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Understanding specificities of biohydrogen (bioH2)-producing systems is a key factor to enable efficient energetic exploitation of organic substrates in dark fermentation systems. The use of fixed-film reactors has been pointed as a determining approach to enhance bioH2 evolution due to maintaining high cell densities within reactors. However, limiting substrate availability by excess cell accumulation has been associated with low hydrogenogenic activity levels due to stimulating bioH2-consuming or non-producing pathways. A compartmentalized assessment was used to discover the dynamics of substrate conversion, cell retention patterns and the microbial characterization in different zones of a thermophilic (55 °C) molasses-fed fixed-film reactor under an organic loading rate of 20.0 kg-COD m−3 d−1. Results indicated that microbial populations (e.g. Thermoanaerobacterium genus) in the basal portion of the reactor governed bioH2 production by acetic- and butyric-type fermentation from sugars so that localized substrate availability (3.71 ± 1.13 g-COD g−1VSS d−1) reached favorable levels for bioH2-producing populations. Lactate production by the Janthinobacterium genus occurred only as a secondary metabolic pathway in the bed-region, in which complementary bioH2 production by the co-fermentation of acetate and lactate (also by Thermoanaerobacterium genus) was identified. The obtained results provide insights to manage the operation, as well as the design of acidogenic systems, indicating where and why bioH2-producing populations prevail in fixed-film reactors.

Using pure sugars for fermentative biohydrogen (bioH2) production is known as an economically impeditive approach due to the high costs of raw materials, which leads to the frequent exploitation of residual streams. However, the potentials of using biodigestion as a core processing step in sugarcane biorefineries opens up a wide range of biotechnological possibilities, in which sugar-rich materials may be fermented without adding acquisition costs. This study aimed to finalize the full optimization of the continuous long-term (630 d) thermophilic (55 °C) bioH2 production from molasses, defining adequate hydraulic retention time (HRT) levels. Details of temporal and spatial metabolite distribution profiles coupled to the characterization of microbial communities provided the most complete picture of molasses acidogenesis to date. BioH2 evolution (8.5 NL-H2 L−1 d−1) in full optimized conditions, i.e., HRT ≈ 10.0 h, organic loading rate (OLR) ≈ 86.0 kg-CODt m−3 d−1 and pH ≈ 5.38, exceeded the individual application of optimal OLR (4.5 NL-H2 L−1 d−1) and pH (2.4 NL-H2 L−1 d−1) by almost 200% and 350%, respectively. Biomass washout naturally controlled substrate availability (6.21 ± 2.1 g-COD g−1VSS d−1 for over 300 d), preventing performance losses in the long-term. BioH2 derived from acetic- and butyric-type fermentations was observed in the basal portion of the reactor, whilst butyrate and bioH2 from reverse β-oxidation using lactate prevailed in the bed region. The Thermoanaerobacterium genus was the main group involved in such pathways, and the contribution of the Caproiciproducens genus in caproate production was also revealed. These findings provide consistent directions to scale-up acidogenic systems towards an effective exploitation of full-scale bioH2 production.

Direct hydrogenation of carbon dioxide (CO2) to formic acid is unfavorable thermodynamically, which makes its production limited. In this study, a thermodynamic analysis of CO2 hydrogenation to binary product systems of methanol and formic acid promoted by ionic liquid (IL) (1-ethyl-2,3-dimethylimidazolium nitrite, ([Edmim][NO2]) is presented. The analysis is conducted in Aspen Plus using the Gibbs energy minimization approach combined with a vapor–liquid equilibrium (VLE) for the solvation of CO2 in IL. It is demonstrated that solvating CO2 in ILs is an attractive alternative to overcome the thermodynamic difficulty associated with the product yield, especially formic acid. The [Edmim][NO2] promoted system is very effective for the simultaneous production of formic acid and methanol at 25 °C and 17 bar with a yield of 35% formic acid and 30% methanol at a CO2/H2/IL ratio of 1/2/2. The results show a marked improvement in the yield of formic acid to other previously conducted studies on formic acid production.

Poly-β-hydroxybutyrate (PHB) is a biodegradable biopolymer that may replace fossil-based plastics reducing its negative environmental impact. One highly sustainable strategy to produce these biopolymers is the exploitation of photosynthetic microorganisms that use sunlight and CO2 to produce biomass and subsequently, PHB. Exploring environmental biological diversity is a powerful tool to find resilient microorganisms potentially exploitable to produce bioproducts. In this work, a cyanobacterium (Synechocystis sp.) isolated from a contaminated area close to an important industrial complex was shown to produce PHB under different culture conditions. Carbon, nutrients supply and light intensity impact on biomass and PHB productivity were assessed, showing that the highest yield of PHB achieved was 241 mg L−1 (31%dcw) under high light intensity. Remarkably this condition not only stimulated PHB accumulation by 70% compared to other conditions tested but also high cellular duplication rate, maximizing the potential of this strain for PHB production.

The Cubic Plus Association (CPA) equation of state and the Soave–Redlich–Kwong (SRK) equation of state coupled to Mathias–Copeman and volume correction parameters were used to correlate the vapor pressures and densities of pure polar aprotic solvents (PAS). It is shown that the CPA model (with 2B scheme) performed better than CPA (with inert scheme), SRK and its modifications in all cases for vapor pressure and densities. The performance of two mixing rules, namely the van der Waals one–fluid (vdW1f) and the Huron–Vidal (HV) mixing rules, is evaluated for these models on correlating the bubble–point pressures of CO2 + PAS mixtures. The CPA–HV model performs best at several temperatures, with the global average absolute deviations equal to 7.2 % for CPA–HV, 8.1 % for CPA–vdW1f and 8.7 % for SRK–HV. No improvements were found in the performance of the CPA–vdW1f when the solvation between CO2 and PAS was accounted for regression of bubble–point pressures.

Energetic exploitation of sugarcane-derived byproducts via anaerobic digestion (AD) has recently been highlighted as an alternative to the conventional ethanol-producing approach. In this context, the thermophilic (55 °C) methane production from fermented molasses was assessed in the long-term (>200 d) continuous operation of two anaerobic structured-bed reactors. Two types of alkalinization strategies, namely, NaHCO3 dosing (RM1) and NaOH dosing coupled to effluent recirculation (RM2) were compared, as well as different levels of organic loading rate (OLR) and hydraulic retention time (HRT) were applied to reach limiting operating conditions. Both alkalinization strategies provided an equivalent buffer control up to an OLR of 7.5 kg-CODt m−3 d−1, from which unwanted accumulation of organic acids was observed in RM2. NaHCO3 dosing enabled doubling the OLR (15.0 kg-CODt m−3 d−1) without performance deterioration, i.e., organic matter removal > 80.0% and maximum methane yield values. A detailed assessment of the food-to-microorganism ratio demonstrated the maintenance of stable operating conditions at excess substrate availability (>3.0 g-CODt g−1VSS d−1) in the feeding chamber (FDC) of the reactors, in which substrate conversion exceeded 70.0%. Organic overloads occurred only when biomass retention reached a saturation level in the FDC, hampering the uptake of volatile organic acids, regardless of the operating condition. In any case, the wide range of operating conditions (OLR = 2.5–15.0 kg-CODt m−3 d−1 and HRT = 24.0–36.0 h) associated with maximized methane production characterized a highly flexible process, which enables varied design arrangements in full-scale AD plants.

The use of methane as the energy vector in our current energy matrix has challenged scientists to solve problems, which are now related to the exploration of oil wells but tomorrow will be the foundation for a carbon-neutral industry. Subsea exploration challenges engineers to find new solutions to separate CO2 from CH4 at the extremely high pressure of ca. 400 bar, to which all mature separation technologies are unsuitable. In this review, we highlight possible ways to employ ionic liquid (IL) as a highly selective absorbent to CO2 for extremely high pressure. Besides revising the high-pressure physical-chemical properties of ILs, the IL designing principles, and finally, the current employment of IL for preparing membranes, we prospect possible solutions for the sluggish, disfavored IL-regeneration at high pressure. We prospect—CO2 electro-reduction reaction (CO2RR) as a promising disruption for separation processes, being CO2RR-based technologies viable not only for IL-regeneration after the IL-based CO2 capture but also for CO2 conversion into valuable fuels/chemicals. As a prelude to CO2RR-based technologies, this review highlights key aspects concerning the use of IL as the electrolyte in an electrochemical cell performing CO2RR.

Metabolomic and secretomic analyses of Aspergillus niger IOC 4687 indicated the features of resistance of this strain to copper stress. To investigate the metabolites produced under oxidative stress conditions, gas chromatography–mass spectrometry analysis was performed. The secretome principal component analysis results showed that mannitol could be the main metabolite responsible for conferring resistance to the fungus, and gluconic acid is the possible cause of copper desorption because of its chelating ability. The meta-analysis of the metabolome of A. niger IOC 4687 indicated that a low concentration of sorbitol and ribonolactone during growth may be an indicator of oxidative stress.

2030-12 Creosote is a multicomponent oil classified as a dense non-aqueous phase liquid (DNAPL) produced from coal tar distillation. The concept of phase distribution is critical in decision-making to remediate contaminated sites. The creosote mass transfer between sorbed, aqueous, vapor, and DNAPL phases is controlled by physicochemical characteristics, geology of the site, and environment conditions. This study evaluated phase distribution of the main polycyclic aromatic hydrocarbons (PAHs) of creosote in a sandy soil with low organic matter content. The creosote was collected from a contaminated site in São Paulo, Brazil, and was characterized by gas chromatography–mass spectrometry (GC-MS). Clean soil was collected upgradient from the same area. Initially, the soil was artificially contaminated with creosote. After, the contaminated soil was put in contact with clean water in sealed vials for 72 h. Samples of the soil, vapor, and liquid phases were collected and analyzed by GC-MS. In total, 50 compounds were identified in the creosote, and 9 PAHs were selected to be studied, which represented around 30% of total creosote mass. The major contaminant concentration was detected in the sorbed phase. For instance, naphthalene mass was distributed in sorbed (33.0%), DNAPL (1.5%), aqueous (3.4%), and vapor (0.2%) phases. The results provided an understanding of the contaminant species partitioning that occurs in a real contaminated site

Single-atom zero-valent copper was biosynthesized by a copper-resistant bacterium isolated from a copper mine in Brazil., The chemical synthesis of monoatomic metallic copper is unfavorable and requires inert or reductive conditions and the use of toxic reagents. Here, we report the environmental extraction and conversion of CuSO4 ions into single-atom zero-valent copper (Cu0) by a copper-resistant bacterium isolated from a copper mine in Brazil. Furthermore, the biosynthetic mechanism of Cu0 production is proposed via proteomics analysis. This microbial conversion is carried out naturally under aerobic conditions eliminating toxic solvents. One of the most advanced commercially available transmission electron microscopy systems on the market (NeoArm) was used to demonstrate the abundant intracellular synthesis of single-atom zero-valent copper by this bacterium. This finding shows that microbes in acid mine drainages can naturally extract metal ions, such as copper, and transform them into a valuable commodity.

Made available in DSpace on 2021-06-25T10:16:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 This study aimed at investigating the photochemical behavior of sulfa drugs containing five and six-membered heterocyclic substituents (sulfamethoxazole (SMX) and sulfadiazine (SDZ), respectively), in an aqueous medium. Despite their importance, studies devoted to the use of photochemical models to predict the environmental phototransformation of pollutants in surface waters, by combining laboratory results and natural aquatic systems parameters, are still scarce in the scientific literature. In this work, the second-order reaction rate constants of SDZ and SMX with hydroxyl radicals (●OH), singlet oxygen (1O2), and triplet excited states of chromophoric dissolved organic matter (3CDOM*) were experimentally determined at pH 7, using the competition kinetics approach. The results show that ●OH and 3CDOM* are the key species involved in sulfonamide degradation, with anionic SMX, most prevalent at pH 6–9, being degraded much slower than the anionic form of SDZ. Moreover, SDZ and SMX photodegradation in natural water samples (spring-fed natural pond, public supply reservoir, and sea water) was significantly enhanced relative to depletion in pure water. Finally, from mathematical simulations of the sunlight-driven sulfonamide degradation, half-life times were predicted for these drugs varying from less than 2 to about 90 days, depending on the water depth, concentration of key species (DOC, HCO3−, NO2−, CO32−) in natural aqueous systems, as well as on the particular heterocyclic substituent. Research Group in Advanced Oxidation Processes (AdOx) Department of Chemical Engineering University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, 380 Chemical Systems Engineering Center Department of Chemical Engineering University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, 380 Energy Engineering Department São Paulo State University (UNESP), Av. Dos Barrageiros, 1881 Energy Engineering Department São Paulo State University (UNESP), Av. Dos Barrageiros, 1881

In Brazil, bioelectricity generation from sugarcane bagasse and black liquor is regarded as a sustainable electricity supply option. However, questions regarding land use, investment decisions, and demand for paper, ethanol and sugar make its future role uncertain. The aim of this paper is to present a novel modelling framework based on a soft-link between a multi-sectoral Brazilian integrated assessment model (MUSE-Brazil) and an electricity portfolio optimisation model (EPOM). The proposed framework is capable of dynamically simulating sectoral electricity demand, regional bioenergy production under land use constraints and optimal power sector technological shares in each of the electricity subsystems. Considering Brazil under a 2 °C carbon budget, two scenarios based on economic attractiveness of producing second-generation ethanol have been investigated. Under the scenario where second-generation ethanol is not produced, outputs indicate that by 2050, Brazil would increase sugarcane and wood production by 68% and 49% respectively without causing direct or indirect deforestation. Agriculture intensification is evidenced as an alternative for reducing land use disruptions. Bioelectricity share is projected to remain around 9–10%. However, if second generation ethanol becomes cost-effective, thus limiting bagasse availability, the share of bioelectricity production would decrease to approximately 7.7%, with natural gas-fired plants playing a stronger role in the future power system expansion, causing an increase on electricity sector emissions.

This work evaluates the copper biosorption capacity (Cu2+) by the biomass of a bacterium strain identified as Rhodococcus erythropolis isolated from copper mining environmental samples. The copper uptake was analyzed under different influences of pH, biomass concentration, and metal concentration. The total copper uptake was measured using ICP-OES and the metal adsorption capacity calculated by construction of Langmuir and Freundlich isotherm models. R. erythropolis biomass is a potential material to treat and to remove copper from low concentration of aqueous contaminated effluents reaching a total absorption of 68.03 mg of Cu2+ per gram of biomass according to the Langmuir model at pH = 6, the optimal pH for maximum copper uptake. Our results showed a unique absorption rate when compared to other bacteria belonging to the Rhodococcus genus or even when compared to other bacteria genera able to adsorb metal from aqueous environments. Keywords: Metal biosorption, Bioprocess, Hydrometallurgy, Biomass, Rhodococcus

Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO4], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO4] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.

In general, the oil industry has been searching for ways to alleviate the abundant disposal of oilfield produced water, which contains dissolved hard-removal and highly toxic organic compounds. Advanced oxidative processes (AOPs) have revealed to be effective in the degradation of organic compounds, because they generate hydroxyl radicals with high oxidizing potential which are capable of degrading these compounds. The present study has demonstrated the degradation efficiency of effluents containing organic compounds although the photo-Fenton process using a tubular photochemical reactor under different energy sources. This reactor allowed the use and evaluation of two ultraviolet irradiation sources, the sun and black light lamps, besides other relevant variables to the process, such as reagents concentration and the irradiated area, using a model effluent containing phenol. A sample of oilfield produced water was photochemically degraded through the optimum experimental conditions found for the phenol degradation. Solar irradiation was more efficient than lamplight, and it corresponds an important factor for the reduction of operating costs of this process. The solar reaction system applied to the oilfield produced water showed a removal of organic components up to 76%

The aim of this work was to correlate metabolic changes with copper ions (Cu+2) bioremediation by microalgae C. vulgaris 097 CCMA-UFSCar at low Cu+2 content. The metabolic effects include proteome changes related to fatty acid biosynthesis (value-added product) and carbon fixation (climate change mitigation). Cu+2, even at low concentration, showed a significant negative impact on C. vulgaris growth. The microalgal bioremediation reached 100, 74, 38 and 26% for Cu+2 content at 0.1; 0.3; 0.6 and 0.9 mg L−1, respectively. Regarding proteomics, the numbers of proteins reduced (≈37%) from 581 proteins (control) to 369 proteins (0.9 mg of Cu+2 L−1) compared to control. The microalgal CO2 fixation is strictly related to the Calvin cycle, particularly phase 1, in which ribulose bisphosphate carboxylase large chain (RuBisCO) produces two phosphoglycerate molecules from CO2 and ribulose 1,5-bisphosphate. Then, phosphoglycerate can be metabolically reduced into glucose. When compared to control, the RuBisCO was underexpressed (≈50%). Similar changes in proteomic profiling of metabolism-related to fatty acid biosynthesis was observed. Nevertheless, no protein was found for the cultivation at 0.9 mg of Cu+2 L−1. Thus, the analysis of C. vulgaris proteomic data indicated that even at low concentration, Cu+2 lead to drastic metabolic changes.

Dark fermentation (DF) systems usually exploit bioH2 production aiming to improve the energetic potential (EP) of anaerobic digestion (AD) schemes. In the case of sulfate-rich substrates, the versatility of fermentative consortia may favor the establishment of sulfidogenic conditions, minimizing/eliminating the competition between sulfate-reducing bacteria (SRB) and methanogens in the sequential stage and providing sulfide-free biogas. This study details the establishment of sulfidogenesis on the thermophilic DF of sugarcane vinasse in a continuous polyurethane-filled fixed-film reactor, also estimating the EP for vinasses according to different AD-related approaches. High sodium levels naturally stimulated SRB by maintaining high pH values (> 6.0), whilst NaHCO3 dosing was required when natural buffering conditions were not maintained. High acetate (~ 3 g-COD L−1) and COD/sulfate ratio (> 25.0) levels indicated a high-quality substrate for further methanogenesis. High butyrate concentrations (~11 g-COD L−1) coupled to caproate detection indicated the occurrence of chain elongation processes, leading to low bioH2 production levels (

The bacteria isolated from Hymeniacidon heliophila sponge cells showed bioleaching activity. The most active strain, Hyhel-1, identified as Bacillus sp., was selected for bioleaching tests under two different temperatures, 30°C and 40°C, showing rod-shaped cells and filamentous growth, respectively. At 30°C, the bacteria secreted substances which linked to the leached copper, and at 40°C metallic nanoparticles were produced inside the cells. In addition, infrared analysis detected COOH groups and linear peptides in the tested bacteria at both temperatures. The Hyhel-1 strain in presence of electronic waste (e-waste) induced the formation of crust, which could be observed due to bacteria growing on the e-waste fragment. SEM-EDS measurements showed that the bacterial net surface was composed mostly of iron (16.1% w/w), while a higher concentration of copper was observed in the supernatant (1.7% w/w) and in the precipitated (49.8% w/w). The substances linked to copper in the supernatant were sequenced by MALDI-TOF-ms/ms and identified as macrocyclic surfactin-like peptides, similar to the basic sequence of Iturin, a lipopeptide from Bacillus subtilis. Finally, the results showed that Hyhel-1 is a bioleaching bacteria and cooper nanoparticles producer and that this bacteria could be used as a copper recovery tool from electronic waste.

Carbon dioxide can be used as feedstock to produce chemicals. It represents a stimulating defiance to manufacture novel cost competitive materials with less environmental impact, besides to investigate new opportunities for catalysts and industrial chemistry. The contribution of carbon dioxide conversion goes beyond lowering global warming, by reducing fossil resource depletion or even yielding more benign production pathways. Albeit promising, the literature data regarding the quantity of energy needed to convert carbon dioxide into chemicals is limited and narrowed to the most studied processes and products. In order to understand and model the formation of species using carbon dioxide as raw material, some basic thermodynamic data are needed. The development of detailed reaction schemes in the field is also scarce. To enhance and further complete the database of the products obtained from carbon dioxide, this study investigates different procedures to estimate the basic thermodynamic properties of the reactants and products of these reactions. To date various methods have been developed and introduced to determine the gas-phase standard enthalpies of formation and Gibbs energy. Among them, group additivity and semi-empirical methods are widely employed due to their accuracy and effort time for implementation compared to more rigorous methods. Semi empirical quantum-chemistry methods were compared with group additivity methods. Available literature data were used to select the best method for property estimation of the whole set of species, whereby produced from carbon dioxide. The products from carbon dioxide were categorized in sixteen chemical classes, the reaction enthalpy for the direct route to manufacture the products were assessed and indicate a large difference among the classes. The results of this investigation show that semi empirical quantum-chemistry methods revealed to be more accurate for the studied species; additionally, the method demonstrates robustness in estimating the properties. Together, these results provide important insights into the thermodynamics of carbon dioxide related products.

2030-12 Emerging pollutants have been the subject of worldwide study because their continuous entry into the environment presents a risk to ecosystems and human health. Advanced oxidation processes show promise for eliminating or reducing the concentrations of emerging pollutants in water. This study aimed to investigate the treatment of aqueous systems containing the synthetic hormone 17α-ethinylestradiol. An innovative method for persulfate activation catalysed by ironmodified diatomite (heterogeneous system) was compared to conventional homogeneous activation methods (iron activation, alkaline activation, and heat activation). Iron-modified diatomite was more efficient in activating persulfate than traditional processes, achieving 98% of pollutant removal. Experimental results indicated that the catalyst can be reused without loss of removal efficiency, with potential environmental and economic benefits

The past decades have seen a diversification of the sugarcane industry with the emergence of new technology to produce bioenergy from by-product and waste process streams. Given Brazil’s ambitious goal of reducing green-house gas emissions by over 40% below 2005 levels by 2030, it is of paramount importance to develop reliable decision-making systems in order to stimulate investment in these low-carbon technologies. This paper seeks to develop a more accurate optimization model to inform risk-conscious investment decisions for bioenergy generation capacity in sugarcane mills. The main objective is for the model to enable a better understanding of how Brazilian government policies, such as the electricity price in the regulated market, may impact these investments, by taking into account the uncertainty in sugar, ethanol and spot electricity markets and the interdependency between production and investment decisions in terms of saleable product mix. The proposed methodology combines portfolio optimization theory with superstructure process modeling and it relies on simple surrogates derived from a detailed sugarcane plant simulator to retain computational tractability and enable scenario analysis. The case study of an existing sugarcane plant is used to demonstrate the methodology and illustrate how the model can assist decision-makers. In all of the scenarios assessed, the model recommends investment in extra bioelectricity capacity via the anaerobic digestion of vinasse but advises against investment in second-generation ethanol production via the hydrolysis of surplus bagasse. Furthermore, the decision to upgrade the cogeneration system with a condensation turbine is highly sensitive to the electricity price practiced in the regulated market, capacity constraints on the sugar-ethanol mix, and the accepted level of risk. Another key insight drawn from the case study is that recent market conditions have favored a production focused on the sugar business, making it challenging for policy-makers to create attractive scenarios for biofuels. Long-term electricity contracting appears to be the main hedging strategy for de-risking other products and investments in the sugarcane business, provided it is priced adequately.

Proteomic analysis of the fungus Aspergillus niger showed that its capacity to absorb metals was boosted by physiological modification under metal stress conditions. To investigate the proteome elicited by copper stress, the mine-isolated strain A. niger IOC 4687 was cultured in the absence (control) or presence of copper ions (50 mg L−1) for 72 h. Protein extract from each treatment was analyzed by nano-liquid chromatography-mass spectrometry and proteins were identified using PEAKS Studio 8.5 software. Grouping proteins by functional category showed that antioxidant enzymes, such as catalase, superoxide dismutase, and cytochrome c peroxidase, were present in both treatments. However, heat shock proteins (Hsp60 and Hsp70) and some metalloproteins (LMBR1 domain protein and A. niger contig An09c0040) were only observed after copper treatment. These proteins were the cellular response to the stress conditions. In conclusion, significant changes in the proteome of A. niger were observed due to the presence of copper.

Several international agreements, focused on regulating greenhouse gases emissions in the atmosphere, were created due to the growing concern about the climate change due to human action. The carbon dioxide (CO2) emissions account for more than 70% of the total greenhouse gases emissions; among the CO2 emitting sectors, electricity generation accounts for 25% of the global emissions. CO2 emissions from Brazilian power plants motivated their mapping, a method was proposed to performance a local market analysis for potential products from CO2 chemical conversion. The forecast behavior of this market for 2030 was also calculated. Among the studied products, methanol, polycarbonates, formic acid and acetaldehyde are the most promising for local manufacture. The States of Sao Paulo, Parana, Amazonas, Bahia, Rio Grande do Sul and Santa Catarina are the most promising regions in terms of potential of CO2 utilization.

The present study investigated the effect of contact time, the initial concentration of metal ions, and the biomass dose on the Cu(II) biosorption from an aqueous solution using dead biomass of filamentous fungus Penicillium ochrochloron, which was isolated at the Sossego mine, a copper-contaminated site located in Canaã dos Carajás city, Brazil. The Cu(II) biosorption started rapidly and increased gradually until the equilibrium was reached at 20 min. The Cu(II) uptake decreased as the initial Cu(II) concentration increased, reaching the saturation at 200 mg/L. The Cu(II) biosorption was considerably higher using 0.2 g than 0.5 g of the biomass in 50 mL of solution. The average biosorption capacity of Cu(II) was 7.53 mg/g and the maximum Cu(II) removal 75.0%. The Freundlich and Langmuir isotherm models adequately described the adsorption data. Our results evidenced that the dead biomass of P. ochrochloron has a great potential as a biosorbent to remove copper from an aqueous solution. Therefore, it could be explored for the development of the environmental recovery process.

An innovative application of the anaerobic structured-bed reactor (AnSTBR) in thermophilic dark fermentation of sugarcane vinasse targeting biohydrogen (bioH2) production was assessed. A detailed metabolite monitoring program identified the major substrates and primary metabolic pathways within the system. Increasing the applied organic loading rate positively affected bioH2 production, reaching 2074 N mL-H2 L−1 d−1 and indicating an optimal load of approximately 70 kg-COD m−3 d−1. Controlling the fermentation pH (5.0–5.5) was the primary strategy to maintain bioH2-producing conditions, offsetting negative impacts associated with the compositional variability of vinasse. Metabolic correlations pointed out lactate as the primary substrate for bioH2 production, indicating its accumulation as evidence of impaired reactors. The versatility of the acidogenic system was confirmed by identifying three major metabolic pathways according to the pH, i.e., lactate-producing (pH 6.0) systems, which enables managing the operation of the reactors for diversified purposes in practical aspects.

Metal contamination exerts environmental pressure on several lifeforms. Since metals are non-biodegradable and recalcitrant, they accumulate in living beings and spread through the food chain. Thus, many life forms are affected by environmental metal contamination, such as plants and microorganisms. In the case of microorganisms, scarce information is available on how metals affect them. As a highly resistant form of life, microorganisms can adapt to several environmental pressures through genetic modifications, changing their metabolism to overcome new conditions, and continuing to thrive in the same place. In this study, an Acinetobacter sp. strain was isolated from a copper mine, which presented very high resistance to copper, growing in copper concentrations of up to 7 mM. As a result of its metabolic response in the presence of 3 mM of copper, the expression of 35 proteins in total was altered. The proteins were identified to be associated with the glycolytic pathway, membrane transport, biosynthesis and two proteins directly involved in copper homeostasis (CopA and CopB).

The electrified plasma/liquid interface (PLI) induces the CO2 reduction (CO2R) by mediation of the solvated electron. Recent theoretical analysis of the chemical reaction network (chemical mechanism) revealed a 100% faradaic efficiency for CO2R [1] provided that the liquid surface was a flowing electrolyte; however, the theoretical analysis did not consider the proton concentration as a chemical variable, or the pH of the electrolyte so to speak, disabling to predict the distribution of products over the entire acid scale. For this reason, in this work, the proton has been categorically considered as a reactant and an essential variable for the dynamical model describing the CO2R via electrified PLI.Two new routes toward formic acid production are proposed namely the disproportionation-like (via-2) and radical cross-combination (via-3) reactions, see figure 1. Both consume the radical H formed by the scavenging of the solvated electron by the proton. The computational results reasonably matched the concentration ratio formate to oxalate around 3.0 for pH 2.45, which features the physical experiments [2]. This ratio would represent 25% selectivity toward formate at pH 2.45 for a flowing-electrolyte experiment. With this reasonably assertive mechanism, it was possible to predict that, at the same conditions of flowing electrolyte, an extremely acid pH (~1) would increase the selectivity toward formate, between 46 and 90% repectivelly for via-2 and via-3. Fig 1. Chemical reaction networks are shown in the LHS, and the predictions on the concentration ratio oxalate to formate are shown in the RHS for each path of formate synthesis (via–3 and via–2) and both combined. References [1] A. Mota-Lima, J.Phys. Chem. C, 124, 10907(2020). [2] P. Rumbach, R. Xu, and D. B. Go, J. Electrochem. Soc., 163, F1157 (2016). Figure 1

The presence of antibiotics and their metabolites in natural waters has raised some concern among scientists around the world because it can lead to bacterial resistance and other unknown consequences to mankind and wildlife. Persulfate (PS)-driven oxidation is a new technology that has been used successfully to remediate contaminated sites, but its use to treat wastewater, especially sewage treatment plant (STP) effluent, is still scarce. This paper describes the effect of several persulfate activation methods for degrading sulfathiazole (STZ) in Milli-Q water and in STP effluent. Some parameters, such as pH, persulfate concentration, presence of Mn2+, Zn2+, Cu2+, Fe2+, and Fe3+, as well as copper and iron organic complexes, were studied in STZ degradation. Raising the pH from 5 to 9, as well as the persulfate concentration, resulted in increased STZ degradation. Among the transition metals evaluated, only Fe2+ and Cu2+ were able to activate persulfate molecules. Copper was a better activator than iron since its effect lasts longer. Citrate was the best ligand evaluated increasing Fe(II) activation capacity at pH 7. Hydroxylamine addition to Fe(II) on persulfate system extended the Fe(II) effect. The presence of bicarbonate or humic acid did not affect PS-driven degradation of STZ. Finally, the degradation of STZ in STP effluent promoted by PS-driven oxidation (25 °C) was as fast as in Milli-Q water, proving to be successful.

Diversifying the portfolio of bioenergy-related products in sugarcane biorefineries is required to increase substrate conversion efficiency and market reach. The suitability of producing biohydrogen (bioH2) through the thermophilic dark fermentation of juice and molasses was assessed as an alternative to conventional sugarcane processing. The energetic potential of applying anaerobic digestion with phase separation to process molasses was also investigated. Molasses outperformed juice as substrate for continuous bioH2 production due to a more balanced nutrient content, whilst nitrogen deficiency directly hindered juice fermentation. An optimal COD/N ratio (∼100) could maximize bioH2 production from both juice and molasses. Continuous bioH2 production from molasses fermentation was optimized at pH and organic loading rate values of 5.38 and 86 kg-COD m−3 d-1, which are consistent with acidogenic systems inoculated with sugarcane vinasse-derived consortia. Metabolite profiles suggested that capnophilic lactic fermentation coupled to lactate-based butyrate production were the primary conversion pathways. Bioenergy generation from molasses (bioH2 + methane) exceeded that of vinasse by over 600 %, highlighting the relevance of anaerobic digestion as an efficient core processing step in the sucroenergetic industry. In particular, phase separation enhanced the total energy production by 13.1 % (604.30 vs. 683.76 MJ per ton of sugarcane) by maximizing the methane yield up to theoretical values.

Brazil's sugarcane sector is a significant source of employment, and operates at the intersection of energy, agriculture and land use. Its future development will be affected by the values, decisions and actions of key actors. Accordingly, we report on the results of qualitative semi-structured interviews with 19 participants with expertise in relation to Brazil's sugarcane sector. We used visual aids, and reflections on past events, to structure and contextualise discussions about the future prospects for the sector as a whole, and for four of its potential products – sugar, ethanol, electricity and biogas. Interviews revealed general expectations of continued growth in the sector, particularly for its energy-related products. However, the possibility of future challenges and tensions is still evident. We suggest three inter-related areas for ongoing reflection. First, there may be value in balancing the desire for minimal intervention, technology neutral styles of policy, with the need for policy that is clear, long-term and impactful. In some cases, more targeted policies for particular actors or emergent technologies, may also be justified. Second, increased clarity on the broader objectives for the sector, including the relative prioritisation of economic, social and environmental objectives, may help industry to make the long term investments consistent with the kind of deep innovation for which there is potential. Third, it is worth reflecting on how the above issues in combination can be leveraged into a global leadership strategy, with consideration of the relative robustness of different leadership strategies within broader emerging global dynamics.

Electrosynthesis via electrochemical plasma, a discharge over the surface of liquid water (or plasma cathode), may offer an unprecedented route of synthesis for chemicals and (wind) solar fuels. Describing the physical chemical events underneath plasma/liquid interface (PLI) on a theoretical basis is crucial for enabling a rational designing of chemical synthesis. To address this problem, this work proposes a generalist dynamical model for the nanoreactor, a fraction of nanoliters localized beneath the PLI that features substantially high concentration of hydrated electrons (eaq−), and it screens chemical reaction networks (CRN) related to the synthesis of hydrogen, a model electrosynthesis process. The computational results elucidate two major routes for hydrogen production: (a) in very alkaline media, the water reduction via self-recombination of eaq− [2eaq− + 2H2O → H2 + 2OH−] consumes the majority of eaq−, whereas (b) in very acid media, eaq− is majorly scavenger by the ion Haq+, generating an abnormally high concentration of the radical H•, a precursor for gaseous hydrogen. Additionally, two scenarios are disadvantageous for synthesizing H2. Side reactions with aqueous oxygen and aqueous radical • OH leads to substantial production of O2 − and OH−, respectively. Without loss of generality, the dynamical model proposed in this work is a powerful theoretical frame for understanding and predicting a variety of plasma-induced CRNs, assisting to advance the emerging field of plasma electrochemistry

Acetylsalicylic acid (ASA) is a model pollutant and a representative of the emerging pharmaceutical micropollutants whose mineralization across several advanced oxidative processes takes hours to complete. This work devotes to optimize and understand the kinetic conditions to mineralize ASA using Photo-Fenton process with UVA radiation in a tubular photochemical reactor. The optimization employs a statistical tool termed factorial design (FD) that studies how the concentrations of ASA, Fe2+ and H2O2 affects the mineralization over a larger interval of concentrations. The factorial design indicates that the initial concentration of H2O2 is a crucial variable to achieve a fast rate of ASA mineralization. Using optimized contents of both H2O2 and Fe2+ (45 Mm and 1.5 mM, respectively) in the Photo-Fenton process (H2O2/Fe2+/UVA), mineralization around 90% is reached in about 10 min, the fastest rate ever observed, enabling to treat 0.012 m3 h−1 per tubular reactor. The underlying reason for such outstanding performance is attributed to the optimized 4.5-folds excess of [H2O2], i.e. the ratio of H2O2 concentration used at the initial time to that required for complete mineralization of the theoretic TOC. Measurements of the remaining concentration of H2O2 strongly indicates that excess of [H2O2] optimizes the instantaneous concentration of radical OH. As a conclusion, the stoichiometric excess of [H2O2] is an important parameter to be optimized for achieving the highest degree of mineralization at the shortest time when using the photochemical reactor, in turn, decreasing costs related to the total energy consumed both by the lamp and by the recirculation pump.

The human exposure to bisphenol A (BPA) occurs frequently. Once, this compound was one of the highest volume chemicals produced worldwide and used as a plasticizer in many products. However, even at low concentration, it can cause severe damage to the endocrine system because of its endocrine disruptor activity. Thus, mitigation studies to remove or reduce this contaminant from the environment are essential. An alternative method of removing it from the environment is the use of bioremediation processes to the selected bacteria isolated from a BPA-impacted area. In this work, four halotolerant strains were isolated from the Santos Estuary System, one of the most important Brazilian examples of environmental degradation. In the present work, one strain presented strong BPA tolerance and high BPA-degrading activity and could grow in a minimum medium containing BPA as the main carbon source. Strain MH137742 was identified as Shewanella haliotis, based on 16S rRNA gene sequencing and mass spectrometry identification by MALDI-TOF Biotyper. Shewanella haliotis was able to tolerate up to 150 mg L−1 of BPA and biotransform 75 mg L−1 in 10 h in a liquid culture medium. Based on the analysis of the produced metabolites by LC-MS, it was possible to predict the metabolic pathway used by this microorganism to degrade the BPA.

An innovative sustainable protocol of nanobiotechnology has been developed to synthesize Ni/NiO magnetic nanoparticles, nanostructured in film form, through a dead organic matrix of the yeast Rhodotorula mucilaginosa, which was isolated from the Amazon region. It is a synergistic strategy that utilizes green technology, thus minimizing environmental impact and reducing costs. The best conditions for the adsorption of the metal through the dead organic matrix and subsequent synthesis of the nanoparticles were monitored by analyzing the biosorption of nickel by the yeast. The structural characteristics of the film-forming nanoparticles were investigated via high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FTIR). The magnetic properties of the nanoparticles produced by the dead organic matrix were determined in a superconducting quantum interference device (SQUID). Results indicate that the Ni/NiO nanoparticles are mainly spherical, with an average size of 5.5 nm, present magnetic properties, synthesized extracellularly and involve the proteins of the yeast, which probably confer organization in the film form. Such natural bioprocess suggests a rational protocol strategy as a template for the industrial-scale synthesis of magnetic nanoparticles of metals from the dead organic matrix of yeast and also provides a possible green system of nanobioremediation of metals from wastewater.

The methylotrophs bacteria can use methane and methanol as carbon sources to produce biopolymers including the polyhydroxybutyrate (PHB) a very promised substitute for the environment contaminant oil-derived polypropylene. This kind of bacteria can be very effective to help to decrease PHB price production and promote its use in substitution of several environment contaminant plastics. The search for methylotroph bacteria able to produce PHB is a very arduous job being necessary to grow all isolates and submit all of them to extraction processes and product characterization. Looking for time reducing and optimization of resources, we tested the Matrix Assisted Laser Desorption/Ionization technique (MALDI-Biotyper) to identify polymer producer bacteria based on a single isolated colony with success. The results showed here will contribute to speed-up and increase the discoveries of new bacteria strains able to produce PHB and other biopolymers.

An innovative diatomite-supported iron catalyst has been developed by using an impregnation process with a mixture of ferrous (Fe2+) and ferric (Fe3+) ions in the form of precipitated iron hydroxides. Raw and modified diatomite samples have been characterized by X-ray fluorescence and scanning electron microscopy. The main characterization results have revealed that modified diatomites are amorphous and have higher iron concentrations than raw diatomite. The results also indicate that the modified materials provided significant catalytic activity on phenanthrene degradation by using sodium persulfate. Satisfactory results were obtained with 45 g/L of sodium persulfate and 1 g of modified diatomite, thus degrading 98% of phenanthrene during 168 h of treatment. Kinetic and statistical approaches were developed for the remediation process herein, which have been validated with experimental data, thence yielding suitable results.

Recentemente, o uso de persulfato em processo de oxidação química in situ em áreas contaminadas por compostos orgânicos ganhou notoriedade. Contudo, a matriz sólida do solo pode interagir com o persulfato, favorecendo a formação de radicais livres, evitando o acesso do oxidante até o contaminante devido a oxidação de compostos reduzidos presentes no solo ou ainda pela alteração das propriedades hidráulicas do solo. Essa pesquisa teve como objetivos avaliar se as interações entre a solução de persulfato com três solos brasileiros poderiam eventualmente interferir sua capacidade de oxidação bem como se a interação entre eles poderia alterar as propriedades hidráulicas do solo. Para isso, foram realizados ensaios de oxidação do Latossolo Vermelho (LV), Latossolo Vermelho Amarelo (LVA) e Neossolo Quartzarênico (NQ) com solução de persulfato (1g/L e 14g/L) por meio de ensaios de batelada, bem como a oxidação do LV por solução de persulfato (9g/L e 14g/L) em colunas indeformadas. Os resultados mostraram que o decaimento do persulfato seguiu modelo de primeira ordem e o consumo do oxidante não foi finito. A maior constante da taxa de reação (kobs) foi observada para o reator com LV. Essa maior interação foi decorrente da diferença na composição mineralógica e área específica. A caulinita, a gibbsita e os óxidos de ferro apresentaram maior interação com o persulfato. A redução do pH da solução dos reatores causou a lixiviação do alumínio e do ferro devido a dissolução dos minerais. O ferro mobilizado pode ter participado como catalisador da reação, favorecendo a formação de radicais livres, mas foi o principal responsável pelo consumo do oxidante. Parte do ferro oxidado pode ter sido precipitado como óxido cristalino favorecendo a obstrução dos poros. Devido à maior relação entre massa de persulfato e massa de solo, a constante kobs obtida no ensaio com coluna foi 23 vezes maior do que a obtida no ensaio de batelada, mesmo utilizando concentração 1,5 vezes menor no ensaio com coluna. Houve redução na condutividade hidráulica do solo e o fluxo da água mostrou-se heterogêneo após a oxidação devido a mudanças na estrutura dos minerais. Para a remediação de áreas com predomínio de solos tropicais, especialmente do LV, pode ocorrer a formação de radicais livres, mas pode haver um consumo acentuado e não finito do oxidante. Verifica-se que o pH da solução não deve ser inferior a 5 afim de evitar a mobilização de metais para a água subterrânea e eventual obstrução dos poros por meio da desagregação dos grãos de argila. Recently the persulfate application for in situ chemical oxidation at areas contaminated by organic compounds gained notoriety. However, the persulfate can interact with the solid matrix of the soil favoring the formation of free radicals, avoiding the oxidant access to the contaminant due to the oxidation of reduced compounds present in the soil or by changing the hydraulic properties of the soil. This research aimed to evaluate if the interactions between the persulfate solutions and three Brazilian tropical soils could eventually interfere on the persulfate oxidation capacity and if the interaction between them could modify the hydraulic properties of the soil. For such, oxidation tests were performed with soils: Latossolo Vermelho (LV), Latossolo Vermelho Amarelo (LVA) and Neossolo Quartzarênico (NQ) with persulfate solution (1 and 14 g/L) through batch tests and LV oxidation by persulfate solution (9 and 14 g/L) on undisturbed columns. The results showed that persulfate decay followed a first order model and oxidant consumption was not finite. The higher reaction rate coefficient (kobs) was observed in the reactor with LV. This higher interaction was due to the difference in the mineralogical composition and surface area. Kaolinite, gibbisita and iron oxides showed greater interaction with persulfate. The pH reduction on the reactor solution caused the aluminum and iron leaching due to dissolution of minerals. The mobilized iron may have participated as a reaction catalyst favoring the formation of free radicals although it was the major responsible for the oxidant consumption. Part of oxidized iron may have been precipitated as crystalline oxide favoring the clogged pores. As a consequence of the higher mass proportion between persulfate and soil, the kobs constant obtained in the column test was 23 times higher than the one observed on the batch test, even utilizing a concentration 1.5 times lower than bath test. There was a reduction in the soil hydraulic conductivity and the water flow proved to be heterogeneous after oxidation due to changes in minerals structure. For remediation purposes in areas with predominance of tropical soils, especially LV, the formation of free radicals may occur but an accented and not finite oxidant consumption may happen. It is verified that the pH solution should not be inferior than 5 to prevent the mobilization of metals to the groundwater and a possible pores clogging by the breakdown of the clay grains.

Polychlorinated biphenyls (PCB) are chlorinated organic substances which are highly toxic and also considered persistent organic pollutants (POP). It should be emphasized the environmental importance for treating wastes with PCB. For instance, Stockholm convention on POP established the elimination of the use of PCB in equipments, e.g., electrical transformers and capacitors, by 2025. The decontamination of materials containing PCB may be performed by supercritical extraction technology using carbon dioxide (CO2) as solvent. The first objective of this work was the formulation of a computational tool to correlate solubility data of aromatic compounds in supercritical CO2, using Peng–Robinson equation of state. In a second step, a description of Askarel oil, like Araclor 1254, solubility in supercritical CO2 was provided for simulation purposes of the extraction process. PCB mixture has predominance of congeners: tetra, penta, hexa, heptachloro biphenyl, tri and tetrachlorobenzene. The calculation procedure was initially applied for a series of aromatic compounds (naphthalene, biphenyl, anthracene and phenanthrene) in order to validate the approach. Experimental solubility data collection has been elaborated from the literature, providing a systematic series of the studied aromatic compounds with CO2. The binary parameters for the classical van der Waals quadratic mixing rule (vdW2) were systematically estimated, together with a new set of Clausius–Clapeyron solute vapor pressure in order to describe the temperature dependence and achieve experimental solubility uncertainties. Finally, the estimated parameters were used to simulate solubility values of Askarel oil as function of the operational conditions of extraction by a simultaneous solution of the equilibrium equations for each compound. The thermodynamic modeling demonstrated to be feasible for process analysis and design.

Zinc aluminate (ZnAl2O4) particles with a spinel structure were prepared by metal-chitosan complexation method. The solids were obtained by the thermal decomposition of precursor compound of metallic hydroxides mixture and the biopolymer chitosan. X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and N2-adsorption–desorption isotherms were used for the characterization of the products. The results showed that the ZnAl2O4 spinel can be obtained by heating the precursor at temperatures above of 500 °C, resulting in a material with porous structure and large surface area and high purity.

The anaerobic processing of sugarcane vinasse has been recently highlighted as an effective approach to both mitigate negative impacts of its inadequate management and recover renewable energy through biogas production. However, basic aspects of the process still require further investigations, such as understanding the impacts of the compositional variability of vinasse on the overall performance of anaerobic systems. In this context, the impacts of different types of sugarcane vinasse, i.e., from annexed (VinAn) and autonomous (VinAu) ethanol plants and spirit production (VinAl), on methane production and organic matter removal were assessed under mesophilic conditions (37 °C) from a kinetic perspective. The energetic potential of the biogas was also investigated regarding micro (methane yield) and macro (contributions to the Brazilian energy matrix) scales. The availability of biodegradable organic matter and sulfate had a direct impact on the kinetics of methane production, associating a 2-fold higher initial methane production rate with VinAl (10.12 NmL h−1) compared to VinAn (5.95 NmL h−1) and VinAu (4.25 NmL h−1). However, the methane yield was not affected by the compositional variations (328–339 NmL-CH4 g−1COD), which indicates that vinasse may be efficiently used as substrate for bioenergy generation, regardless of its origin. The global energy production estimated for VinAn (24,816 GWh) was over 6- and 7-fold higher compared to VinAu (3984 GWh) and VinAl (3035 GWh) due to discrepancies in vinasse generation flow rates, potentially increasing the available renewable power supply in Brazil by 2.2% or over 1400% of the current bioenergy produced from biogas. Overall the electric energetic potential of sugarcane vinasses (14,486 GWh) could replace over 20% of natural gas or 90% of coal use in Brazil, satisfactorily decreasing the dependence on non-renewable energy sources.

An artificial neural network (ANN) was implemented for modeling phenol mineralization in aqueous solution using the photo-Fenton process. The experiments were conducted in a photochemical multi-lamp reactor equipped with twelve fluorescent black light lamps (40 W each) irradiating UV light. A three-layer neural network was optimized in order to model the behavior of the process. The concentrations of ferrous ions and hydrogen peroxide, and the reaction time were introduced as inputs of the network and the efficiency of phenol mineralization was expressed in terms of dissolved organic carbon (DOC) as an output. Both concentrations of Fe2+ and H2O2 were shown to be significant parameters on the phenol mineralization process. The ANN model provided the best result through the application of six neurons in the hidden layer, resulting in a high determination coefficient. The ANN model was shown to be efficient in the simulation of phenol mineralization through the photo-Fenton process using a multi-lamp reactor.

This study presents the results of an analysis of crude oil and asphaltene samples using the MALDI TOF technique. Thirty crude petroleum samples (24.53–32.05 API gravity) obtained from a Brazilian refinery were used in this study. Asphaltenes were precipitated from the corresponding crude oil samples with n-heptane. Mass spectra were acquired with a MALDI TOF mass spectrometer in a mass range of 100–1000 Da. The main purpose of this study was to analyze the composition of the asphaltene molecules extracted from oil samples according to their molecular composition (molecular weight and composition heteroatoms). The mean composition of the group analyzed was calculated as follows: 17% sulfur-containing molecules, 28% nitrogen-containing molecules, 19% oxygen-containing molecules, 12% sulfur–oxygen-containing molecules and 17% nitrogen–oxygen containing molecules; only 7% of the compounds contained only hydrogen and carbon in their composition. Finally, MALDI TOF analysis can be a very efficient process with a great potential for estimating the physicochemical properties of asphaltenes. A VBA (Visual Basic for Applications) algorithm allowed us to determine the elemental composition of components of asphaltene samples. The elemental composition showed that, despite having the same physical characteristics, the chemical composition of the samples was different.

CuO/ZnO coupled oxide films were electrodeposited onto an aluminum substrate and tested as photocatalysts in degradation of phenol molecules in aqueous solution under sunlight. The obtained films were characterized by X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results showed that the photocatalytic activity of films was significant, especially to coupled oxide film with a CuO/ZnO ratio equal to 0.697, which presented about 70% degradation of the aromatic molecules and 42% of total organic carbon (TOC) removal at 300 min under solar irradiation. Therefore, this work highlights the potential application of CuO/ZnO coupled oxide films obtained by electrodeposition onto aluminum substrate in the field of photocatalysis.

The purpose of this study was to extract alkaloids from Melocactus zehntneri aerial parts using supercritical fluid extraction (SFE) and to evaluate their cytotoxic action. SFE process was compared to different classical low pressure solvent extraction processes in terms of global yield, extract profile and biological activity. Two specimens of M. zehntneri were evaluated: young and adult aerial parts. The extracts were analyzed by HPLC-UV/DAD as well as they were evaluated against HMVII and Trichomonas vaginalis. The results indicated a qualitative difference in chromatographic profile of the extracts. Finally, the results point out the potential of the extract obtained from aerial parts of young specimens (Y-RM) through SFE at 300 bar/55 °C against T. vaginalis and HMVII, presenting relevant information for development of new studies about cytotoxic.