One of the biggest problems of water with high concentrations of calcium is its susceptibility to causing scaling in industrial equipment (boilers, heat exchangers, pipes, reverse osmosis membranes, storage tanks, etc.). The purpose of this study was to evaluate a recently built filter press (EC) type electrocoagulation reactor and investigate the efficiency of water hardness removal. The electrocoagulation (EC) reactor has been evaluated in batch mode using electrodes of aluminum (Al) and connected to a direct current power supply in a monopolar way. To evaluate the performance of the reactor, a synthetic solution with a concentration similar to that of brackish water was used. A factorial design was applied to investigate the influence of the electrical potential applied to the electrocoagulation cell at the levels of 3, 5, 7, and 9 V, and initial calcium hardness of 540.2 and 914.60 mg/L CaCO₃ at room temperature in 60 treatment minutes. The results revealed that the electrical potential applied to the electrocoagulation cell was the most significant factor in hardness removal, within the experimental ranges studied. The results showed that electrocoagulation at an electric potential applied at 9 volts and an initial concentration of 7400 mg/L allowed a higher hardness removal efficiency (25.83%). the pH of the solution increased throughout the process. The energy consumption ranged between 4.43 and 42 kW.h/m³ depending on the conditions of the factors. It has been shown that during the treatment process a layer of dense and compact calcium carbonate precipitate is formed on the surface of the cathode.

Vinasse is acidic, dark brown wastewater obtained as a residue from the alcohol distillation process, the main component of which is water, in addition to mineral nutrients and a high organic load. Electrocoagulation (EC) is a technology that generates coagulating substances in situ by oxidizing sacrificial anodes through an electric current applied to the electrodes. During the last decade, the electrocoagulation process has been intensively investigated in several reviews, due to its ease of operation, versatility, sustainability and low environmental impact. The objective of the present work has been to make a general review of the EC process, its principle, reaction mechanism and operating parameters involved in the electrocoagulation process. In this research, the PRISMA method was used for the analysis of articles from different databases such as Scopus, ScienceDirect and Google Scholar. This review collects numerous studies of the EC process in stillage wastewater treatment and makes a comparison between these experimental results mainly in terms of chemical oxygen demand removal. In addition, this review makes a comprehensive analysis of EC coupled to other processes, taking into account their operating parameters and stillage contaminant removal efficiency. The conclusion of this research points out that electrocoagulation coupled with other treatment processes is very necessary because it reduces energy consumption and increases the rate of pollutant removal from wastewater.

Hydrogen, as a clean energy source, has enormous potential in addressing global climate change and energy security challenges. This paper discusses different hydrogen production methodologies (steam methane reforming and water electrolysis), focusing on the electrolysis process as the most promising method for industrial-scale hydrogen generation. The review delved into three main electrolysis methods, including alkaline water electrolysis, proton exchange membrane electrolysis, and anion exchange membrane electrolysis cells. Also, the production of hydrogen as a by-product by means of membrane cells and mercury cells. The process of reforming natural gas (mainly methane) using steam is currently the predominant technique, comprising approximately 96% of the world’s hydrogen synthesis. However, it is carbon intensive and therefore not sustainable over time. Water, as a renewable resource, carbon-free and rich in hydrogen (11.11%), offers one of the best solutions to replace hydrogen production from fossil fuels by decomposing water. This article highlights the fundamental principles of electrolysis, recent membrane studies, and operating parameters for hydrogen production. The study also shows the amount of pollutant emissions (g of CO₂/g of H₂) associated with a hydrogen color attribute. The integration of water electrolysis with renewable energy sources constitutes an efficient and sustainable strategy in the production of green hydrogen, minimizing environmental impact and optimizing the use of clean energy resources.

The modeling and simulation of the catalytic dehydrogenation process of cyclohexanol in a fixed-bed catalytic reactor is presented, leading to finding the relationship between the effectiveness factor, the Thiele modulus, and the Weisz–Prater modulus of the catalyst particles with respect to their axial and radial position, for which the external conditions of concentration and temperature around each particle were previously obtained by applying the material and energy balances in the catalyst bed considering a two-dimensional pseudo-homogeneous model with radial diffusion. Subsequently, the material balances are established in terms of the molar flux density and conversion, the energy balance in terms of the heat flux density, Fick’s law, Fourier’s law, and the differential form of the effectiveness factor non-isothermal for each particle chosen based on the proposed meshing. The Thiele modulus calculated for most of the points is between 0.8 and 0.25, with a tendency towards the lower limit, and the theoretical values established as the limit for the Thiele modulus fluctuate between $0.4<T_h<4$. Therefore, the effectiveness factor analyzed is between 1 and $1/T_h$; this indicates that both the reaction speed as well as the diffusion speed within the particle have an influence on the intraparticle process, which is confirmed by the calculation of the Weisz–Prater modulus whose values are not $<<$1 nor $>>$1. The results obtained are subjected to a statistical test leading to analyzing whether there are significant differences both in the Thiele modulus, as well as in the effectiveness factor with respect to the radius and length of the reactor. It has been determined that there are no significant differences between the effectiveness factor with respect to the radius of the reactor; however, according to the analysis of variance, there are significant differences in the effectiveness factor with respect to length and, likewise, there are significant differences in the Thiele modulus and the Weisz–Prater modulus with respect to radius and length.

Brackish water is an important source of water resources with lower salt content than seawater. Desalination is a very important treatment to remedy the scarcity of fresh water throughout the world. In this work, it has been proposed to desalinate brackish groundwater using a commercial...

Currently, research on microplastics (MPs) has increased due to their rapid distribution throughout the world and their harmful effects on the ecosystem. However, a detailed description of their dispersion and the methods for both detection and removal has not been given. The objective of this research is to carry out a bibliographic review that allows for a multidisciplinary analysis of microplastic contamination and current detection and removal methods. The method used is PRISMA in which articles from reliable databases such as Scopus, Web of science, and Google Scholar were collected and analyzed to finally provide details on the physical and chemical methods for detecting MPs, in addition to presenting the technologies for their removal. As a result of the analysis, critical information was obtained from the different studies on the impact of MPs on the ecosystem and the variation in detection and removal efficiency according to the type of pretreatment and methods applied to the sample. It is concluded that this research is essential to understand the consequences that MPs have on the ecosystem and provide tools to evaluate and improve current technologies, mainly detection and removal.