Ouricuri (Syagrus coronata) fiber: a novel biosorbent to remove methylene blue from aqueous solutions.

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L-1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g-1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.

Synthesis of layered double hydroxides: Investigating the impact of stirring conditions and reactor design parameters.

The synthesis by coprecipitation of Layered Double Hydroxides (LDHs) is governed by the stages of nucleation and crystal growth associated with the efficiency of the mixing and dispersion process of the reagents. Mixing efficiency is related to process variables, such as agitation speed, type of impeller and baffles presence, among others. In this context, this work proposes an analysis of these variables in a batch reactor, using a 23 factorial design employing the factors: acceleration speed (200 and 1000 rpm), mixing time (2 and 18 h) and presence or absence of baffles. The results were evaluated quantitatively (amount of LDH produced, time and amount of base for the formation of LDHs to begin) and qualitatively (mixing aspects, sedimentation ad grinding). The significant factors affecting the amount of LDH produced (51.94-80.81 g) were agitation speed and aging time. These factors were also correlated with the structural characteristics of the materials produced, such as crystallinity, crystallite size (70.99-174.79 nm), surface area (69.81-97.62 m2/g), pore volume (0.28-0.59 cm3/g), and pore diameter (11.40-34.66 nm). LDHs produced at higher agitation rates (1000 rpm) and longer aging times (18 h) yielded higher quantities of materials (80.81 g) with improved structural characteristics. The study highlights the importance of systematically exploring the synergistic effect between process variables, emphasizing the research potential in this area.

Influence of phenolic compounds on color formation at different stages of the VHP sugar manufacturing process.

Phenolic compounds are natural dyes contained in sugarcane juice and represent an important parameter in industrial processing, as they significantly affect the color formation of raw sugar. This study investigated the relationship between color formation and phenolic compounds during a Very High Polarization (VHP) sugar manufacturing process, in which the RB92579 genotype represents about 50% of the processed sugarcane. The products evaluated during the industrial processing of sugarcane were: raw juice, mixed juice, lime-treated juice, clarified juice, syrup, massecuite, and VHP sugar. The polyphenols catechin (CAT), chlorogenic acid (CGA), caffeic acid (CAF), vanillin (VAN), syringaldehyde (SYR), p-coumaric acid (p-COU), coumarin (CUM), and rutin (RUT) were quantified by high-performance liquid chromatography (HPLC). The highest concentrations of CGA and SYR were obtained from the sucrose crystallization product (massecuite), similarly to the parameters of color, total phenols and the total polyphenol content. CGA was the predominant polyphenol in the samples of clarified juice, syrup, massecuite and VHP sugar, with the latter presenting concentrations above 50%. The presence of phenolic compounds provided different indices of color during the production process. In this context, chlorogenic acid (CGA) was the compound that presented the most expressive results, contributing significantly to the formation of color in sugarcane processing products, which is a fact that has not yet been reported in the literature. The color of the VHP sugar crystals also had a positive relationship with the concentration of phenolics, with greater evidence for CGA.

Oil impact on the environment and aquatic organisms on the coasts of the states of Alagoas and Sergipe, Brazil - A preliminary evaluation.

The oil spill off the coast of the Brazilian Northeast region is one of the most significant global events regarding contamination and environmental impact in recent years. This work evaluates the effects of oil spills on the Northeast coasts between Alagoas and Sergipe states from October 2019 to January 2020. Analysis of some sampling points of seawater revealed the presence of Hg, Cd, Pb, and Cu in levels above the maximum concentration limits established by the Brazilian legislation. For water quality parameters, phosphorus, nitrite, and turbidity showed statistically different values. However, the chromatographic profiles of oil obtained from different beaches were quite similar. Seawater, fishes, and massunins (bivalve) presented the main polycyclic aromatic hydrocarbons: naphthalene, phenanthrene, fluoranthene, fluorene, and acenaphthalene. Therefore, the concentration of organic and inorganic contaminants determined in different environmental locations served as a subsidy to assess the effect of the preliminary oil spill on the Brazilian coast.

Coalescence process to treat produced water: an updated overview and environmental outlook.

Produced water is the largest liquid effluent in volume generated in petroleum production. It originates from natural wells or from water that was previously injected during the exploration process. The composition of produced water is complex, containing high salt concentration, emulsified oil, suspended solids, chemical additives used in the various stages of oil production, heavy metals, and other contaminants. Several technologies can be used in the treatment of produced water in order to meet the conditions specified in local legislations and the most used are phase separators, decanters, cyclones, and filters. The separation process mechanism of oil emulsions by coalescence in fibrous media has excellent results, though it is not fully understood and is frequently based on empirical, as well as on experimental, observations. This article presents a general overview on produced water, including origin, production, composition, environmental impact, treatment techniques, disposal, and legislation, as well as an updated discussion utilizing recent literature regarding the unit operation of coalescence: general aspects, kinetics, mechanisms, and factors that influence the coalescence process.

Syagrus oleracea-activated carbon prepared by vacuum pyrolysis for methylene blue adsorption.

This work aims to produce activated carbon from the endocarp of Syagrus oleracea by vacuum pyrolysis and evaluate its potential as an adsorbent. The effects of pyrolysis temperature (400 °C, 500 °C, 600 °C, and 700 °C), particle diameter (0.467 mm, 0.267 mm, and lower than 0.234 mm), and activation agent (H2SO4, H2PO3, and KOH) on the potential for methylene blue adsorption were investigated. In addition, kinetics and adsorption equilibrium were evaluated. The best condition found was particle diameter < 0.234 mm, final pyrolysis temperature of 700 °C, and using KOH. Adsorption kinetics followed pseudo-second order, with equilibrium reached within 20 min. Isotherms followed the Freundlich model. Values of adsorption capacity were in the order of 30 mg/g. Thermodynamic parameters indicated that adsorption occurred spontaneously with a reduction in the heterogeneity of the solid interface/solution. The results obtained demonstrate the great adsorption capacity of the activated carbon prepared from endocarp of Syagrus oleracea via vacuum pyrolysis for the removal of up to 98% methylene blue from aqueous solutions.

Wodyetia bifurcata biochar for methylene blue removal from aqueous matrix.

The endocarp of Wodyetia bifurcata was used to produce biochar by vacuum pyrolysis as an alternative adsorbent for methylene blue (MB) removal. The influence of different pyrolysis temperatures, particle diameters and activation agents in the adsorption process was studied. Kinetics and adsorption equilibrium were also evaluated. Biochar obtained at higher pyrolysis temperatures and activated with H3PO4 showed the best adsorptive capacities, achieving 83% of MB removal. The experimental data fitted better with pseudo-second order model. Isotherms performed at 25, 40, 50 and 60 °C showed that the adsorption of MB onto the activated biochar had no concentration dependence in the range studied. Experimental isotherms fitted well with the Freundlich and Sips models and the thermodynamic parameters suggested a physical adsorption mechanism in a heterogeneous surface, spontaneous at all temperatures evaluated. In brief, the activated carbon obtained from Wodyetia bifurcata can be a promising material for MB removal from aqueous solutions.

Pyroligneous extracts with therapeutic action: A technological prospect

Abstract The Pyroligneous extract is a product from the combustion of plant biomass with applications in the fields of health, industrial chemistry, and agriculture. The discovery of new molecules with therapeutic potential and of natural origin continues to be one of the great challenges for research centres around the world. The following work aims to analyze, through a technological prospection, the use of pyroligneous extracts for therapeutic purposes. To carry out the study, searches were carried out in documents deposited in Brazil, Europe, and the United States and searched on platforms specialized in patents. The number of inventions using pyroligneous extract with therapeutic applications is still quite small, however, innovations have been observed for the treatment of diseases of great clinical relevance such as cancer and hypertension. The systematic mapping of innovations is of great importance for the development of new technologies.

Kinetics, isotherm, and thermodynamic studies of methylene blue adsorption from water by Mytella falcata waste.

This work evaluates the application of Mytella falcata shells, discarded in large quantities in the state of Alagoas, Brazil, as adsorbent for methylene blue dye (MB). It was investigated how the amount of adsorbent (M), the average particle diameter (G), and the agitation speed (A) affected the adsorption. Kinetic and equilibrium studies were conducted, and the pseudo-second-order equation adequately represented the kinetic data and isotherms following Liu's model (q max = 8.81 mg g-1 at 60 °C). The adsorption was spontaneous, favorable, and endothermic. Mytella falcata shell is a suitable adsorbent for MB and could potentially contribute to its removal from the environment.