Unidade de Investigação – LSRE-LCM – Laboratório de Processos de Separação e Reação – Laboratório de Catálise e Materiais – Polo IPLeiria
URI permanente desta comunidade:
O polo do LSRE-LCM – Laboratório de Processos de Separação e Reação – Laboratório de Catálise e Materiais do Politécnico de Leiria foi criado em 2011 e atualmente integra o maior Laboratório Associado Português em Engenharia Química, ALiCE, com uma intervenção muito relevante nas áreas de Engenharia do Ambiente e da Bioengenharia.
Navegar
Percorrer Unidade de Investigação – LSRE-LCM – Laboratório de Processos de Separação e Reação – Laboratório de Catálise e Materiais – Polo IPLeiria por Domínios Científicos e Tecnológicos (FOS) "Ciências Naturais::Ciências da Computação e da Informação"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- A Combined Vermifiltration-Hydroponic System for Swine Wastewater TreatmentPublication . Ispolnov, Kirill; Aires, Luis M. I.; Lourenço, Nídia D.; Vieira, Judite S.Intensive swine farming causes strong local environmental impacts by generating effluents rich in solids, organic matter, nitrogen, phosphorus, and pathogenic bacteria. Insufficient treatment of hog farm effluents has been reported for common technologies, and vermifiltration is considered a promising treatment alternative that, however, requires additional processes to remove nitrate and phosphorus. This work aimed to study the use of vermifiltration with a downstream hydroponic culture to treat hog farm effluents. A treatment system comprising a vermifilter and a downstream deep-water culture hydroponic unit was built. The treated effluent was reused to dilute raw wastewater. Electrical conductivity, pH, and changes in BOD5, ammonia, nitrite, nitrate, phosphorus, and coliform bacteria were assessed. Plants were monitored throughout the experiment. Electrical conductivity increased due to vermifiltration; pH stayed within a neutral to mild alkaline range. Vermifiltration removed 83% of BOD5, 99% of ammonia and nitrite, and increased nitrate by 11%. Hydroponic treatment removed BOD5 (63%), ammonia (100%), nitrite (66%), nitrate (27%), and phosphorus (47% total and 44% dissolved) from vermifiltered water. Coliforms were reduced by vermifiltration but recovered in the hydroponic unit. Plants showed the ability to grow on vermi-filtered wastewater, although requiring nutrient supplementation. Vermifiltration combined with hydroponics is a promising treatment for swine wastewater, although optimization will be needed for a sustainable real-scale implementation.
- Degradation of Oxytetracycline in Aqueous Solutions: Application of Homogeneous and Heterogeneous Advanced Oxidative ProcessesPublication . Giler-Molina, José Miguel; Zambrano-Intriago, Luis Angel; Quiroz-Fernández, Luis Santiago; Napoleão, Daniella Carla; Vieira, Judite dos Santos; Oliveira, Nelson Simões; Rodríguez-Díaz, Joan ManuelOxytetracycline is one of the antibiotics most frequently used in the Shrimp Industry during the control of bacterial diseases. These emerging pollutants, which appear in low concentrations, are persistent and alternative treatments and are required for their elimination. The degradation of oxytetracycline was evaluated in an aqueous solution by applying homogeneous (UV/H2O2 and photo-Fenton) and heterogeneous (UV/TiO2 /H2O2) advanced oxidative processes (AOPs). The studies were carried out using a bench reactor with short-wave ultraviolet lamps (UV-C). We quantified the extent to which the degradation of the drug had been efficient by employing highly efficient liquid chromatography (HPLC) and a PDA detector with a wavelength of 354 nm and a C18 column. The best results were obtained when applying the UV/H2O2 treatment, which attained a degradation of 97% under the initial conditions of a dose of 8 µL of H2O2 and 120 min of radiation. The pseudo-first order kinetic model proposed by Chan and Chu showed that the experimental results had an adequate fit, with values greater than R2 ≥ 0.95. Toxicity tests were applied to verify the effect of AOPs employed, when the drug was present in low concentrations. The test results demonstrated a decrease in the root growth of the species Lactuca sativa and Daucus carota.
- Molecular Dissection of Escherichia coli CpdB: Roles of the N Domain in Catalysis and Phosphate Inhibition, and of the C Domain in Substrate Specificity and Adenosine InhibitionPublication . López-Villamizar, Iralis; Cabezas, Alicia; Pinto, Rosa María; Canales, José; Ribeiro, João Meireles; Rodrigues, Joaquim Rui; Costas, María Jesús; Cameselle, José CarlosCpdB is a 3′-nucleotidase/2′ 3′-cyclic nucleotide phosphodiesterase, active also with rea-sonable efficiency on cyclic dinucleotides like c-di-AMP (3′,5′-cyclic diadenosine monophosphate) and c-di-GMP (3′,5′-cyclic diadenosine monophosphate). These are regulators of bacterial physi-ology, but are also pathogen-associated molecular patterns recognized by STING to induce IFN-β response in infected hosts. The cpdB gene of Gram-negative and its homologs of gram-positive bacteria are virulence factors. Their protein products are extracytoplasmic enzymes (either periplas-mic or cell–wall anchored) and can hydrolyze extracellular cyclic dinucleotides, thus reducing the innate immune responses of infected hosts. This makes CpdB(-like) enzymes potential targets for novel therapeutic strategies in infectious diseases, bringing about the necessity to gain insight into the molecular bases of their catalytic behavior. We have dissected the two-domain structure of Escherichia coli CpdB to study the role of its N-terminal and C-terminal domains (CpdB_Ndom and CpdB_Cdom). The specificity, kinetics and inhibitor sensitivity of point mutants of CpdB, and truncated proteins CpdB_Ndom and CpdB_Cdom were investigated. CpdB_Ndom contains the catalytic site, is inhibited by phosphate but not by adenosine, while CpdB_Cdom is inactive but contains a substrate-binding site that determines substrate specificity and adenosine inhibition of CpdB. Among CpdB substrates, 3′-AMP, cyclic dinucleotides and linear dinucleotides are strongly dependent on the CpdB_Cdom binding site for activity, as the isolated CpdB_Ndom showed much-diminished activity on them. In contrast, 2′,3′-cyclic mononucleotides and bis-4-nitrophenylphosphate were actively hydrolyzed by CpdB_Ndom, indicating that they are rather independent of the CpdB_Cdom binding site.