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This work performed co-AD from the vinasse and filter cake (from 1G ethanol production) and deacetylation liquor (from the pretreatment of sugarcane straw for 2G ethanol production) in a semi-Continuous Stirred Tank Reactor (s-CSTR) aiming to provide optimum operational parameters for continuous CH4 production. Using filter cake as co-substrate may allow the reactor to operate throughout the year, as it is available in the sugarcane off-season, unlike vinasse. A comparison was made from the microbial community of the seed sludge and the reactor sludge when CH4 production stabilized. Lactate, butyrate, and propionate fermentation routes were denoted at the start-up of the s-CSTR, characterizing the acidogenic phase: the oxidation-reduction potential (ORP) values ranged from -800 to -100 mV. Once the methanogenesis was initiated, alkalizing addition was no longer needed as its demand by the microorganisms was supplied by the alkali characteristics of the deacetylation liquor. The gradual increase of the applied organic load rates (OLR) allowed stabilization of the methanogenesis from 3.20 gVS L-1 day-1: the highest CH4 yield (230 mLNCH4 g-1VS) and average organic matter removal efficiency (83% ± 13) was achieved at ORL of 4.16 gVS L-1 day-1. The microbial community changed along with the reactor operation, presenting different metabolic routes mainly due to the used lignocellulosic substrates. Bacteria from the syntrophic acetate oxidation (SAO) process coupled to hydrogenotrophic methanogenesis were predominant (~ 90% Methanoculleus) during the CH4 production stability. The overall results are useful as preliminary drivers in terms of visualizing the co-AD process in a sugarcane biorefinery integrated to scale. KEY POINTS: • Integration of 1G2G sugarcane ethanol biorefinery from co-digestion of its residues. • Biogas production from vinasse, filter cake, and deacetylation liquor in a semi-CSTR. • Lignocellulosic substrates affected the biochemical routes and microbial community. • Biomol confirmed the establishment of the thermophilic community from mesophilic sludge.

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Resumen En el presente trabajo se evaluó la degradación fotocatalítica del herbicida glifosato en solución acuosa con un catalizador comercial (TiO2 Degussa P25) y un catalizador sintetizado a partir de TiO2 dopado con manganeso (TiO2-Mn), soportados en anillos de borosilicato de diámetro interno y externo de 6,52 mm y 7,59 mm, respectivamente, y una longitud aproximada de 9,43 mm, mediante el uso de un reactor continuo de lecho empacado. El catalizador fue caracterizado por FTIR, SEM-EDS y AFM, con lo cual se determinaron algunas propiedades físicas y químicas del mismo. Las condiciones de operación del reactor fueron un caudal de alimentación de 4,25 mL min-1 de una solución de glifosato de pH natural de 4,45 y un tiempo de retención de 1 h y 25 min, en el cual se llevaron a cabo ensayos de fotocatálisis heterogénea, fotólisis y adsorción por un tiempo de 150 min. De lo anterior, se obtuvieron los porcentajes de remoción y el orden de la reacción fotocatalítica para el catalizador soportado en los anillos. A partir de los estudios de degradación realizados, con el TiO2-Mn soportado en los anillos, se logró un porcentaje máximo de degradación de 39.19%, mientras que, con el catalizador comercial TiO2 Degussa P25, se alcanzó un 28.6% de remoción. El modelo de reacción que sigue la degradación del glifosato es de difusión intrapartícula, debido a los procesos difusivos en los que la molécula de glifosato es adsorbida en los poros del catalizador para luego ser degradada.

Abstract In this work, the photocatalytic degradation of the herbicide glyphosate in aqueous solution was evaluated. Assays were performed on a commercial catalyst (TiO2 Degussa P25) and a catalyst synthesized from TiO2 doped with manganese (TiO2-Mn) supported on borosilicate rings, with an internal and external diameter of 6.52 mm and 7.59 mm respectively, and an approximate length of 9.43 mm, using a continuous packed bed reactor. The synthesized catalyst was characterized with techniques as FTIR, SEM-EDS, and AFM, which allowed to evaluating its chemical and physical properties. The reactor operating conditions were a feed flow rate of 4.25 mL min-1 of a pH 4.45 glyphosate solution and retention time of 1 h and 25 min. In such experiments, heterogeneous photocatalysis, photolysis, and adsorption test were carried out for 150 min, obtaining results of degradation percentages and the order of photocatalytic reaction for the catalyst supported in the rings and the powder in suspension. From the removal studies, a maximum degradation percentage of 39.19% was reached with TiO2-Mn supported in the rings. In contrast, the commercial catalyst TiO2 Degussa P25 had a 28.6% of removal. The glyphosate degradation follows an intraparticle diffusion model due to a diffusive process, where the glyphosate molecule is adsorbed in the catalyst pores and then degraded.

Resumo Neste trabalho, a degradação fotocatalítica de glifosato em solução aquosa foi avaliada com um catalisador comercial (TiO2 Degussa P25) e sintetizado a partir de TiO2 dopado com manganês (Mn-TiO2) com suporte em anéis de borosilicato de diâmetro interno e externo de catalisador 6,52 mm e 7,59 mm, respectivamente e um comprimento de aproximadamente 9,43 mm, usando um leito empacotado reator contínuo. O catalisador sintetizado foi caracterizado com FTIR, SEM-EDS and AFM, o que permitiu a sua morfologia e composição. As condições de operação do reactor foi alimentada à velocidade de 4,25 mL min-1 de uma solução de pH natural de 4,45 glifosato e um tempo de retenção de 1 hora e 25 minutos; em que foram realizados ensaios de fotocatálise heterogénea, fotólise, tempo de adsorção de 150 minutos, obtendo-se como percentagens resultados de remoção e com a reação fotocatalítica para o catalisador suportado em anéis. A partir dos estudos, foi obtido uma taxa máxima de degradação com TiO2-Mn suportado em anéis de 39,19% em comparação com o catalisador comercial de TiO2 Degussa P25 com os quais obtiveram porcentagens de degradação de 28,6%. A degradação do glifosato segue um modelo de difusão intrapartícula devido ao processo difusivo em que a molécula de glifosato é adsorvida no catalisador poros logo a ser degradada.

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In the present study, the synthesis of an organic group-modified alumina by the sol-gel method is proposed. This material has shown to have an enhanced catalytic performance with grafted organic groups and showed an improved stability. The prepared material has shown to have several O - H groups and an enhanced surface acidity. The alumina acidity was improved by incorporating thiol groups by grafting method, which promotes the tautomerization of fructose to its furanose form. Furthermore, the grafting of sulfonic groups catalyzes its dehydration. The modified alumina was thermally treated up to 200 °C to improve the functional groups stability. After, this modified material was packed into a continuous reactor system, designed and built by this group, to obtain 5-hydroxymethylfurfural (5-HMF) from fructose dissolved in a single-phase solution of tetrahydrofuran (THF) and H2O (4:1 w/w). The catalytic activity of this material was evaluated by the reaction of fructose dehydration at different reaction temperatures (60, 70, 80 and 90 °C). Fructose conversion and selectivity toward 5-HMF were determined by high performance liquid chromatography (HPLC), obtaining 95% and 73% respectively for the highest temperature. The catalyst showed an efficient stability after 24 hours in continuous flow at 70 °C. The loss of sulfur content was 15%, but the fructose conversion yield and the selectivity to 5-HMF after 24 hours of continuous reaction did not undergo significant changes (less than 5%). The nuclear magnetic resonance (NMR) tests confirmed the presence of the thiol and sulfonic groups before and after 24 hours of reaction, as well as the conservation of the same structure, demonstrating the efficient catalytic performance of the material. The catalysts were characterized by nitrogen adsorption/desorption, X-ray diffraction and infrared (IR) spectroscopy. Also, before and after use by utilizing elemental analysis and   1 H - 13 C cross-polarization magic-angle spinning (CPMAS) and dynamic-nuclear polarization (DNP)-enhanced   1 H - 13 C and   1 H - 29 Si CPMAS as well as directly excited   29 Si magic-angle spinning (MAS) NMR methods in solid-state.

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Lipases are being extensively researched for the production of biodiesel as a "silver bullet" in order to avoid the drawbacks of the traditional alkaline transesterification. In this review, we analyzed the main factors involved in the enzymatic synthesis of biodiesel, focusing in the choice of the immobilization protocol, and the parameters involved in the choice and configuration of the reactors. An extensive discussion is presented about the advantages and disadvantages of each type of reactor and their mode of operation. The current scenario of the market for enzymatic biodiesel and some future prospects and necessary developments are also briefly presented.

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