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DEVELOPMENT OF BIOLOGICAL SYSTEM FOR THE AEROBIC REMOVAL OF N2O - Main researchers: Raúl Muñoz, Raquel Lebrero -Researcher: Laura Salamanques Nowadays, N2O emissions represent a significant part of the total of greenhouse gases in the EU, with an annual increase in the atmospheric concentration of 0.3% (Figure 1) N2O is not only one of the main greenhouse gases (its potential for global warming is 298 times bigger than that of CO2), but also one of the main causes of the disappearance of the ozone layer. N2O is mostly emitted through activities of waste treatment (10 million tonnes of CO2-eq), the production of nitric and adipic acid (27 million tonnes of CO2-eq) and the cattle industry (21 million tonnes of CO2-eq). The minimization and reduction of N2O emissions is therefore mandatory due to its high environmental impact and the application of stricter environmental regulations. - http://envtech.uva.es/pdf/P-N2O_Treatment.pdf BIOTECHNOLOGICAL PROCESSES FOR CH4 GREENHOUSE GAS REDUCTION: FROM CELLS TO BIOREACTORS - Main researchers: Raúl Muñoz Torre, Guillermo Quijano - PhD student: Juan Carlos López. - Greenhouse Gas (GHG) emissions constitute nowadays one of the most critical environmental problems, since they are responsible for global warming and climatic change. In this context, methane (CH4) is a gas with a potential of global warming 23 times bigger than CO2's, and it represents a significant part of the total of GHG emissions. Even though technologies for physicochemical reduction have been traditionally used to reduce CH4 emissions, biotechnologies have recently risen as environmentally friendly techniques, with promising reduction techniques and lower operative costs when compared to their physical and chemical counterparts. However, biotechnologies for CH4 reduction are still suffering from lilmitations such as the limitation for mass transfer, the lack of knowledge about CH4 kinetic biodegradation, the selection and characterization of microorganisms with a high affinity for target GHG - http://envtech.uva.es/pdf/P-Biotechnological_CH4.pdf ANOXIC BIOLOGICAL TECHNOLOGY FOR THE TREATMENT OF VOC (volatile organic compounds) EMISSIONS FROM THE PETROCHEMICAL INDUSTRY - Main researchers: Raúl Muñoz, Guillermo Quijano - Researchers: María Salvador and Raúl Marcos - Petrochemical industrial facilities can be identified as an important emission points of VOC (volatile organic compounds) around the planet. Some VOC petrochemical emissions are characterized by their free O2 nature and the risk of explosion when O2 is present (Blach and Wurst, 2010.) The risks of explosion in bulk storage tanks are usually controlled by inerting the headspace with N2 or CO2 in order to avoid the presence of O2 (Yanisko et al., 2011.) In order to completely remove O2 from headspace, there must be periodic purges of the inert headspace charged with VOC. Therefore, facilities in which bulk fuels/dissolvents are stored are the main sources of VOC emission. This O2-free VOC emissions are usually treated through catalytic incineration or just gas extraction. However, it is important to highlight that these technologies may exhibit prohibitive and/or non-environmentally friendly operative costs. Among all the technologies available for VOC reduction, biological methods are the most sustainable and profitable ones. They have the lowest operative costs and environmental impact. (Estrada et al., 2012, López et al., En prensa). However, an O2-free nature and the risks of explosion that O2 presence would limit the use of conventional aerobical biological techniques for the direct treatment of VOC emissions of the petrochemical industry. However, VOC biodegradation can also be achieved in the absence of O2. Several studies showed that VOCs such as benzene, toluene, ethylbenzene, xylene and even methane can be successfully removed under conditions of anoxic denitrification (Phelps y Young, 1999, Shag et al., 2005.) These previous studies were focused on the treatment of pollutants in water phase, in closed systems and in batch mode. They confirmed the viability of using denitrification as a central metabolic process in VOC degradation. In our lab, we have developed an innovative biofiltering technology based on the anoxic biodegradation of VOCs. In contrast to the traditional aerobic biofiltering, anoxic biofiltering does not require the conventional supply of O2 to mineralize VOC. Therefore, VOC contained in free O2 currents can be directly removed, thus avoiding the use of expensive physicochemical technologies and the risk of explosions. On the other hand, since the final gaseous products in denitrification are N2 and CO2, the free VOC gas can be reused after the anoxic system for inertification, which lead to important savings in the general costs of the petrochemical operation. -http://envtech.uva.es/pdf/P-Biological_Anoxic_Technology.pdf SUSTAINABILITY AND ECONOMICAL ANALYSIS OF ODOR REMOVAL TECHNOLOGIES. - Main researcher: Raúl Muñoz Torre - PhD student: Raquel Lebrero Fernández and José M. Estrada Pérez Atmospheric pollution, and most specifically odor pollution has traditionally received less atention than solid or liquid pollution. However, this situation is starting to change as a result of the people complaints for odor gradually increase in residential areas. Some of them have been invaded by possible odor sources, the increase in standards of quality of life and the application of stricter legislations. For this reason, there is a growing need to reduce odor in an economical and sustainable way. However, the selection criteria for odor removal technologies are often extrapolated to the industrial installation of VOC treatments, and thic knowledge cannot be directly applied to odor reduction. - http://envtech.uva.es/pdf/P-Sustainability_Odour_Analysis.pdf HIGH PERFORMANCE BIOLOGICAL PROCESSES FOR ODOR ELABORATION IN SEWAGE TREATMENT PLANTS. - Main researcher: Raúl Muñoz Torre, Raquel Lebrero - PhD student: José M. Estrada Due to the stricter environmental regulations, the residential areas being invaded by sewage treatment plants and the growing expectations of the population about the private water companies’ obligations, the number of complaints regarding public odors has substantially increased during the last decades. More than half of the complaints received by environmental regulatory agencies around the world were about bad smells. In this context, the EDAR’s odor emissions mostly consisting of sulphur compounds (H2S, mercaptans) and volatile organic compounds (VOC) are ranked among the most unpleasant ones. For this reason, minimization and reduction of odor emissions are becoming ones of the biggest challenges for public sewage companies around the world, which are increasingly concerned about their public image. Despite the important technological advances carried out during the last two decades, odor treatment systems are still limited by the high operative costs of physicochemical methods, by the low efficiency of odor reduction when hydrophobe odors are the main authors of the earthy smell when low cost technological solutions are implemented as biofiltering unities. This project's aim is to develop a high performance generation of low cost bioreactors for odor reduction with a reduced footprint (minimal requirements of the reactor’s volume). - http://envtech.uva.es/pdf/P-Odour_Treatment.pdf BIODEGRADATION OF VOCs IN TWO-PHASES - Main researchers: Raúl Muñoz Torre, Guillermo Quijano VOCs are key atmospheric pollutants due to its ozone depletion potential, global warming potential, toxicity and carcinogenicity. VOCs are emitted in chemical and petrochemical industries, printing and textile facilities, paper and cellulose industries, etc. The amount of dissolvents used in these industries produces gas emissions with diverse mixtures of VOCs, hydrophobicity, toxicity and biodegradability. Even though conventional technologies for chemical VOC treatment have been progressively set aside by biological technologies, VOC biological removal performance is often questioned by some specific VOC’s (such as alkanes and terpenes) hydrophobicity, which limits the transfer of pollutants from gaseous to water phase. Besides, biological processes are also challenged by increases in the loading rate of emissions containing moderately soluble toxic VOC, which leads to the microbian community’s inhibition. Because of this, there must be a development of innovative bioreactors which support an easy VOC transfer to microorganisms and that avoid microbian inhibition. - http://envtech.uva.es/pdf/P-VOCs_Biphasic_Treatments.pdf STABILITY OF PSEUDOMONAS PUTIDA CULTURES DURING TOLUENE’S TREATMENT - Main researchers: Guillermo Quijano, Raquel Lebrero and Raúl Muñoz Aromatic hydrocarbons emissions and accidental spills could cause a potential risk for natural ecosystems and human health due to its high mobility, toxicity and, in many cases, carcinogenic efffects (Fig 1). In this context, biological treatment methods constitute a well established, low cost alternative to conventional physicochemical technologies fot the destruction of organic pollutants. Environmental biotechnologies are based on the microorganisms’ natural ability of using this toxic organic pollutants as a source of carbon and energy in soft conditions of temperature and pressure. Biological methods present, however, serious limitations when handling with high concentrations of aromatic hydrocarbons, due to its inherent toxicity and mutagenic character, which finally challenges microbian stability. Aromatic hydrocarbons may cause irreversible damage to cellular membrans (ion loss, metabolites, fat and proteins, unwinding of the pH gradient and electric potential, etc.) followed by cellular lysis and death. Operational problems derived from the microbian instability in toluene related process have been recently reported in literature. For example, Song and Kinney (2005) reported a decrease in the removal of biofilters subjected to high toluene charges, probably due to the deterioration of the degrading toluene community, although the mechanisms responsible for this deterioration were not identified. Similarly, Leddy et al. (1995) reported that the presence of benzoate and benzyl alcohol, which often accumulated intermediaries during the biodegradation of toluene, gave as a result irreversible mutations in the toluene’s degradation pathways. However, there is a lack of systematical studies regarding the influence of mutations mediated by toluene in the overall process performance (this is, removal ability, removal efficiency, CO2 production, etc.) - http://envtech.uva.es/pdf/P-Microbial_Stability.pdf

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