Navegando por Autor "Rodrigo, Manuel Andres"
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Artigo Application of electrokinetic soil flushing to four herbicides: a comparison(Elsevier, 2016-06) Santos, Elisama Vieira dos; Souza, Fernanda L.; Sáez, Cristina; Cañizares, Pablo Canizares; Lanza, Marcos R. V.; Martinez-Huitle, Carmem A.; Rodrigo, Manuel AndresIn this work, four bench-scale plants containing soil spiked with four herbicides (2,4-Dichlorophenoxyacetic acid (2,4-D), oxyfluorfen, chlorsulfuron and atrazine) undergo treatment consisting of an electrokinetic soil flushing (EKSF). Results clearly demonstrate that efficiency of EKSF depends on the chemical characteristic of the pesticide used. The amount of pesticide collected in the anode well is more significant than that collected in the cathode wells, indicating that the electromigration is much more important than drainage by electro-osmotic flux for this application. After 15 d of treatment, the 2,4-D is the pesticide most efficiently removed (95% of removal), while chlorsulfuron is the pesticide more resilient to the treatment. Additionally, volatilization was found to be a process of the major significance in the application of electrokinetic techniques to soil polluted with herbicides and because of that it should always be taken into account in the future design of full-scale processesTese Desenvolvimento e otimização de processos assistidos eletroquimicamente para a produção de dióxido de cloro(Universidade Federal do Rio Grande do Norte, 2022-02-28) Monteiro, Mayra Kerolly Sales; Santos, Elisama Vieira dos; Rodrigo, Manuel Andres; https://orcid.org/0000-0003-2189-5694; http://lattes.cnpq.br/8117747568545202; https://orcid.org/0000-0003-2376-2609; http://lattes.cnpq.br/6615971316985436; Huitle, Carlos Alberto Martinez; http://lattes.cnpq.br/2485073932883264O dióxido de cloro é um dos oxidantes mais interessantes, pois combina uma forte capacidade oxidante com uma baixa formação de subprodutos perigosos como os orgânicos clorados durante sua aplicação. Por esse motivo, é amplamente utilizado na desinfecção de água potável e seu uso na desinfecção de superfícies ou edifícios está atualmente em avaliação. Embora geralmente seja produzido pela interação química do clorito com o hipoclorito / cloro ou ácido clorídrico, uma alternativa interessante para sua produção é a combinação de clorato e peróxido de hidrogênio em meio fortemente ácido. Ambos os compostos são conhecidos por serem eficientemente fabricados com tecnologia eletroquímica, abrindo a possibilidade de um processo eletroquímico completo para a produção deste importante oxidante. Esta tese resume os avanços recentes na produção eletroquímica de matérias-primas, bem como na produção eletroquímica completa de dióxido de cloro, não só dando atenção à literatura científica, mas principalmente às patentes recentes, procurando ver em que nível de disponibilidade tecnológica está. cada uma das tecnologias e quais são os elementos da cadeia de valor necessários para uma implementação completa da tecnologia.Tese Novos desenvolvimentos tecnológicos para a eliminação de poluentes voláteis no tratamento de solos assistidos eletroquimicamente(Universidade Federal do Rio Grande do Norte, 2022-02-25) Henrique, João Miller de Melo; Santos, Elisama Vieira dos; Rodrigo, Manuel Andres; https://orcid.org/0000-0003-2189-5694; http://lattes.cnpq.br/8117747568545202; https://orcid.org/0000-0001-9504-6535; http://lattes.cnpq.br/6134014617882124; Huitle, Carlos Alberto Martinez; http://lattes.cnpq.br/2485073932883264O tratamento de solos poluídos é uma das prioridades na busca por um planeta mais sustentável. A remediação de solos assistida eletroquimicamente tem sido considerada uma boa opção, especialmente quando associada a outros processos na eliminação de contaminantes orgânicos contidos no solo. Entretanto, os processos de base eletroquímica geram uma contaminação secundária por fluidos, especialmente na produção de fluxos gasosos. Nesse cenário, foi proposto neste trabalho a combinação de tecnologias para o tratamento de solos contaminados com compostos organoclorados com foco na produção dos fluxos gasosos. Para os experimentos em escala de bancada, foram combinadas as tecnologias de lavagem eletrocinética de solos (EKSF) com a extração de ar (AS) e, para os experimentos em escala piloto, a remediação eletrocinética (EK) com e sem lavagem de solo associada com a extração de vapor (SVE). Os resultados em escala de bancada mostraram que a tecnologia EKS+AS pode remover mais de 90% de compostos fenólicos contidos em um solo bruto após 14 dias de tratamento, enquanto testes envolvendo a remediação de um solo enriquecido com lindano alcançaram 50% de remoção. Em escala piloto, foram estudadas as associações entre SVE+EK e SVE+EKSF, além do emprego da SVE sozinha, na remediação de uma matriz envelhecida contendo uma mistura de hexaclorociclohexanos (γ-HCH, ε-HCH, α-HCH, δ-HCH) integrada a uma matriz sintética fresca de solo compactada. Os resultados mostraram que 70% de remoção foi alcançada apenas com a SVE. Associar SVE+EK afetou negativamente a remoção dos contaminantes. A perda de conteúdo de água no solo indicou sobre a necessidade de usar EKSF no lugar de EK. No entanto, 90% de remoção foi alcançada empregando as tecnologias integradas EKSF+SVE. Os resultados demonstraram que a combinação de EKSF e SVE pode ser positiva, mas é necessária a aplicação de campos elétricos elevados para promover uma temperatura mais elevada no sistema em escala piloto, o que melhora a volatilização do HCH contido no sistema. O transporte EK é aprimorado com a aplicação de campos elétricos, mas esses processos de transporte são muito mais lentos do que os processos de volatilização, que são os primários neste sistema.Artigo Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes(Elsevier, 2016-04-15) Santos, Elisama Vieira dos; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo Canizares; Rodrigo, Manuel AndresIn this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removalArtigo Reversible electrokinetic adsorption barriers for the removal of atrazine and oxyfluorfen from spiked soils(Elsevier, 2017-01-15) Santos, Elisama Vieira dos; Sáez, Cristina; Cañizares, Pablo Canizares; Martínez-Huitle, Carlos Alberto; Rodrigo, Manuel AndresThis study demonstrates the application of reversible electrokinetic adsorption barrier (REKAB) technology to soils spiked with low-solubility pollutants. A permeable reactive barrier (PRB) of granular activated carbon (GAC) was placed between the anode and cathode of an electrokinetic (EK) soil remediation bench-scale setup with the aim of enhancing the removal of two low-solubility herbicides (atrazine and oxyfluorfen) using a surfactant solution (sodium dodecyl sulfate) as the flushing fluid. This innovative study focused on evaluating the interaction between the EK system and the GAC-PRB, attempting to obtain insights into the primary mechanisms involved. The obtained results highlighted the successful treatment of atrazine and oxyfluorfen in contaminated soils. The results obtained from the tests after 15 days of treatment were compared with those obtained using the more conventional electrokinetic soil flushing (EKSF) technology, and very important differences were observed. Although both technologies are efficient for removing the herbicides from soils, REKAB outperforms EKSF. After the 15-day treatment tests, only approximately 10% of atrazine and oxyfluorfen remained in the soil, and adsorption onto the GAC bed was an important removal mechanism (15–17% of herbicide retained). The evaporation loses in REKAB were lower than those obtained in EKSF (45–50% compared to 60–65%)Artigo Treating soil-washing fluids polluted with oxyfluorfen by sono-electrolysis with diamond anodes(Elsevier, 2017-01) Santos, Elisama Vieira dos; Sáez, Cristina; Cañizares, Pablo Canizares; Martínez-Huitle, Carmem A.; Rodrigo, Manuel AndresThis works is focused on the treatment by sono-electrolysis of the liquid effluents produced during the Surfactant-Aided Soil-Washing (SASW) of soils spiked with herbicide oxyfluorfen. Results show that this combined technology is very efficient and attains the complete mineralization of the waste, regardless of the surfactant/soil radio applied in the SASW process (which is the main parameter of the soil remediation process and leads to very different wastes). Both the surfactant and the herbicide are completely degraded, even when single electrolysis is used; and only two intermediates are detected by HPLC in very low concentrations. Conversely, the efficiency of single sonolysis approach, for the oxidation of pollutant, is very low and just small changes in the herbicides and surfactant concentrations are observed during the tests carried out. Sono-electrolysis with diamond electrodes achieved higher degradation rates than those obtained by single sonolysis and/or single electrolysis with diamond anodes. A key role of sulfate is developed, when it is released after the electrochemical degradation of surfactant. The efficient catalytic effect observed which can be explained by the anodic formation of persulfate and the later, a sono-activation is attained to produce highly efficient sulfate radicals. The effect of irradiating US is more importantly observed in the pesticide than in the surfactant, in agreement with the well-known behavior of these radicals which are known to oxidize more efficiently aromatic compounds than aliphatic speciesArtigo Treatment of ex-situ soil-washing fluids polluted with petroleum by anodic oxidation, photolysis, sonolysis and combined approaches(Elsevier, 2017-02-15) Santos, Elisama Vieira dos; Sáez, Cristina; Cañizares, Pablo Canizares; Silva, Djalma Ribeiro da; Martínez-Huitle, Carlos Alberto; Rodrigo, Manuel AndresIn this research, the treatment of soil spiked with petroleum was studied using a surfactant-aided soil-washing (SASW) process followed by sonolysis (US), photolysis and boron doped diamond electrolysis (BDD-electrolysis) for washing liquid treatment. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing completely the petrochemical compounds by using dosages about 5 g of extracting surfactant (sodium dodecyl sulfate (SDS)) per kg of soil. The main characteristics of the effluents produced in this soil remediation technology as well as the efficiency of the treatment (US, photolysis and BDD-electrolysis) depend on the dosage of SDS. Depollution of the effluents (degradation and mineralization of the organic matter) is related to the reduction in size of micelles formed by SDS and petroleum, and it depends on the treatment used. US and photolysis were inefficient decontamination processes, while BDD-electrolysis favors the complete depletion of micelles. However, the intensification of the efficiency was attained by synergic degradation effects when UV light irradiation and US were coupled with BDD-electrolysis, US/BDD-electrolysis and photo/BDD-electrolysis, respectively. Sulfate (coming from SDS) ions play an important role during the BDD-electrolysis, US/BDD-electrolysis and photo/BDD-electrolysis because persulfate and persulfate radicals are produced (by sulfate activation applying US or photolysis), improving the efficiency of the processesArtigo UV assisted electrochemical technologies for the removal of oxyfluorfen from soil washing wastes(Elsevier, 2017-06-15) Santos, Elisama Vieira dos; Sáez, Cristina; Cañizares, Pablo Canizares; Martínez-Huitle, Carlos Alberto; Rodrigo, Manuel AndresIn this work, it is studied the treatment of soil polluted with oxyfluorfen by Surfactant-Aided Soil-Washing (SASW) and after that, photo-electrolysis was used for the treatment of the soil-washing fluid produced. This liquid waste is characterized by the high concentration of micelles of pesticide and surfactant (sodium dodecyl sulfate, SDS), whose initial size depends on the ratio soil-surfactant used in the soil washing treatment. The waste treatment is studied in terms of the decrease in size of the particles and the depletion of the pollutants. Results clearly demonstrate that photo-electrolysis with diamond electrodes is a very effective treatment technology with results that overcome those obtained by single photolysis and/or single electrolysis with diamond electrodes. The greater improvements attained by combining UV irradiation to the electrolysis were observed in the removal of the pesticide while the removal of the surfactant was little affected. Electrolysis does not only deplete the complete concentration of pesticide but it also shows to be very efficient in the depletion of the surfactant, preventing its potential recycle. The significant concentration of sulfate released during the attack to the surfactant and the effect of the peroxosulfate anions that are formed from the anodic oxidation of that anion, explain the improved performance of the technology in the treatment of washing fluids with higher concentrations of SDS