Biofiltración de compuestos orgánicos volátiles utilizando diferentes tipos de lecho basados en mezclas de compost de RSU-poda: monitorización mediante diversas técnicas

Tesis descargada en TeseoComposting is one of the most successful biological processes for the treatment of the residues enriched in putrescible materials. The optimization of parameters which have an influence on the stability of the products is necessary in order to maximize recycling and recovery of waste components. The influence of the composting process parameters (aeration, moisture, C/N ratio, and time) on the stability parameters (organic matter, N-losses, chemical oxygen demand, nitrate, biodegradability coefficient) of the compost was studied. The composting experience was carried out using Municipal Solid Waste (MSW) and Legume Trimming Residues (LTR) in 200 L isolated acrylic barrels following a Box-Behnken central composite experimental design. Second-order polynomial models were found for each of the studied compost stability parameter, which accurately described the relationship between the parameters. The differences among the experimental values and those estimated by using the equations never exceeded 10% of the former. Results of the modelling showed that excluding the time, the C/N ratio is the strongest variable influencing almost all the stability parameters studied in this case, with the exception of N-losses which is strongly dependent on moisture. Moreover, an optimized ratio MSW/LTR of 1/1 (w/w), moisture content in the range of 40-55% and moderate to low aeration rate (0.05-0.175 Lair kg-1 min-1) is recommended to maximise degradation and to obtain a stable product during co-composting of MSW and LTR. On the other hand, the concentration of volatile organic compounds (VOCs) during the composting of kitchen waste and pruning residues in a pilot plant, and the abatement of VOCs by different compost biofilters was studied. VOCs removal efficiencies greater than 90% were obtained using composts of municipal solid waste (MSW) or MSW-pruning residue as biofilter material. An electronic nose identified qualitative differences among the biofilter output gases at very low concentrations of VOCs. These differences were related to compost constituents, compost particle size (2-7 or 7-20 mm), and a combination of both factors. The total concentration of VOCs determined by a photoionization analyser and inferred from electronic nose data sets were correlated over an ample range of concentrations of VOCs, showing that these techniques could be specially adapted for the monitoring of these processes. Finally, a biofiltration system was designed using mature composts of municipal solid waste (MSW) or MSW mixed with pruning residues (MSW-P) as packing materials to treat vapours of ¿-pinene (a dominant volatile organic compounds (VOC) emitted during the MSW- P co-composting) and Methyl ethyl ketone (MEK). Monitoring the efficiency of the biofiltration system was carried out using a photoionization analyser, a commercial electronic nose (e-nose) and gas chromatography ¿ mass spectrometry (GC/MS). Results indicated that removal efficiencies for both kinds of biofilters were greater than 90% at different stages of the experiment. The acclimatization periods were 10 and 25 days for the MSW biofilter and MSW-P biofilter, respectively in the experiment with ¿-pinene and 14 days for both biofilters when the MEK was the contaminant present in the air stream to treat. Removal efficiency of the system was strongly dependent upon the moisture content of the packing materials, but the nature of the contaminant (hydrophilic or hydrophobic) plays an important role in the degradation. As moisture content in the biofilters fell to below 66% (dw) for the MSW and 51% (dw) for MSW-P, the removal efficiency decreased to less than 90% when the contaminant was an hydrophobic volatile organic compound (¿-pinene). In the case of MEK, the optimal range of moisture content for the packing materials used in this experiment was between 21.5 and 67.5 % (d.w) in the case of the MSW biofilter and between 25.7 and 91.8 % (d.w) for MSW-P biofilter. E-nose and GC/MS data indicate a complete degradation of the ¿-pinene and MEK by biofiltration, although the e-nose did detect background emissions, characteristic of each type of biofilter. Also, was possible to obtain information about the performance of the biofiltration system in different stages of the experiment. Results suggest that e-nose¿s will become a more powerful tool for monitoring VOC compounds in biofiltration and composting processes in the future

Natural Medicinal Plants

This book, Natural Medicinal Plants is a comprehensive overview of drugs derived from medicinal plants and their use in treating human illnesses such as cancer. Chapters include scientific evidence on flora rich in active ingredients

Estimation of Aroma Determining Compounds of Kangra Valley Tea by Electronic Nose System

Aroma is a major factor for quality evaluation of finished tea.Professional tea taster's distiguish the aroma of finished tea and decide the valuation of tea. Since tea taster's being humans their evaluations could be subjective.Instruments like spectrophotometer, high-performance liquid chromatography(HPLC)and gas liquid chromatography(GLC)measure the chemical/volatile compounds polyphenols,catechins and flavour profile of tea[b]. But these instruments are costly, time consuming, take long time to prepare the sample and also needs expert manpower to operate. Besides Electronic Nose (E-Nose)is also used by different tea factories to supplement the work of a tea taster for predicting the tea taster like score of finished tea. E-Nose can give tea taster like score within one and and half minute and easy of operate. This paper describes the estimation of tea compounds responsible for tea aroma by E-Nose

Biological and Pharmacological Activity of Plant Natural Compounds II

The Special issue "Biological and Pharmacological Activity of Plant Natural Compounds II" is continuing the intriguing research on the use of natural plant products. The second edition follows the aim of the first one

Food science sourcebook

2 v. : ill. ; 26 cm2nd edition.Rev. ed. of: Source book for food scientists. c1978"An AVI book."Pt. 1. Terms and descriptions -- pt. 2. Food composition,properties, and general data

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Factors Associated with Quit Attempts and Smoking Cessation in Brazil: Findings from the International Tobacco Control Brazil Survey

Background:In Brazil, the treatment of tobacco dependence is available at no cost. This study aimed to identify factors associated with attempting to quit and of successful smoking cessation in a population-based sample of Brazilian smokers.Methods:Data came from the first two waves of the International Tobacco Control (ITC) Brazil Survey, conducted in 2009 and 2012/2013 in three cities: Rio de Janeiro, São Paulo, and Porto Alegre. Prospective cohort data were collected from 488 adults (≥18 years) who smoked at Wave 1 who were resurveyed at Wave 2. Crude and adjusted relative risks (RR) for two outcomes (making a quit attempt between Wave 1 and Wave 2 and successfully quitting by Wave 2) were estimated. Multivariable multilevel logistic regression models were used, whereby variables were added to the models in a series of blocks.Results:Nearly two-thirds (65.6%) of smokers attempted to quit between waves, and 23.4% had quit at Wave 2. Intention to quit smoking at Wave 1 was the only variable associated with attempt to quit by Wave 2 (OR=2.85; 95%CI 1.64-4.94; p\u3c 0.001). Smokers of higher socioeconomic status (ORhigh versus low=1.80; 95%CI 1.05-3.10; p=0.03) and lower nicotine dependence (ORlow HSI versus high HSI=1.94; 95%CI 1.10-3.43; p=0.02) were more likely to successfully quit. The presence of another adult smoker at home was negatively related to successful quitting (OR=0.50; 95%CI 0.26-0.94; p= 0.03).Conclusions:These results are generally consistent with prior research and have potential to inform governmental interventions to promote tobacco cessation, particularly among disadvantaged groups