Impact of Different Mineral Reinforcements on HDPE Composites: Effects of Melt Flow Index and Particle Size on Physical and Mechanical Properties.

The use of mineral reinforcements in polymer matrix composites has emerged as an alternative for sustainable production, reducing waste and enhancing the physical and mechanical properties of these materials. This study investigated the impact of the melt flow index (MFI) of HDPE and the particle size of two mineral reinforcements, Bahia Beige (BB) and Rio Grande do Norte Limestone (CRN), on the composites. All composites were processed via extrusion, followed by injection, with the addition of 30 wt.

Organic matter decay and bacterial community succession in mangroves under simulated climate change scenarios.

Mangroves are coastal environments that provide resources for adjacent ecosystems due to their high productivity, organic matter decomposition, and carbon cycling by microbial communities in sediments. Since the industrial revolution, the increase of Greenhouse Gases (GHG) released due to fossil fuel burning led to many environmental abnormalities such as an increase in average temperature and ocean acidification. Based on the hypothesis that climate change modifies the microbial diversity associated with decaying organic matter in mangrove sediments, this study aimed to evaluate the microbial diversity under simulated climate change conditions during the litter decomposition process and the emission of GHG.

Land disposal of dredged sediments from an urbanized tropical lagoon: toxicity to soil fauna.

Urban tropical lagoons are commonly impacted by silting, domestic sewage and industrial wastes and the dredging of their sediments is often required to minimize environmental impacts. However, the ecological implications of land disposal of dredged sediments are still poorly investigated in the tropics. Aiming to contribute to filling this gap, an ecotoxicological evaluation was conducted with dredged sediments from Tijuca Lagoon (Rio de Janeiro, Brazil) using different lines of evidence, including soil and sediment characterization, metal determination, and acute and avoidance bioassays with Eisenia andrei.

A picture of artisanal and small-scale gold mining (ASGM) in Brazil and its mercury emissions and releases.

This study presents a picture of ASGM in Brazil and prospective numbers on mercury emissions and releases in 2016, when the country declared production of about 90 tonnes of gold, of which circa 25 tonnes came from ASGM. However, it is also necessary to consider the illegal production of ASGM which is estimated to vary between 10% and eight times more than the legal production. The proposed method included: organization of spatial data on legal ASGM output, stakeholder identification and meetings, mercury metallurgical balance, quantitative measurement of mercury in the atmosphere and qualitative social aspects such as the miners' economic dependence on the managers and scenarios of illegal ASGM annual production.

Multitechnique Characterization of Pigments Used in Paintings by Léon Pallière.

This study provides a microanalytical characterization of pigment fragments from the painting "Allegory to the Arts" and two portraits, "Rubens" and "Tintoretto," by Léon Pallière. The fragments were surface-analyzed using several near-surface methods to acquire information on the materials and determine the painting techniques utilized before the restoration. Scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM/EDS), Raman spectroscopy coupled to an optical microscope (Raman microprobe), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) revealed organic materials, hydrocerussite (Pb3(CO3)2(OH)2), cerussite (PbCO3), zincite (ZnO), chalcopyrite (CuFeS2), nepheline (K(Na,K)3AlSi4O16), calcite (CaCO3), brookite (TiO2), kinoshitalite (Ba3(Si2Al2)O10(OH)2), hematite (Fe2O3), barium magnesium silicate (Ba2Mg(Si2O7)), and aluminosilicates.

Lithium Separation from Geothermal Brine to Develop Critical Energy Resources Using High-Pressure Nanofiltration Technology: Characterization and Optimization.

There is a shift from internal combustion engines to electric vehicles (EVs), with the primary goal of reducing CO emissions from road transport. Battery technology is at the heart of this transition as it is vital to hybrid and fully electric vehicles' performance, affordability, and reliability. However, it is not abundant in nature.

Role of indigenous microorganisms and organics in the release of iron and trace elements from sediments impacted by iron mine tailings from failed Fundão dam.

After Fundão Dam failure in 2015, most of Gualaxo do Norte River in Doce River Basin in Brazil became silted by iron mining tailings consisting mainly of fine-grained quartz, hematite, and goethite. Previous work pointed to the possibility of reductive dissolution of iron and manganese from tailings, leading to mobilization of iron, manganese and trace elements. Several microorganisms were shown to reduce Fe(III) to Fe(II) and Mn(III, IV) to Mn(II) "in vitro", but their roles in mobilization of Fe and trace elements from freshwater sediments are poorly understood.

Incorporation of Ornamental Stone Waste in the Manufacturing of Red Ceramics.

Brazil is one of the largest producers of ornamental stones in the world. The state of Espírito Santo has considerable social and economic relevance in the production of ornamental stones, particularly in exportation and the jobs that are directly related to this industry. The objectives of this work were to evaluate the effect of the incorporation of ornamental stone waste on the physical and mechanical properties of red ceramic manufactured using clays and waste from the state of Espírito Santo, and to collaborate to regulate the use of this ornamental stone waste in the ceramic industry when manufacturing products.

Fungal succession on the decomposition of three plant species from a Brazilian mangrove.

Leaf decomposition is the primary process in release of nutrients in the dynamic mangrove habitat, supporting the ecosystem food webs. On most environments, fungi are an essential part of this process. However, due to the peculiarities of mangrove forests, this group is currently neglected.

Ecological risk assessment of metal and hydrocarbon pollution in sediments from an urban tropical estuary: Tijuca lagoon (Rio de Janeiro, Brazil).

Urban tropical lagoons are often impacted by eutrophication, metal, and polycyclic aromatic hydrocarbon (PAH) contamination, but the toxicity of their bottom sediments is still poorly investigated in South America. Aiming to contribute to filling this gap, a sediment quality assessment was conducted in the Tijuca Lagoon (Rio de Janeiro, Brazil) using different lines of evidence (LOEs) including sediment characterization, determination of metals and PAHs, and acute toxicity testing with burrowing amphipods (Tiburonella viscana). Mud and organic matter contents played a crucial role in contaminant distribution along the lagoon.

Saccharification of acid-alkali pretreated sugarcane bagasse using immobilized enzymes from .

Unlabelled: In this study, a mild-temperature two-step dilute acid and alkaline pretreatment (DA-AL) process was developed to generate highly digestible cellulose pulp from sugarcane bagasse for producing fermentable sugars by novel thermophilic cellulases derived from SC 04. First, DA pretreatment of sugarcane bagasse at 2% (w/v) HSO and 121 °C for 71 min, followed by AL pretreatment at 2.2% (w/v) NaOH and 110 °C for 100 min led to the pulp containing 86% cellulose.

E-waste mining and the transition toward a bio-based economy: The case of lamp phosphor powder.

Abstract: E-waste contains economically significant levels of precious, critical metals and rare-earth elements (REE), apart from base metals and other toxic compounds. Recycling and recovery of critical elements from E-waste using a cost-effective technology are now among the top priorities in metallurgy due to the rapid depletion of their natural resources. This paper focuses on the perceptions of recovery of REE from phosphor powder from spent fluorescent lamps regarding a possible transition toward a bio-based economy.

The unexplored bacterial lifestyle on leaf surface.

Social interactions impact microbial communities and these relationships are mediated by small molecules. The chemical ecology of bacteria on the phylloplane environment is still little explored. The harsh environmental conditions found on leaf surface require high metabolic performances of the bacteria in order to survive.

Immobilized microbial nanoparticles for biosorption.

Biosorption processes emerge as an economical and eco-friendly alternative technology for the removal of pollutants present in the environment. One biosorption process application is found in the immobilization of microbial cells for the removal of toxic pollutants in industrial wastewater. The immobilization of microorganisms on magnetic nano-based carriers is a relevant new technique applied to obtain biocatalysts for environmental pollution control, however, it has been little described in the literature.

Biosorption as green technology for the recovery and separation of rare earth elements.

Rare earth elements (REE) have great demand for sustainable energy and the high-end technology sector. The high similarity of REE owing to the nature of their electronic configurations increases the difficulty and costs of the development of chemical processes for their separation and recovery. In this way, the development of green technologies is highly relevant for replacing conventional unit operations of extractive metallurgy, viz.

Use of plant materials for the bioremediation of soil from an industrial site.

Bioremediation is one of the existing techniques applied for treating oil-contaminated soil, which can be improved by the incorporation of low-cost nutritional materials. This study aimed to assess the addition of two low-cost plant residues, sugarcane bagasse (SCB) and leaf litter (LL) of the forest leguminous plant (sabiá), either separately or combined, to a contaminated soil from a petroleum refinery area, analyzed after 90 days of treatment. Individually, both amounts of SCB (20 and 40 g kg) favored the growth of total heterotrophic bacteria and total fungi, while LL at 20 g kg better stimulated the hydrocarbon-degrading microorganism's activity in the soil.

Intraspecific variation on epiphytic bacterial community from Laguncularia racemosa phylloplane.

Mangroves are dynamic and unique ecosystems that provide important ecological services to coastal areas. The phylloplane is one of the greatest microbial habitats, and most of its microorganisms are uncultivated under common laboratory conditions. Bacterial community structure of Laguncularia racemosa phylloplane, a well-adapted mangrove species with salt exudation at foliar levels, was accessed through 16S rRNA amplicon sequencing.

Metal pollution in surface sediments from Rodrigo de Freitas Lagoon (Rio de Janeiro, Brazil): Toxic effects on marine organisms.

The Rodrigo de Freitas Lagoon (RFL - Rio de Janeiro, RJ, Brazil) is a highly polluted and eutrophic lacustrine system, which has been often used for the practice of aquatic sports, including during the 2016 Summer Olympic Games. This study proposes the evaluation of metal concentrations in surface sediments from the RFL before and after urban interventions performed for the 2016 Olympics, as well as their toxicity to the benthic amphipod Tiburonella viscana and embryos of the sea-urchin Echinometra lucunter. Metal concentrations determined in 2017 were significantly higher than those obtained in 2015 (especially Cu, Cd and Ni), suggesting that the interventions performed to fulfill the requirements of the Olympics increased metal contents in sediments.

Spatial variability and seasonal toxicity of dredged sediments from Guanabara Bay (Rio de Janeiro, Brazil): acute effects on earthworms.

The toxicity of dredged sediments from Guanabara Bay (Rio de Janeiro, Brazil) was evaluated using acute bioassays with Eisenia andrei and metal determination. The sediments were collected in August 2014 (winter) and February 2015 (summer) and in five areas distributed along the Bay: Port of Rio de Janeiro, Port of Niterói, Meriti River mouth, Iguaçu River mouth, and the Environmental Protection Area (APA) of Guapimirim. The sediments were mixed with a ferralsol (a representative Brazilian tropical soil) in proportions varying between 0 (pure soil) and 30%.

Determination of size-segregated elements in diesel-biodiesel blend exhaust emissions.

This study was based on the determination of metals in particulate matter emitted by a typical diesel engine used by busses and trucks in Brazil. Emissions were sampled using a cascade impactor, and the engine was operated using diesel with 5% (B5), 10% (B10), 15% (B15), and 20% (B20) of biodiesel. The particulate matter was stratified in different sizes, i.

Mass balance of arsenic fluxes in rivers impacted by gold mining activities in Paracatu (Minas Gerais State, Brazil).

Arsenic (As) is a dangerous and carcinogenic element and drinking water is its main pathway of human exposure. Gold mines are widely recognized as important sources of As pollution. This work proposes the assessment of As distribution along watersheds surrounding "Morro do Ouro" gold mine (Paracatu, southeastern Brazil).

Copper extraction from coarsely ground printed circuit boards using moderate thermophilic bacteria in a rotating-drum reactor.

The current work reports on a new approach for copper bioleaching from Printed Circuit Board (PCB) by moderate thermophiles in a rotating-drum reactor. Initially leaching of PCB was carried out in shake flasks to assess the effects of particle size (-208μm+147μm), ferrous iron concentration (1.25-10.

Human exposure and risk assessment associated with mercury contamination in artisanal gold mining areas in the Brazilian Amazon.

Mercury (Hg) contamination is an issue of concern in the Amazon region due to potential health effects associated with Hg exposure in artisanal gold mining areas. The study presents a human health risk assessment associated with Hg vapor inhalation and MeHg-contaminated fish ingestion, as well as Hg determination in urine, blood, and hair, of human populations (about 325 miners and 321 non-miners) from two gold mining areas in the Brazilian Amazon (São Chico and Creporizinho, Pará State). In São Chico and Creporizinho, 73 fish specimens of 13 freshwater species, and 161 specimens of 11 species, were collected for total Hg determination, respectively.

Raman spectroscopic analysis of real samples: Brazilian bauxite mineralogy.

In this investigation, Raman spectroscopy with 1064 and 632.8 nm excitation was used to investigate real mineral samples of bauxite ore from mines of Northern Brazil, together with Raman mapping and X-rays diffraction. The obtained results show clearly that the use of microRaman spectroscopy is a powerful tool for the identification of all the minerals usually found in bauxites: gibbsite, kaolinite, goethite, hematite, anatase and quartz.

Mercury contamination in fish from gold mining areas in Indonesia and human health risk assessment.

This study investigates the effects on fish and assesses human health hazards from mercury released in two gold mining areas in Indonesia: Tatelu (North Sulawesi Province) and Galangan (Katingan District, Central Kalimatan Province). In Tatelu, 154 fish specimens of 10 freshwater species were collected, as well as five marine species from the fish market. The mean concentration of total mercury in muscles of freshwater fish from this area was 0.