Hydrothermal synthesized kaolin group lamellar/spongy aluminosilicates for enhanced lead vapor capture.

Developing high-temperature-resistant adsorbents with superior porous properties is crucial for safely disposing of heavy metal-containing solid waste via pyrolysis. We synthesized aluminosilicates hydrothermally and observed that acidic conditions, especially HCl (pH=2.6), favored sponge-like mineral (NC2.6) formation with a specific surface area of 500.31 m²/g and pore volume of 0.986 cm³ /g, while alkaline conditions (pH=12.0) promoted spherical particle growth. NC2.6 exhibited higher adsorption capacity compared to kaolinite and halloysite in the PbCl2 vapor adsorption, reaching a maximum of 137.68 mg/g at 700 â„ƒ (75.91 % stable). We examined the effect of CO2 and H2O on adsorption efficiency and explored the mechanisms using DFT and GCMC simulations. From GCMC results, CO2 negatively impacted PbCl2 adsorption due to competitive adsorption, while H2O increased adsorption content (144.24 mg/g at 700 â„ƒ) by converting PbCl2 into oxides. DFT revealed the presence of CO2 enhanced the adsorption stability of PbCl2 via the formation of covalent bonds between O in CO2 and Pb, and active O on the aluminosilicate surface. H2O increased PbCl2 adsorption energy, as O in H2O occupied an active Al that originally formed a covalent bond with Cl, while the H formed a weak hydrogen bond with this Cl.

Aluminosilicates-based nanosorbents for heavy metal removal - A review.

Contamination of water bodies with heavy metals poses a significant threat to human health and the environment, requiring the development of effective treatment techniques. In this context, aluminosilicates emerge as promising sorbents due to their cost-effectiveness and natural abundance. This review provides a clear, in-depth, and comprehensive description of the structure, properties, and characteristics of aluminosilicates, supporting their application as adsorbents and highlighting their diversity and adaptability to different matrices and analytes. Furthermore, the functionalization of these materials is thoroughly addressed, detailing the techniques currently used, exposing the advantages and disadvantages of each approach, and establishing comparisons and evaluations of the performances of various functionalized aluminosilicates in the extraction of heavy metals in aqueous matrices. This work aims not only to comprehensively review numerous studies from recent years but also to identify trends in the study of such materials and inspire future research and applications in the field of contaminant removal using aluminosilicates.

Clay-reinforced PVC composites and nanocomposites.

Clay-reinforced polyvinyl chloride (PVC) composites and nanocomposites are one of the newest and most important compounds studied and used in various applications, including the biomedical, automotive industry, water treatment, packaging, fire retarding, and construction. The most important clays used in the synthesis of these composites are Bentonite, Montmorillonite, Kaolinite, and Illite. The addition of these nanoclays to the PVC matrix improves mechanical properties, thermal stability, and yellowness index properties. In this chapter, a detailed study of PVC and its properties, types of nanoclays and their properties, modification of nanoclays, production methods of composites, and nanocomposites of PVC/clay, their characterization, and applications have been performed. Herein, the types, properties, and applications of PVC/clay nanocomposites, as well as their challenges and future remarks, are reviewed.

Exploring zeolite-based composites in adsorption and photocatalysis for toxic wastewater treatment: Preparation, mechanisms, and future perspectives.

Water scarcity has become a critical global concern exacerbated by population growth, globalization, and industrial expansion, resulting in the production of wastewater containing a wide array of contaminants. Tackling this challenge necessitates the adoption of innovative materials and technologies for effective wastewater treatment. This review article provides a comprehensive exploration of the preparation, applications, mechanisms, and economic environmental analysis of zeolite-based composites in wastewater treatment. Zeolite, renowned for its versatility and porous nature, is of paramount importance due to its exceptional properties, including high surface area, ion exchange capability, and adsorption capacity. Various synthetic methods for zeolite-based composites are discussed. The utilization of zeolites in wastewater treatment, particularly in adsorption and photocatalysis, is thoroughly investigated. The significance of zeolite in adsorption and its role in the photocatalytic degradation of pollutants are examined, along with its applications in treating volatile organic compounds (VOCs), dye wastewater, oil-field wastewater, and radioactive waste. Mechanisms underlying zeolite-based adsorption and photocatalysis, including physical and chemical adsorption, ion exchange, and surface modification, are elucidated. Additionally, the role of micropores in the adsorption process is explored. Furthermore, the review delves into regeneration and desorption studies of zeolite-based composites, crucial for sustainable wastewater treatment practices. Economic and environmental analyses are conducted to assess the feasibility and sustainability of employing zeolite-based composites in wastewater treatment applications. Future recommendations are provided to guide further research and development in the field of zeolite-based composites, aiming to enhance wastewater treatment efficiency and environmental sustainability. By exploring the latest advancements and insights into zeolite-based nanocomposites, this paper aims to contribute to the development of more efficient and sustainable wastewater treatment strategies. The integration of zeolite-based materials in wastewater treatment processes shows promise for mitigating water pollution and addressing water scarcity challenges, ultimately contributing to environmental preservation and public health protection.

Effect of zeolites on the reduction of the ecotoxicity of carbamazepine in the environment.

In this study, the impact of calcination of zeolites on the ecotoxicity of carbamazepine solutions in two matrices, water and synthetic sewage, was assessed. Two types of zeolites were tested: natural zeolite, in the form of a zeolite rock consisting mainly of clinoptilolite, and a synthetic zeolite type 5 A. Additionally, zeolites were calcined at a temperature of 200 °C. The kinetics of carbamazepine adsorption in aqueous solutions and in synthetic sewage matrix was determined. Higher adsorption capacity was obtained for carbamazepine aqueous solutions as well as zeolites after the calcination process. Considering type of zeolite, the highest and fastest uptake of carbamazepine was observed for natural zeolite after calcination. In the case of ecotoxicity, carbamazepine solutions before adsorption was the most toxic towards Raphidocelis subcapitata, next Aliivibrio fischeri and Daphnia magna, regardless to the matrix type. The differentiation in toxicity regarding the type of matrix was observed, in the case of algae and bacteria, higher toxicity was demonstrated by carbamazepine solutions in the water matrix, while in the case of crustaceans-the sewage matrix. After the adsorption process, the toxicity of carbamazepine solutions on zeolites decreased by 34.5-60.9 % for R. subcapitata, 33-39 % for A. fischeri and 55-60 % for D. magna, thus confirming the effectiveness of the proposed method of carbamazepine immobilization.

Newly Generated Ca-Feldspar during Sintering Processes Enhances the Mechanical Strength of Coal Gangue-Based Insulation Bricks.

Coal gangue is a solid waste with low carbon content discharged during the course of the coal mining process. The resource utilization of coal gangue could solve environmental problems caused by its excessive production, such as soil contamination and land occupation. This study proposed to produce high-strength thermal insulation bricks using coal gangue as the primary material and three other mineral powders as auxiliary materials, including K-feldspar, CaCO3 and fly ash. A systematic analysis was conducted to explore the optimum raw material addition ratio and optimum sintering temperature; then, the intrinsic structure of thermal insulation bricks and their sintering formation mechanisms were revealed. The results showed that the optimal ratios of coal gangue, K-feldspar, CaCO3 and fly ash were 65 wt%, 15 wt%, 10 wt% and 10 wt%, respectively; the compressive strength of the thermal insulation brick produced under this ratio was 22.5 MPa; thermal conductivity was 0.39 W m-1 k-1. During sintering processes, mineral powders sufficiently fused to form a skeleton, and the CO2 derived from CaCO3 formed pores. The optimum sintering temperature was 1150 °C, because at this temperature, K-feldspar had the best effect in promoting the conversion of CaCO3 to Ca-feldspar. The high level of the relative crystallinity of Ca-feldspar (about 76.0%) helped raise the Si-O network's polymerization degree (NBO/T = 1.24), finally raising the compressive strength of thermal insulation bricks. The innovative method of using coal gangue to make thermal insulation bricks not only solved the environmental pollution caused by coal gangue but also provided excellent construction materials with high practical application value.

Direct Experimental Observations of Ion Distributions during Overcharging at the Muscovite-Water Interface by Adsorption of Rb+ and Halides (Cl- , Br- , I- ) at High Salinity.

Classical electric double layer (EDL) models have been widely used to describe ion distributions at charged solid-water interfaces in dilute electrolytes. However, the chemistry of EDLs remains poorly constrained at high ionic strength where ion-ion correlations control non-classical behavior such as overcharging, i. e., the accumulation of counter-ions in amounts exceeding the substrate's surface charge. Here, we provide direct experimental observations of correlated cation and anion distributions adsorbed at the muscovite (001)-aqueous electrolyte interface as a function of dissolved RbBr concentration ([RbBr]=0.01-5.8 M) using resonant anomalous X-ray reflectivity. Our results show alternating cation-anion layers in the EDL when [RbBr]≳100 mM, whose spatial extension (i. e., ~20 Šfrom the surface) far exceeds the dimension of the classical Stern layer. Comparison to RbCl and RbI electrolytes indicates that these behaviors are sensitive to the choice of co-ion. This new in-depth molecular-scale understanding of the EDL structure during transition from classical to non-classical regimes supports the development of realistic EDL models for technologies operating at high salinity such as water purification applications or modern electrochemical storage.

Magnetic mining waste based-geopolymers applied to catalytic reactions with ozone.

The demand for sustainable and low-cost materials for wastewater treatment is increasing considerably. In this scenario, geopolymers have gained great interest, due to their good mechanical properties, their ability to be produced from industrial waste and their adsorbent or catalytic properties. In this study, novel magnetic mining waste based-geopolymers were produced by incorporating a residue from phosphate waste rocks, which were extensively characterized (XRD, TGA/DTA, SEM, BET, XRF, FTIR, Mössbauer, ss-NMR and XPS). The materials produced showed formation of a dense framework, even with 75% incorporation of the residue. The iron oxides and their magnetic properties remained unchanged, and their application in advanced oxidation reactions were evaluated, in particular, as catalysts in ozonation reactions. All of the geopolymers presented catalytic activity in the ozonation reaction, with catalytic ozone decomposition values of up to 2.98 min-1, which is 99 times greater than non-catalyzed reactions. Moreover, the reuse (performed in three cycles) and hot filtration-like experiments demonstrated, respectively, the regenerability and heterogeneous catalytic properties of the produced materials, showcasing the potential of these waste materials for catalytic geopolymer production. demonstrating the potential of this waste to produce catalytic geopolymers.

Highly Cooperative CO2 Adsorption via a Cation Crowding Mechanism on a Cesium-Exchanged Phillipsite Zeolite.

An understanding of the CO2 adsorption mechanisms on small-pore zeolites is of practical importance in the development of more efficient adsorbents for the separation of CO2 from N2 or CH4 . Here we report that the CO2 isotherms at 25-75 °C on cesium-exchanged phillipsite zeolite with a Si/Al ratio of 2.5 (Cs-PHI-2.5) are characterized by a rectilinear step shape: limited uptake at low CO2 pressure (PCO2 ) is followed by highly cooperative uptake at a critical pressure, above which adsorption rapidly approaches capacity (2.0 mmol g-1 ). Structural analysis reveals that this isotherm behavior is attributed to the high concentration and large size of Cs+ ions in dehydrated Cs-PHI-2.5. This results in Cs+ cation crowding and subsequent dispersal at a critical loading of CO2 , which allows the PHI framework to relax to its wide pore form and enables its pores to fill with CO2 over a very narrow range of PCO2 . Such a highly cooperative phenomenon has not been observed for other zeolites.

Analytical Review of Geopolymer Concrete: Retrospective and Current Issues.

The concept of sustainable development provides for the search for environmentally friendly alternatives to traditional materials and technologies that would reduce the amount of CO2 emissions into the atmosphere, do not pollute the environment, and reduce energy costs and the cost of production processes. These technologies include the production of geopolymer concretes. The purpose of the study was a detailed in-depth analytical review of studies of the processes of structure formation and properties of geopolymer concretes in retrospect and the current state of the issue. Geopolymer concrete is a suitable, environmentally friendly and sustainable alternative to concrete based on ordinary Portland cement (OPC) with higher strength and deformation properties due to its more stable and denser aluminosilicate spatial microstructure. The properties and durability of geopolymer concretes depend on the composition of the mixture and the proportions of its components. A review of the mechanisms of structure formation, the main directions for the selection of compositions and processes of polymerization of geopolymer concretes has been made. The technologies of combined selection of the composition of geopolymer concrete, production of nanomodified geopolymer concrete, 3D printing of building structures from geopolymer concrete, and monitoring the state of structures using self-sensitive geopolymer concrete are considered. Geopolymer concrete with the optimal ratio of activator and binder has the best properties. Geopolymer concretes with partial replacement of OPC with aluminosilicate binder have a denser and more compact microstructure due to the formation of a large amount of calcium silicate hydrate, which provides improved strength, durability, less shrinkage, porosity and water absorption. An assessment of the potential reduction in greenhouse gas emissions from the production of geopolymer concrete compared to the production of OPC has been made. The potential of using geopolymer concretes in construction practice is assessed in detail.

Extraordinary Acceleration of an Electrophilic Reaction Driven by the Polar Surface of 2D Aluminosilicate Nanosheets.

To increase chemical reaction rates, general solutions include increasing the concentration/temperature and introducing catalysts. In this study, the rate constant of an electrophilic metal coordination reaction is accelerated 23-fold on the surface of layered aluminosilicate (LAS), where the reaction substrate (ligand molecule) induces dielectric polarization owing to the polar and anionic surface. According to the Arrhenius plot, the frequency factor (A) is increased by almost three orders of magnitude on the surface. This leads to the conclusion that the collision efficiency between the ligands and metal ions is enhanced on the surface due to the dielectric polarization. This is surprising because one side of the ligand is obscured by the surface, so the collision efficiency is expected to be decreased. This unique method to accelerate the chemical reaction is expected to expand the range of utilization of LASs, which are chemically inert, abundant, and environmentally friendly. The concept is also applicable to other metal oxides which have polar surfaces, which will be useful for various chemical reactions in the future.

Coarse-Grained Monte Carlo Simulations with Octree Cells for Geopolymer Nucleation at Different pH Values.

Geopolymers offer a potential alternative to ordinary Portland cement owing to their performance in mechanical and thermal properties, as well as environmental benefits stemming from a reduced carbon footprint. This paper endeavors to build upon prior atomistic computational work delving deeper into the intricate relationship between pH levels and the resulting material's properties, including pore size distribution, geopolymer nucleate cluster dimensions, total system energy, and monomer poly-condensation behavior. Coarse-grained Monte Carlo (CGMC) simulation inputs include tetrahedral geometry and binding energy parameters derived from DFT simulations for aluminate and silicate monomers. Elevated pH values may can alter reactivity and phase stability, or, in the structural concrete application, may passivate the embedded steel reinforcement. Thus, we examine the effects of pH values set at 11, 12, and 13 (based on silicate speciation chemistry), investigating their respective contributions to the nucleation of geopolymers. To simulate a larger system to obtain representative results, we propose the numerical implementation of an Octree cell. Finally, we further digitize the resulting expanded structure to ascertain pore size distribution, facilitating a comparative analysis. The novelty of this study is underscored by its expansion in both system size, more accurate monomer representation, and pH range when compared to previous CGMC simulation approaches. The results unveil a discernible correlation between the number of clusters and pores under specific pH levels. This links geopolymerization mechanisms under varying pH conditions to the resulting chemical properties and final structural state.

Fly Ash-Based Geopolymer Composites: A Review of the Compressive Strength and Microstructure Analysis.

Geopolymer (GP) concrete is a novel construction material that can be used in place of traditional Portland cement (PC) concrete to reduce greenhouse gas emissions and effectively manage industrial waste. Fly ash (FA) has long been utilized as a key constituent in GPs, and GP technology provides an environmentally benign alternative to FA utilization. As a result, a thorough examination of GP concrete manufactured using FA as a precursor (FA-GP concrete) and employed as a replacement for conventional concrete has become crucial. According to the findings of current investigations, FA-GP concrete has equal or superior mechanical and physical characteristics compared to PC concrete. This article reviews the clean production, mix design, compressive strength (CS), and microstructure (Ms) analyses of the FA-GP concrete to collect and publish the most recent information and data on FA-GP concrete. In addition, this paper shall attempt to develop a comprehensive database based on the previous research study that expounds on the impact of substantial aspects such as physio-chemical characteristics of precursors, mixes, curing, additives, and chemical activation on the CS of FA-GP concrete. The purpose of this work is to give viewers a greater knowledge of the consequences and uses of using FA as a precursor to making effective GP concrete.

Safe disposal of hazardous waste incineration fly ash: Stabilization/solidification of heavy metals and removal of soluble salts.

Hazardous waste incineration fly ash (HFA) is considered a hazardous waste owing to the high associated concentrations of heavy metals and soluble salts. Hence, cost effective methods are urgently needed to properly dispose HFA. In this study, geopolymers were prepared by alkali-activation technology to stabilize and solidify heavy metals in HFA. In addition, the effects of three different aluminosilicates (metakaolin, fly ash, and glass powder) on the heavy metal immobilization efficiency were investigated. Because the soluble salt content of HFA is too high for their direct placement in flexible landfill sites and water washing can lead to heavy metal leaching, water-washing experiments were conducted after alkali-activation treatment to remove soluble salts. The results suggest that the concentrations of heavy metals leached from geopolymers can satisfy the Chinese Standard limits (GB18598-2019) when the addition of aluminosilicates exceeds 20 wt%. More than 77% of Cl- and >64% of SO42- in geopolymers could be removed via water-washing treatment. The Zn leaching concentration was maintained below approximately 0.52 ppm. After alkali-activation treatment, the water-washing process could efficiently remove soluble salts while inhibiting heavy metal leaching. Sodium-aluminosilicate-hydrate (N-A-S-H) gel, a product of the geopolymerization process in this study, was demonstrated to act as a protective shell that inhibited heavy metal leaching. Hence, HFA-based geopolymers are considered suitable for disposal in flexible landfills.

The structural origin of the efficient photochromism in natural minerals.

SignificanceNatural photochromic minerals have been reported by geologists for decades. However, the understanding of the photochromism mechanism has a key question still unanswered: What in their structure gives rise to the photochromism's reversibility? By combining experimental and computational methods specifically developed to investigate this photochromism, this work provides the answer to this fundamental question. The specific crystal structure of these minerals allows an unusual motion of the sodium atoms stabilizing the electronic states associated to the colored forms. With a complete understanding of the photochromism mechanism in hand, it is now possible to design new families of stable and tunable photochromic inorganic materials-based devices.

Synthesis and Characterization of Spent Bleaching Clay-based Geopolymer: An Effort towards Palm Oil Industry Waste Reutilization.

Spent bleaching clay (SBC) is a problematic waste from the palm oil industry with worldwide availability. In this study, geopolymer was synthesized from SBC, a kind of aluminosilicate material with an alkaline activator solution that is made up of sodium hydroxide and sodium silicate. Calcium silicate (CS), which is a by-product of the silicates removal from wastewater, was also added to the formulation. The geopolymer mixture paste was cured in an oven at 80 °C for 24 h and at room temperature for 7 days. The characterizations were carried out using FTIR spectroscopy, SEM/EDX, TGA, BET, and XRD. The SEM images showed an aggregate of aluminosilicate material is formed with some unreacted particles on the surface of the geopolymer. The TGA results show that the geopolymers decomposed at a higher temperature than SBC, demonstrating its heat resistance properties. The BET results showed the addition of CS formed a denser geopolymer with a total pore volume of 0.0636 cm3 /g.

Structural characterization of interfaces in silica core-alumina shell microspheres by solid-state NMR spectroscopy.

Atomic-scale description of surfaces and interfaces in core-shell aluminosilicate materials is not fully elucidated, partially due to their amorphous character and complex mechanisms that govern their properties. In this paper, new insights into nanostructured core-shell aluminosilicates have been demonstrated, by using different solid-state NMR methods, i.e 29Si, 29Si cross-polarization (CP), 27Al, 27Al triple-quantum (3Q), and 1H-27Al heteronuclear correlation (HETCOR) MAS NMR. For this purpose, nanostructured silica core-alumina shell microspheres, undoped and doped with gadolinium ions respectively, obtained by a chemical synthesis based on the Stöber method for the silica core and electrostatic attraction for developing the alumina shell were studied. As a result, a new alumino-silicate layer formation was proved at the interface between silica core, where aluminum diffuses, on small scale, in the silica network, and alumina shell, where silicon ions migrate, on a larger scale, in the alumina network, leading to a stable core-shell structure. Moreover, this process is accompanied by significant local structural changes in the transition zone, particularly at the aluminum neighborhood, which is quite well understood now, with the power of solid-state NMR spectroscopy.

Efecto de los Tratamientos de Calcinación y Pirólisis sobre la Estructura de Aluminosilicatos de Litio Dopadas con CuO / Effect of the Treatments of Calcination and Pyrolysis on the Structure of Aluminosilicate of Lithium Doped with CuO / Efeito dos Tratamentos de Calcinação e Pirólise na Estrutura de Aluminosilicatos de Lítio Dopadas com CUO

Resumen Introducción: Este artículo reporta la síntesis y caracterización de polvos vitrocerámicos del sistema Li2OAl2O3SiO2 (LAS), dopados con 0.5% y 1 % p/p de óxido de cobre (CuO), como una primera etapa pensando en su posterior evaluación como material termoluminiscente (TL) y su posible aplicación como dosímetro TL. Objetivo: Evaluar el efecto de los tratamientos de calcinación y pirolisis de los geles secos de aluminosilicatos de litio dopados con CuO, obtenidos mediante síntesis Sol-Gel. Materiales y Métodos: Las matrices puras y dopadas con CuO se obtuvieron mediante la verificación de formiatos de aluminio y litio, en presencia de tetraetoxisilano y CuO. Los geles obtenidos se secaron a 120 °C y 2,5 h. La mitad de la cantidad obtenida se sometió a un tratamiento de calcinación (480 °C, 5 h) mientras que la otra mitad se sometió a un proceso de pirolisis (atmósfera de nitrógeno) a 480 °C por 5 h. Las muestras obtenidas se caracterizaron por microscopía electrónica de barrido (SEM), espectroscopia infrarroja (FTIR), potencial zeta y difracción de rayos X (DRX). Resultados: mediante el análisis SEM se confirmó el tamaño de partícula micrométrica, de los espectros se observan algunas bandas prominentes entre Si-O u Al-O, además se asume que los tratamientos térmicos fueron adecuados para la liberación de grupos remanentes orgánicos. Conclusiones: La síntesis implementada permitió la obtención de partículas micrométricas (φp < 25 μm). Los tratamientos térmicos tuvieron un efecto significativo sobre la funcionalización superficial de las partículas obtenidas, y la composición del material y se verificó que la temperatura empleada fue adecuada para la liberación de remanentes orgánicos, además con los espectros se observó los grupos remanentes funcionales que estaban presentes en el material.

Abstract Introduction. This article reports the synthesis and characterization of the glass-ceramic powders of the Li2OAl2O3SiO2 (LAS) system, doped with 0.5% and 1% w / w copper oxide (CuO), as a first stage thinking about its subsequent evaluation as a thermoluminescent material (TL) and its possible application as a TL dosimeter. Objective. To evaluate the effect of the calcination and pyrolysis treatments of the dry gels of lithium aluminosilicates doped with CuO, obtained by Sol - Gel synthesis. Materials and Methods. The pure and doped CuO LAS matrices were obtained by the gelation of lithium aluminum formats, in the presence of tetraethoxysilane and CuO. The gels obtained were dried at 120 ° C and 2.5 h. Half of the amount obtained was subjected to a calcination treatment (480 °C, 5 h) while the other half was subjected to a pyrolysis process (nitrogen atmosphere) at 480 °C for 5 h. The samples obtained were characterized by scanning electron microscopy (SEM), infrared spectroscopy (FTIR), zeta potential and X-ray diffraction (XRD). Results. By means of the SEM analysis the micrometric particle size was confirmed, from the spectra some prominent bands are observed between Si-O or Al-O, besides it is assumed that the thermal treatments were suitable for the release of organic rebasing groups. Conclusions. The synthesis implemented allowed the obtaining of micrometric particles (φp < 25 μm). The thermal treatments had a significant effect on the superficial functionalization of the particles obtained, and the composition of the material and it was verified that the temperature used was adequate for the release of organic reagents, in addition with the spectra we observed the functional rebar groups that were present in the material.

Resumo Introdução: Este artigo relata a síntese e caracterização dos pós vitrocerâmicos do sistema Li2OAl2O3SiO2 (LAS), dopado com 0,5% e 1% p / p de óxido de cobre (CuO), como uma primeira etapa, pensando em sua posterior avaliação como material termoluminescente (TL). e sua possível aplicação como um dosímetro TL. Objetivo: Avaliar o efeito dos tratamentos de calcinação e pirólise de géis secos de aluminosilicato. Materiais e Métodos: As matrizes CuO LAS puras e dopadas foram obtidas pela gelificação de formatos de alumínio e lítio, na presença de tetraetoxisilano e CuO. Os géis obtidos foram secos a 120 ° C e 2,5 h. Metade da quantidade obtida foi submetida a um tratamento de calcinação (480 °C, 5 h) enquanto a outra metade foi submetida a um processo de pirólise (atmosfera de nitrogênio) a 480 °C por 5 h. As amostras obtidas foram caracterizadas por microscopia eletrônica de varredura (MEV), espectroscopia na região do infravermelho (FTIR), potencial zeta e difração de raios X (DRX). Resultados. por meio da análise de MEV, foi confirmado o tamanho micrométrico das partículas, observando-se, a partir dos espectros, algumas bandas proeminentes entre Si-O ou Al-O, além de se considerar que os tratamentos térmicos foram adequados para a liberação de grupos orgânicos de rebasing. Conclusões: A síntese implementada permitiu a obtenção de partículas micrométricas (φp < 25 μm). Os tratamentos térmicos tiveram um efeito significativo sobre a funcionalização superficial das partículas obtidas, e a composição do material e verificou-se que a temperatura utilizada foi adequada para a liberação de reagentes orgânicos, além dos espectros observamos os grupos funcionais de vergalhões que estavam presentes no material.

Influence of drinking water quality on the formation of corrosion scales in lead-bearing drinking water distribution systems.

Lead in drinking water occurs in drinking water distribution systems (DWDS) where lead pipes are used as service lines. Using data gathered from 4 different Canadian cities, we link drinking water quality to composition of corrosion scales obtained on exhumed lead pipes servicing those municipalities. The data presented encompasses a 10-year span and a detailed layer profile analysis of the solids present in lead bearing service lines; where different layers within the corrosion scale formed inside lead pipes are identified and thoroughly characterized. The results obtained clearly show that the corrosion layers in direct contact with drinking water are rich in lead oxides phases and aluminosilicates. In contrast, lead carbonates are the main phases present on corrosion scales in direct contact with the metallic lead pipe. This heterogeneity on phase distribution is correlated to the radial distance from the corrosion scales to the water/solid interphase and water quality servicing those municipalities. Statistical analysis suggests that dissolved Al, Mn, Cu, Ni, and As accumulate on the corrosion scales with preferential accumulation of specific elements heavily dependent on distinct municipality water quality.

Growth performance and meat quality from broiler chickens reared with zeolite and halloysite in feed and straw pellet.

The study's aim was to analyze the effects of different levels of halloysite (H) and zeolite (Z) in feed and pellets on the growth and meat quality in chickens; 500 Ross 308 broilers were assigned to five groups (1 g, control; 2-5 g, experimental). In Groups 2-5, different proportions of Z and H in feed (25:75 ratio; 0.5% to 2%) and pellet in kg/m2 (2, 0.650H; 3, 0.325H and 0.325Z; 4, 0.650Z; 5, 0.160H and 0.490Z) were used. Body weight was higher than 1 in all experimental groups, and carcass weight was higher, except for Group 2. The feed consumption was lower in Groups 3 and 5 than in Group 4. The breast muscle weight was higher in Group 3 than in the control group. In Groups 2, 3, and 5, the water holding capacity in the breast muscles was better than in Group 4 and in the leg muscles in Groups 3 and 4 than in Groups 1 and 5. Most of the tested characteristics indicate a beneficial effect of aluminosilicates in feed and litter on the growth and quality of meat.