Despite the extensive literature on the effects of implementing aeration in the electrocoagulation (EC) treatment of industrial wastewater, few studies evaluate the performance of this technique at high aeration rates. In this work, we present the outcomes derived from EC treatment of pharmaceutical and synthetic textile wastewater effluents in two lab-scale reactors with and without aeration, each equipped with different electrode combinations of aluminium and iron (Al/Al, Al/Fe, and Fe/Fe). In the non-aerated EC reactor, maximum chemical oxygen demand (COD) reductions of 56% and 80% were achieved for the pharmaceutical and textile effluents, respectively, with up to 100% removal of turbidity and colour with the Al/Al combination. The installation of high-rate aeration to prevent sludge accumulation on the electrode surface markedly reduced residence times and enhanced the COD removal in the pharmaceutical effluent. However, this implementation potentially reduced the process efficiency for thesynthetic textile effluent as prolonged operation led to flocculation breakdown and subsequent re-dissolution of the contaminants in the water.

In recent years, dyes have been classified as recalcitrant contaminants in wastewater, exhibiting significant toxicological characteristics for flora, fauna, and humans. Various techniques are currently being studied for the remediation of water contaminated with dyes. Among the most relevant alternative technologies are bioadsorption, biocoagulation, the use of composite materials, advanced oxidation processes, etc. However, these methods have some disadvantages. Similarly, the use of hydrogels specifically designed for the treatment of contaminated water is a viable and effective alternative. This is due to their ability to adsorb large amounts of water, high porosity, and multiple active sites. This research describes dyes, their classification,toxicity, and ecotoxicity. Additionally, it presents some alternative treatments for water remediation, emphasizing the design of hydrogels based on synthetic and natural macromolecules. These hydrogels are proposed as promising materials for the removal of dyes from contaminated water. The aim of this research is to highlight synthetic and natural hydrogels as promising materials for the decontamination of water from dyes.

The presence of emerging contaminants, especially drugs for human and veterinary use in natural waters, due to their high degree of persistence and the fact that the treatments used in wastewater treatment plants (WWTP) are not efficient at removing them, has been the subject of study by the scientific community. In this work, the removal of ibuprofen from synthetic waters was studied working in an stirred tank using corn cob residues as a biosorbent. Aiming to achieve the highest drug removal rates, several parameters where studied such as: the concentration of biosorbent, the particle size of the biosorbent, the minimum contact time between both adsorbate and biosorbent to reach the equilibrium, the optimum pH and the temperature. The best conditions to remove ibuprofen (20 mg/L) from synthetic water were the use of 15 g/L of corn cobs with a particle size of 0.4191 mm stirring for one hour at pH 6.0. No matter the temperature, a removal rate of 50% was obtained after 10 minutes of contact,reaching an 89% at the equilibrium. A kinetic study showed that the pseudo-second-order kinetic model was the one that best reproduced the experimental data with a determination coefficient (R2) of 0.982, and for the equilibrium behavior, theFreundlich model was the best fit for the adsorption equilibrium data with a R2 of 0.972.

Evaluating the panela agroindustry as an alternative for profitability, viability and decision-making is a vital exercise from the point of view of sustained socioeconomic growth. For the socioeconomic evaluation of the agroindustry intensification, the Peters- Timmerhaus Excel spreadsheet was used. The evaluation included technical production diagnosis, mass balance and production costs of different panela factories depending on the grinding capacity: 10 to 30 tc/d (tons of cane per day) with four production alternatives and two drying variants. Results show that in an intensified panela agroindustry, the economic viability to recover the capital is reached in 2.5 years, with alternatives 1,2 and 4, the last one includes the production of three products (honey, panela and natural sugar) for 20 tc/d and 1.5 years for 30 tc/d using naturally dried bagasse as fuel. A comprehensive understanding of the production area and the interrelationships with other areas of the panela agroindustry allowed to refine possibleproduction lines and socialize the information for rapid decision-making with immediate application projection and revival of the sector, considering that the application of technologies and the intensification of processes improves quality, increases profitability, generates well-being and ensures food security.

An analytical method for the derivatization of fatty acids to methyl esters using basic catalysis with special emphasis on the identification of the different C18:1 trans isomers was developed and validated, showing excellent accuracy, precision and linearity. This method was employed to evaluate the degradation of palm olein during the deep discontinuous frying process of potatoes and bananas over 60 hours at different temperatures, simulating most habitual food processing methods used in El Salvador. It was observed that untreated oils already showed low levels of trans fatty acids (around 0.085%) although these products were marketed as if they did not contain any trans fats. As expected, the concentration of trans fatty acids in the oil increased throughout the deep-frying process, while contents in mono- and polyunsaturated fatty acids decreased. This degradation of the oil varied depending on the temperature and the amount of water of the product being cooked.

In any process, control plays a vital role in the quality of the product. The influence of a controller's operation on a process is linked to its success or failure. However, using a controller that works properly presents several obstacles, such as non-linearity or the lack of a model that adequately represents the behavior of the process. Different approaches have been devised and studied to deal with these difficulties. One of the most promising and widely applied and studied in recent years is fuzzy control due to its ability to operate systems with no precise plant model. Herein, a set of rules and a fuzzy control structure are proposed, with fewer design parameters than a conventional fuzzy controller and better performance. The global stochastic optimization tool Differential Evolution is used to obtain the design parameters of the proposed fuzzy controller.

To improve the recovery percentages in the analysis of PAH (polycyclic aromatic hydrocarbons) in natural waters, parameters such as standard stability, filtration, storage time and matrix effect were optimized for five PAH by HPLC-FD. For aqueous standards, with the addition of 10% acetonitrile, good linearity was found for naphthalene, acenaphthene, anthracene, pyrene, and chrysene curves up to the second day of standards preparation. In filtration, the best results were obtained using the AP10 and Nylon filters with 10% acetonitrile, with recovery ranges of 98-72% and 93-56%, respectively. In contrast, lower values were obtained with cellulose filters in a polyethylene holder without the addition of 10% acetonitrile with recoveries of 52-0%. A 23 factorial design established, for natural water, that the most important factors were: storage time for naphthalene and acenaphthene, with area losses at 48 hours and the use of organic solvent for anthracene, pyrene and chrysene, with area gain for 20 % acetonitrile. For liquid-liquid extraction in standards, recoveries of 62-45% were found in aqueous matrix without acetonitrile and 98-35% with 20% acetonitrile + 2.5% NaCl, at 24 hours of preparation.

The chemical composition of the essential oil from the aerial parts (leaves and flowers) of Tagetes filifolia Lag. grown in the Peruvian Andes was examined throughout the gas chromatography and gas chromatography-mass spectrometry techniques. Fifty-seven compounds were identified representing more than 99% of the essential oil. Phenylpropanoids had the major percentage, including (E)-anethol (85.0%) and estragole (12.9%) as the most abundant compounds. A multivariate analysis was performed using hierarchical cluster analysis to examine the relationship between the studied sample and other T. filifolia specimens from 21 essential oil compositions reported in the literature. Agglomerative hierarchical cluster analysis reveals three groups: (E)-anethole/estragole, estragole/(E)-anethole and an outlier (Z)-anethole/estragole. In addition, antioxidant activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl and ferric reducing antioxidant power assays. The essential oil had a moderate scavenging effect and ferric reducing capacity.

Juliá and Colonna were one of the firsts chemists reporting examples of enantioselective organocatalyzed reactions, namely the Phase-Transfer Catalysis (PTC) olefin epoxidation. Although some reviews exist on the Juliá-Colonna reaction, none is devoted specifically to it. After an introduction reporting the main publications gathered in three tables, this review is organized into a) olefin epoxidation; b) other enantioselective catalysts; c) Juliá-Colonna papers; d, e) papers citing the "Juliá-Colonna" epoxidation with special stress on those by Stanley M. Roberts. This review summarizes the papers by these authors and reports the most relevant improvements.