Comparative assessment of the degradation of 2-methylisoborneol and geosmin in freshwater using advanced oxidation processes.

Traditional methodologies of conventional drinking water treatment are unable to remove some chemical compounds, such as those that cause odor and taste in drinking water. The present work aims to evaluate the efficiency of advanced oxidations processes, using UV radiation, O3 and O3 + UV in the degradation of geosmin (GSM) and 2-methylisoborneol (2-MIB) in synthetic samples. The efficiency of the processes was monitored by Gas Chromatography coupled with Mass Spectrometry using solid phase microextration technique. Experiments were carried out for 45 min with samplings every 15 min. The degradation results showed that UV radiation alone was not efficient for the degradation of both compounds. The fasted decay was observed by the combined use of O3 and UV with an ozone concentration of 15.84 mg L-1. Under these conditions, the final concentration of GSM was below the limit of quantification, so that approximately 99% of the initial concentration was degraded, while 2-MIB was degraded by 95%. With the same O3 concentration without the use of UV radiation, 63% and 65.7% of MIB and GSM, respectively, were removed. Higher efficiency of the treatment was observed with a higher O3 concentration which allows a shorter reaction time.

Tobacco waste hydrolysate of stem and root of the tobacco plant for biostimulation in rice and corn seed germination / Hidrolisado de resíduo de caule e raiz da planta tabaco para bioestimulação na germinação de sementes de arroz e milho

ABSTRACT: Stimulation of seed germination may be due to acceleration of germination as well as due to seedling growth-promotion during early development. Plant hydrolysate can be applied as a stimulant. Thus, we aimed to verify the influence of the hydrolysates, obtained by alkaline or acid treatment, from tobacco (Nicotiana tabacum L.) crop residues (root and stem) on the seed germination process. Seed germination was studied with Oryza sativa (rice) and Zea mays (corn). Sixteen germination experiments of 50 seeds each were undertaken, with 4 replicates, soaked with hydrolysates diluted at 20 and 80%, in 2 and 3 mL of hydration volumes for 48 h. Germinated seeds were counted, at which point radicular protrusions were observed. Rootlets and aerial parts were collected, dried and weighed. The hydrolysates presented seedling nutrition potential to the corn, with ~50% more mass compared to the results with water at the same conditions, and the germination acceleration was not significant. For the tested rice seeds, the results were reversed, and the germination acceleration was significant with rates up to 94% after 48 h of incubation. Better results of germination were obtained with hydrolysate from acid treatment, and root or stem tobacco can be used for this purpose.

RESUMO: A estimulação da germinação das sementes pode ser devida à aceleração da germinação, bem como à melhoria do crescimento das mudas durante o desenvolvimento inicial. O hidrolisado de plantas pode ser aplicado como estimulante. Assim, objetivou-se verificar a influência dos hidrolisados, obtidos por tratamento alcalino ou ácido, dos resíduos da cultura do tabaco (Nicotiana tabacum L.) (raiz e caule) no processo de germinação das sementes. A germinação das sementes foi estudada com Oryza sativa (arroz) e Zea mays (milho). Foram realizados dezesseis experimentos de germinação de 50 sementes cada, com 4 repetições, hidratadas em hidrolisados diluídos a 20 e 80%, em 2 e 3 mL de volumes de hidratação por 48 h. As sementes germinadas foram contadas, momento em que foram observadas protrusões radiculares. Radículas e partes aéreas foram coletadas, secas e pesadas. Os hidrolisados apresentaram potencial nutricional de plântulas para o milho, com ~ 50% a mais de massa quando comparados aos resultados com água nas mesmas condições, e a aceleração da germinação não foi significativa. Para as sementes de arroz testadas, os resultados foram contrários e a aceleração da germinação foi significativa com taxas de até 94% após 48 h de incubação. Melhores resultados de germinação foram obtidos com hidrolisado a partir do tratamento ácido, e a raiz ou caule de tabaco pode ser utilizado para esse fim.

Evaluation of Zygosaccharomyces bailii BCV 08 as a co-starter in wine fermentation for the improvement of ethyl esters production.

Zygosaccharomyces bailii BCV 08, a yeast isolated from red wine barrels in Brazil, was evaluated as co-starter in fermentations with Saccharomyces cerevisiae. Z. bailii BCV 08 was preliminarily shown to produce high levels of esters, and the production was optimized in bench and bioreactor scales using grape must. White wine vinifications were conducted with mixed cultures containing different proportions of Z. bailii BCV 08 and an enological strain of S. cerevisiae. In all trials that contained Z. bailii BCV 08, the production of ethyl esters was enhanced in comparison to the vinification control. Our results clearly show the potential of Z. bailii BCV 08 as a mixed starter with S. cerevisiae in order to increase the aromatic complexity of wine.

Fourier transform infrared spectroscopy (FTIR) and multivariate analysis for identification of different vegetable oils used in biodiesel production.

The main objective of this study was to use infrared spectroscopy to identify vegetable oils used as raw material for biodiesel production and apply multivariate analysis to the data. Six different vegetable oil sources--canola, cotton, corn, palm, sunflower and soybeans--were used to produce biodiesel batches. The spectra were acquired by Fourier transform infrared spectroscopy using a universal attenuated total reflectance sensor (FTIR-UATR). For the multivariate analysis principal component analysis (PCA), hierarchical cluster analysis (HCA), interval principal component analysis (iPCA) and soft independent modeling of class analogy (SIMCA) were used. The results indicate that is possible to develop a methodology to identify vegetable oils used as raw material in the production of biodiesel by FTIR-UATR applying multivariate analysis. It was also observed that the iPCA found the best spectral range for separation of biodiesel batches using FTIR-UATR data, and with this result, the SIMCA method classified 100% of the soybean biodiesel samples.