Hot water treatment effect in the elephant grass ashes calcinated at different temperatures

In recent years, agro-industrial residues have focused attention in the scientific community as a new source ofpozzolans. In Brazil, for example, one of the wastes generated from agro-industrial activities comes fromelephant grass that is cultivated as biomass for energy cogeneration. This study evaluated the effect of hotwater treatment on the crystalline structure of elephant grass ashes calcinated in two different temperature(700 and 900°C). To study the chemical structure and the composition of the ashes the X-ray fluorescence(XRF) and X-ray diffractions (XRD) analyses were carried out. The results achieved in the present workshown that, elephant grass ashes meet the ASTM C-618 standard, for the minimum sum content of the silica(SiO2), aluminum (Al2O3) and iron (Fe2O3) oxides, of 50% to be considered as a pozzolanic material. Thepresence of an amorphous phase has been detected in all XRD patterns. The ashes calcinated at 700°Cshowed lower crystallinity and the treatment with hot water decreased crystallite size, i.e., the material becamemore amorphous. On the other hand, the ashes calcinated at 900°C, less reactive, had a lower content ofK2O. Therefore, the hot water treatment was effective to reduce the potassium content in the ashes. Additionally,it contributed to reduce the crystallite size of silica in the ash calcinated at 700°C, while the effect iscontrary to the ash calcinated at 900°C.Keywords: Mineral addition, biomass, amorphous formation, potassium leaching, crystallite size

Residual ash from biomass of elephant grass (Pennisetum purpureum) as pozzolanic material for partial substitution of Portland cement

O objetivo do presente estudo foi contribuir para a viabilização do uso da cinza de capim elefante em escala laboratorial como uma pozolana ativa em substituição parcial do cimento Portland, através da obtenção e tratamento da cinza e seu estudo em pastas. O trabalho foi desenvolvido em três etapas. Na etapa 1, denominada \"Obtenção da cinza\", foi realizado o estudo das estruturas do capim elefante, que foi separado em folhas, (colmo + bainha) e planta inteira e para análise da cinza de cada parte. Observa-se na cinza que há um teor elevado principalmente, de sílica e potássio, sendo que o teor de sílica é maior na folha, enquanto o de potássio é maior no (colmo + bainha). Na etapa 2, denominada \"Tratamento da cinza\", foram realizados diferentes tratamentos químicos e térmicos no material, com o intuito de diminuir os teores dos íons alcalinos, e, com isso, aumentar a proporção de SiO2 na cinza final. Foram realizados três tratamentos, sendo T1 tratamento no capim elefante antes da queima, com solução ácida, T2 tratamento na cinza de capim elefante com água quente e T3 tratamento também na cinza com solução ácida. Pode-se observar que houve um aumento no teor de sílica nas cinzas após os tratamentos. E por fim, na etapa 3, denominada \"Estudo das pastas\", procurou-se aplicar a cinza com tratamento T3, através da caracterização das pastas. Foram produzidas cinco pastas diferentes, C (somente cimento), CC (cimento - cinza), CS (cimento - sílica ativa), CHC (hidróxido de cálcio - cinza) e CHS (hidróxido de cálcio - sílica ativa). Foram feitos estudos de caracterização dos materiais, como também ensaios para a avaliação das pastas, dentre eles, resistência à compressão e ensaios para análise da hidratação do cimento. A cinza apresentou ser um material reativo. E, para sua aplicação em pasta, pode-se notar que a resistência à compressão da pasta com 20% de cinza não diferiu significativamente da pasta produzida somente com cimento. Pela avaliação de difração de raios X (DRX), observou-se a diminuição dos picos das fases ferrita, aluminato tricálcico, belita e alita, o que é indicativo do processo da reação. Adicionalmente, pela análise de termogravimetria, constatou-se o consumo de portlandita, com o passar do tempo e a formação dos géis de CSH. Com base nos resultados obtidos nas três etapas descritas neste trabalho, pode-se concluir que a substituição parcial do cimento Portland pela cinza de capim elefante como material pozolânico é tecnicamente possível e viável.The aim of this study was to contribute to the use of elephant grass ashes, obtained from laboratory scale, as an active pozzolan in partial replacement of Portland cement, by the production and treatment of these ashes and their evaluation study into pastes. The work was developed in three steps. The step 1, entitled: \"Getting Ash\", was carried out to study the structures of elephant grass, which was separated into leaves, (stem + sheath) and the whole plant, and the ashes of each part were analyzed. It is observed that the ash has high content of silica and potassium, whereas the silica content is higher in the leaf part, while potassium is highest in the (stem + sheath) region. In step 2, entitled \"Treatment of the ash\" there were carried out different thermal and chemical treatments on the material, to reduce the concentration of alkali ions and thereby increase the proportion of SiO2 in the ash. Three treatments were carried out: T1, treatment in the elephant grass before burning, with acid solution; T2, treatment in the elephant grass ash with hot water and; T3, treatment also in the ash with acid solution. It can be observed an increase in the silica content in the ashes after of the treatments. Finally, the step 3 activities, entitled \"Study of pastes\", attempted to apply the ash with T3 treatment, by the characterization of the pastes. Five different pastes were produced, C (cement only), CC (cement - ash), CS (cement - silica fume), CHC (calcium hydroxide - ash) and CHS (calcium hydroxide - silica fume). There were made studies for the characterization of the materials, as well as, the tests for the evaluation of the pastes, such as compressive strength tests and the analyses to measure the hydration of the cement. The ash under consideration showed to be a reactive material. For its application in the paste, it can be noted that the compressive strength of the paste with 20% of the ash did not differ significantly the paste produced with only cement. For the evaluation of X-ray diffraction (XRD), it was observed a decrease of the peaks of the ferrite phases, tricalcium aluminate, alite and belite, which is indicative of the reaction process. In the thermogravimetric analysis, it was observed the consumption of portlandite, in the course of time, and the formation of the CSH. Based on the results obtained in the three steps described in this work, it can be concluded that the partial replacement of Portland cement by elephant grass ash as pozzolanic material is technically possible and viable

Study of functional biofilms as coating in multilayer panels for use in agroindustrial facilities

Este projeto tem como objetivo o estudo do recobrimento superficial de filmes poliméricos à base de látex e breu, com microbicida de prata em painéis multicamadas de bagaço de cana-de-açúcar, reforçados com partículas de bambu (PMBB), visando seu o uso como material isolante térmico em instalação agroindustrial sujeita a ambientes úmidos e com grande carga bacteriana. O projeto foi desenvolvido em quatro etapas. Na etapa 1 (Estudo dos painéis multicamadas), foi realizado o estudo de dois diferentes procedimentos de moldagem, sendo moldagem 1 (PMBB-M1) com prensagem nas camadas e a moldagem 2 (PMBB-M2) sem prensagens nas camadas. Na avaliação física e mecânica o painel PMBB-M2 apresentou melhor desempenho físico e mecânico, por conta da melhor interação entre as camadas, quando comparado ao painel PMBB-M1. A etapa 2 (Estudo do tratamento superficial dos painéis) consistiu na produção e caracterização dos filmes de breu, látex-LT e látex-LS, e na avaliação do recobrimento do painel PMBB e da sua durabilidade expostos às intempéries ambientais (sol, chuva, vento e orvalho). Os filmes apresentaram bom desempenho físico, dificultando a penetração de água no material, contudo, a exposição à radiação e as intempéries climáticas promoveram a degradação dos filmes, apesar disso o látex-LT e o breu apresentaram, até os três meses de envelhecimento natural, melhor desempenho mecânico. A etapa 3 (Estudo da impregnação de nanopartículas de prata (AgNPs) nos filmes) consistiu na preparação e avaliação dos filmes com AgNPs. Por meio da análise microbiológica constatou-se que os filmes de látex-LT e breu apresentaram caráter bacteriostático. Por fim, na etapa 4 (Aplicação dos painéis PMBB em Instalação Suinícola), foi analisado o potencial do painel PMBB-M2 como material isolante térmico, na forma de abrigo para leitão (escamoteador) em uma granja de suínos. Nessa etapa, foi avaliado o microclima gerado no interior dos escamoteadores aquecidos com lâmpada incandescente, por meio da coleta de dados ambientais e análise dos índices de conforte térmico. O painel apresentou bom desempenho, atendendo a faixa de temperatura e umidade de conforto térmico para os leitões na primeira semana de vida. Portanto, pode-se concluir que os filmes de breu e látex-LT no painel PMBB-M2, promoveram uma impermeabilização do material e por apresentarem caráter bacteriostático, evitaram a proliferação de bactérias quando em contato com os filmes, sendo assim, a aplicação deste material como isolante térmico em instalação para suíno apresenta um grande potencial, pois, o recobrimento no material propicia sua aplicação em um ambiente úmido e com grande carga bacteriana.This project aims the study of surface coatings with polymeric films based on latex and rosin, by using a microbicide agent of\' silver in multilayer panels of sugarcane bagasse reinforced with bamboo particles (PMBB) to be used as an insulate material in agroindustrial facilities subject to humid environments with high bacterial load. This project was conducted into four steps. In the step 1 (Study of the multilayer panels), the evaluation of two different molding procedures was conducted, with molding 1 (PMBB-M1) with pre-pressing in the layers and molding 2 (PMBB-M2) without pre-pressing in the layers. Physical and mechanical properties of the PMBB-M2 panel presented better physical and mechanical performance due to the best interaction between the layers compared to the PMBB-M1 panel. In the step 2 (Study of the superficial treatment of panels), it was studied the production and characterization of the films of rosin, latex-LT and latex-LS, as well as the evaluation of the PMBB panel covering, and evaluation of the durability of these panels exposed to weather conditions (sun, rain, wind and dew). The films presented good physical performance, making it difficult to penetrate water in the material, on the other hand, by exposing the materials to radiation and weather conduction it was noticed the degradation of the films, despite the fact that latex-LT and rosin presented better mechanical performance until three months of age. In the step 3 (Study of impregnation of silver nanoparticles (AgNPs) in the films) it was conducted the preparation and evaluation of the films with AgNPs. By means of the microbiology analyses it was stated that the latex-LT and rosin presented bacteriostatic character. In the step 4 (Application of PMBB panels in Poultry facilities) it was evaluated the potential of the PMBB panel as an insulation material in a pig-farm as a piglet shelter. In this step, the microclimate generated inside of the pig shelter heated by incandescent lamps was evaluated through the collection of environmental data and evaluation of the thermal comfort indices. The panel presented good performance, taking into account the temperature and humidity range of thermal comfort for the piglets in the first week of life. Therefore, it can be concluded that the films of rosin and latex-LT in the PMBB panel, promoted a waterproofing of the materials and due to the bacteriostatic character, it was noticed that proliferation of the bacteria when in contact with the films was avoided, thus, the application of this material as thermal insulation in pig installation presents a great potential, due to the coating in the material and propitiates its application in a humid environment and with bacterial load

Interaction between Biofilm Formation, Surface Material and Cleanability Considering Different Materials Used in Pig Facilities—An Overview

Sometimes the contamination in pig facilities can persist even after the washing and disinfection procedure. Some factors could influence this persistence, such as bacteria type, biofilm formation, material type and washing parameters. Therefore, this review summarizes how the type of surface can influence bacteria colonization and how the washing procedure can impact sanitary aspects, considering the different materials used in pig facilities. Studies have shown that biofilm formation on the surface of different materials is a complex system influenced by environmental conditions and the characteristics of each material’s surface and group of bacteria. These parameters, along with the washing parameters, are the main factors having an impact on the removal or persistence of biofilm in pig facilities even after the cleaning and disinfection processes. Some options are available for proper removal of biofilms, such as chemical treatments (i.e., detergent application), the use of hot water (which is indicated for some materials) and a longer washing time

<b>Modular panel with wood and particleboards of sugarcane bagasse for cattle handling facilities

This work aimed at the construction and structural evaluation of modular panel with reforested wood, particleboards of sugarcane bagasse and a bi-component resin based on castor oil, for use in lateral closing for construction of crowding pens and chutes for cattle handling facilities. The quality of the particleboards was evaluated considering the requirements of NBR 14810 (ABNT, 2006) and A208.1 (ANSI, 1999). The structural performance of the modular panel was evaluated by the soft body impact testing. The results indicate that the particleboards have physical and mechanical properties that meet the minimum recommendations of the normative documents for structural use. The modular panel shows structural performance suitable to withstand impact loads equivalent to conditions of use, and can be used in cattle handling facilities

Efeito do tratamento de água quente nas cinzas de capim elefante calcinadas em diferentes temperaturas

[EN]: In recent years, agro-industrial residues have focused attention in the scientific community as a new source of pozzolans. In Brazil, for example, one of the wastes generated from agro-industrial activities comes from elephant grass that is cultivated as biomass for energy cogeneration. This study evaluated the effect of hot water treatment on the crystalline structure of elephant grass ashes calcinated in two different temperature (700 and 900°C). To study the chemical structure and the composition of the ashes the X-ray fluorescence (XRF) and X-ray diffractions (XRD) analyses were carried out. The results achieved in the present work shown that, elephant grass ashes meet the ASTM C-618 standard, for the minimum sum content of the silica (SiO2), aluminum (Al2O3) and iron (Fe2O3) oxides, of 50% to be considered as a pozzolanic material. The presence of an amorphous phase has been detected in all XRD patterns. The ashes calcinated at 700°C showed lower crystallinity and the treatment with hot water decreased crystallite size, i.e., the material became more amorphous. On the other hand, the ashes calcinated at 900°C, less reactive, had a lower content of K2O. Therefore, the hot water treatment was effective to reduce the potassium content in the ashes. Additionally, it contributed to reduce the crystallite size of silica in the ash calcinated at 700°C, while the effect is contrary to the ash calcinated at 900°C.[PT]: Nos últimos anos, os resíduos agroindustriais têm ganhado atenção na comunidade científica, como uma nova fonte de pozolana. No Brasil, por exemplo, um dos resíduos gerados pelas atividades agroindustriais provém do capim-elefante que é cultivado como biomassa para a cogeração de energia. Este estudo avaliou o efeito do tratamento com água quente na estrutura cristalina da cinza de capim elefante calcinada em duas temperaturas diferentes (700 e 900°C). Para estudar a estrutura química e a composição das cinzas foram realizadas as análises de fluorescência de raios-X (FRX) e difração de raios-X (DRX). Os resultados obtidos no presente trabalho mostraram que, as cinzas de capim elefante atendem as especificações da norma ASTM C-618, como, o teor mínimo da soma dos óxidos de silício (SiO2), de alumínio (Al2O3) e de ferro (Fe2O3), de 50%, para ser considerado como um material pozolânico. A presença de uma fase amorfa foi identificada em todos os difratogramas. As cinzas calcinadas a 700°C apresentaram menor cristalinidade e o tratamento com água quente diminuiu o tamanho de cristalito, ou seja, o material tornou-se mais amorfo. Entretanto, as cinzas calcinadas a 900°C, apesar de possuir menor teor de K2O, apresentaram maior cristalinidade, sendo menos reativas. Portanto, o tratamento com água quente foi efetivo para a redução do teor de potássio nas cinzas. Como também, contribuiu para reduzir o tamanho de cristalito da sílica das cinzas calcinadas a 700°C, no entanto, o efeito foi contrário para as cinzas calcinadas a 900°C.The authors are grateful to FAPESP (Grants 2011/16842-5, 2016/07372-9, 2013/23810-8 and 2012/51467-3), to CNPq (Grants 150384/2016-5, 312151/2016-0 and 306386/2013-5) and to the Framework Agreement of Collaboration between IETcc/CSIC (Spain) and FZEA/USP (Brazil) (Grant: 2013040043). Also, to i-LINK Program between CSIC (Grant: i-Link 0675-2013), and FAPESP (Grant 2013/50790-8) for their financial support.Peer reviewe

STRUCTURAL PERFORMANCE OF MODULAR WOOD PANEL OF PLANTED FOREST AND PARTICLEBOARDS BASED ON SUGARCANE BAGASSE

The production and study of alternative material produced with lignocellulosic waste&nbsp; to application in livestock production installation is not common in Brazil, however, is a great sustainable alternative as substitutes of conventional materials, therefore, the present study aimed to evaluate the structural performance of modular panel of homogeneous sugarcane bagasse particleboards and reforestation wood, by numerical and experimental analysis, with application prospect as lateral closure in cattle handling facilities. The evaluation of the modular panel performance was conducted by a numerical simulation by way of finite elements, in laboratory by soft body impact test, in situ, applied to a crowding pen of corral for cattle management. The results indicated good correlation among experimental and theoretical values and the modular panels met satisfactorily the proposed use as a lateral closure for cattle handling facilities

Efeito do intervalo de tempo entre os dias de manejos sobre a reatividade em bovinos de corte

The objective was to evaluate the reactivity of two groups (A and B) of bovine (Guzerá) under different time intervals between the managements. Observations of behaviors stopped (P), walking (C), trotting (T), and escape distance (DF) 3m, 5m and greater than 5 meters, were collected. The results showed differences between groups in the third period of handling (P <0.05), with group A had more animals in DF 3m, a decrease in DF of 5m and an increase in walking behavior in relation to group B, thus suggesting that the reactivity decreases with the interaction process.Objetivou-se avaliar a reatividade de dois grupos (A e B) de bovinos (Guzerá) sujeitos a diferentes intervalos de tempo entre os manejos. Observações dos comportamentos parado (P), caminhando (C) e trotando (T), bem como distância de fuga (DF) de 3m, 5m e maior que 5 metros, foram coletados. Os resultados mostraram diferença entre os grupos no terceiro período de manejo (P<0,05), sendo que o grupo A apresentou mais animais na DF de 3m, uma diminuição na DF de 5m e aumento no comportamento caminhar em relação ao grupo B, sugerindo assim, que a reatividade diminui com o processo de interação