Biofiltration of volatile organic compounds of Brazilian gasoline

Gasoline vapors pollute the atmosphere and can be harmful to human and animal health. Tons of particles of this pollutant are expelled to the atmosphere, generating great economic losses to the industries and serious damage to the environment. Biofiltration is an option of simple technology with low costs that can be used for the gasoline vapor treatment. The present study was carried out in two biofilter systems of laboratorial scale. The biofilter system 1 was operated with a total volume of 2.72 L (four columns) and the biofilter 2 with 2.04 L (three columns) of total volume. Both of them were operated in sequence, with airflow of 450 mL entering each one. Results obtained were as follows for the removal efficiency (RE) of different gasoline vapor concentrations in the air: 1.3 g.m-3 during 35 days, RE of 100%; 3 g.m-3 during 52 days, RE of 90%; 4.5 g.m-3 during 48 days, RE of 70-80% and 8g.m-3 during 28 days, RE of 70%.

Pretreatment strategies for delignification of sugarcane bagasse: a review

The valorization of agro-residues by biological routes is a key technology that contributes to the development of sustainable processes and the generation of value-added products. Sugarcane bagasse is an agro-residue generated by the sugar and alcohol industry in Brazil (186 million tons per year), composed essentially of cellulose (32-44%), hemicellulose (27-32%) and lignin (19-24%). The conversion of sugarcane bagasse into fermentable sugars requires essentially two steps: pretreatment and hydrolysis. The aim of the pretreatment is to separate the lignin and break the structure of lignocellulose, and it is one of the most critical steps in the process of converting biomass to fermentable sugars. The aim of this review is to describe different pretreatment strategies to promote the delignification of the sugarcane bagasse by thermo-chemical and biological processes.

Evaluation of poultry litter traditional composting process

The objective of this work was to study the poultry litter composting and evaluate the physico-chemical and microbiological transformations as a time-function. At the end of composting, an increase of humification matter, a decrease of microbial diversity and the elimination of pathogens were observed. Results showed that poultry litter was liable of composting, without any nutritional complementation or inoculation and the process occurred similarly to other kind of organic residues.

Utilization of the biorreactor of imersion by bubbles at the micropropagation of Ananas comosus L. Merril

The research for new techniques of in vitro cultivation is being object of many studies around the world, in order to optimize and decrease production costs of seedlings with agronomical interest. The main goal of this work was to compare different systems of in vitro cultivations using Ananas comosus L. Merril. So, the in vitro growth of the plantlets was promoted in two different bioreactors: Bioreactor of Immersion by Bubbles (B.I.B.®) and the Reactor of Temporary Immersion (R.I.T.A.®) with immersion cycle every 2 hours for 15 minutes and the traditional system in flasks with 200 mL. All cultivation systems used the MS liquid nutritive solution, supplemented with BAP (1 mgL-1), ANA (0.25 mgL-1), sucrose (30 gL-1) and Tween 20® (0.5 µL). The pH was adjusted to 5.8 and sterilized at 120°C for 15 minutes. The cultures were kept into a growth room during 30 days, with controlled temperature of 25±2°C, under white cold light (46.8 µmol.m-2.s-1), with photoperiod of 16 hours. The experimental design used was randomized, with three treatments, three repetitions and ten plants each stage. Among the evaluated systems, the BIB® presented the best results for the tested variables, mainly the total number of shoots, being 2.3 e 3.1 times superior when compared with the system R.I.T.A.® and the traditional consecutively. So the system of immersion by bubbles turns into an effective equipment to produce seedlings of pineapple in large scale.

A busca por novas técnicas de cultivo in vitro vem sendo amplamente estudadas, visando otimizar e baixar o custo de produção das mudas que tenham interesse agronômico. O objetivo deste trabalho foi comparar diferentes sistemas de cultivo in vitro de Ananas comosus L. Merril. Para tanto, o crescimento in vitro de plântulas foi promovido em sistemas de biorreatores (B.I.B.® e R.I.T.A.®) com ciclo de imersão a cada 2 horas por 15 minutos e o sistema tradicional em frascos de 200 mL. Em todos os sistemas de cultivo, foram utilizadas solução nutritiva líquida MS, suplementado com 1 mg L-1 de BAP, 0,25 mg L-1 de ANA, 30 g L-1 de sacarose e 0,5 µL de Tween® 20, pH ajustado para 5,8 e autoclavagem a 120°C por 15 minutos. As culturas foram mantidas em sala de crescimento durante 30 dias, temperatura controlada de 25±2°C, sob luz branca fria (46,8 µmol.m-2.s-1), com 16 horas de fotoperíodo. O delineamento foi inteiramente casualizado, com três tratamentos, três repetições e dez plantas por estágios. Para os sistemas avaliados, o biorreator de imersão por bolhas apresentou os melhores resultados dentre as variáveis analisadas, com destaque ao número total de brotações, sendo 2,3 e 3,1 vezes superiores quando comparado com o sistema R.I.T.A.® e sistema tradicional respectivamente. Portanto, o sistema de imersão por bolhas torna-se um equipamento eficaz na produção de mudas de abacaxizeiro em larga escala.

Thermoanalytical and starch content evaluation of cassava bagasse as agro-industrial residue

Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were observed two main mass losses for all samples. Results suggest hydrolysis carried out using enzyme is less effective in order to convert total starch content in cassava bagasse. However, using sulfuric acid, fibers are affected by analyses conditions.

As frações nutricionais bem como as propriedades térmicas e outras análises são essenciais para a indústria de alimentos e suas aplicações O bagaço de mandioca é um importante resíduo agroindustrial e seu teor de amido foi avaliado por dois métodos alternativos. A caracterização por análise térmica e microscopia ajudou na compreensão de como a hidrólise digere a fração amilácea do bagaço de mandioca, O ponto de fusão foi de 170ºC, a análise termogravimétrica (TG) mostrou após a perda de umidade do material, duas principais perdas de massa em todas as amostras analisadas. Os resultados sugerem que a hidrólise enzimática é menos eficiente na conversão total de amido no bagaço de mandioca. No entanto, o uso de ácido sulfúrico degradou até mesmo a parcela fibrosa do material, afetando as condições de análise.

A simplified model for A. Niger FS3 growth during phytase formation in solid State fermentation

A simplified model to describe fungal growth during citric pulp fermentation for phytase production was described for the first time. Experimental data for biomass growth were adjusted to classical mathematical growth models (Monod and Logistic). The Monod model predictions showed good agreement with the experimental results for biomass concentration during 96 hours of fermentation. Parameters such as yield of biomass from oxygen (Y X/O), maintenance coefficient (m) and specific growth rate (µ) were compared showing a good correlation between the data and the model. An alternative method for biomass determination in this process was developed since a great correlation was found between biomass growth and enzyme formation.

Um modelo simplificado para descrever o crescimento fúngico durante a fermentação em polpa citric para a produção da fitase foi descrita pela primeira vez. Dados experimentais para a formação de biomassa foram ajustados a modelos clássicos de crescimento microbiano (Monod e Logístico). O modelo Monod previsto mostrou boa correlação aos resultados experimentais para a concentração de biomassa até 96 horas de fermentação. Parâmetros como rendimento de biomassa a partir de oxigênio (Y X/O), coeficiente de manutenção (m) e taxa específica de crescimento (µ) foram comparados mostrando uma boa correlação entre os dados e o modelo. Um método alternativo para a determinação de biomassa neste processo foi desenvolvido a partir de uma excelente correlação encontrado entre o crescimento microbiano e a formação da enzima.