas subterrâneas contaminadas.This research presents a laboratory study on the application of clinoptilolite zeolite specie as the reactor in permeable reactive barriers (PRBs). The experimental methodology consisted firstly in the physical, chemical, mineralogical and physical-chemical characterization of this mineral in three distinct grain sizes, which were then evaluated for their geotechnical, hydraulic, adsorption capacity of K+, Zn2+ and Cl- and regeneration features, through experiments as batch test, kinetic, hydraulic conductivity, contaminant solution percolation and flushing. The results obtained were integrated to determine the most appropriate arrangement for this type of barrier, as well as to obtain the contaminant transport and sorption parameters through zeolite. To adjust the adsorption isotherms, Linear, Freundlich and Langmuir models were used. The data obtained through the kinetic studies were adjusted according to the pseudo-first-order, pseudo-second order and Elovich models. In both cases, the Langmuir and pseudo-second order models were the ones that best represented the adsorption process of clinoptilolite (r2 > 0.99). The results indicated that the zeolite clinoptilolite presents high adsorption capacity for the analyzed ions, showing the following order of selectivity: K+ > Zn2+. On the other hand, the washing efficiency of the material has proved to be very low, indicating that the material is suitable for PRB systems with exchangeable reactors. In general, the analyzed material presents satisfactory potential for use in permeable reactive barriers in the remediation of contaminated groundwater

Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies

The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmolc/kg and a high K+ adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r2 > 0.999) for both K+ and Zn2+ cations. Additionally, the contaminant transport parameters for K+ ions (Rd = 24.9; Dh = 1.32 × 10–2 cm2/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data