Carlos Vereda-Alonso

Antimony and arsenic are two pollutants known for their bioaccumulative effects and toxic properties even in low concentrations, therefore there is a need to develop efficient and reliable extraction and preconcentration methods of these analytes in water systems simultaneously. In this work, an online ultratrace extraction and preconcentration methodology for environmental waters was carried out by combining magnetic solid phase extraction (MSPE), hydride generation (HG) and inductively coupled plasma mass spectrometry (ICP-MS). A novel anionic nanosorbent, called M@GONIO, based on graphene oxide and magnetic nanoparticles functionalized with ammonium groups was designed, synthesized, and characterized for MSPE. The developed method was carefully optimized through univariate analysis and response surface methodology based on a central composite design. Under the optimized conditions, the enrichment factors for As and Sb were 84.7 and 84.6, respectively. The intra-day and inter-day precision expressed as relative standard deviation (RSD) were below 5.1% in all the evaluated conditions. The proposed analytical method was successfully validated and applied to the determination of trace of As and Sb in environmental waters from diverse origin.

The growing demand for lithium-ion batteries (LIBs) has led to significant environmental and resource challenges, such as the toxicity of LIBs’ waste, which pose severe environmental and health risks, and the criticality of some of their components. Efficient recycling processes are essential to mitigate these issues, promoting the recovery of valuable materials and reducing environmental pollution. This review explores the application of electrodialysis in the process of recycling LIBs to contribute to the principles of circular hydrometallurgy. The article is structured to provide a comprehensive understanding of the topic, starting with an overview of the environmental and resource challenges associated with manufacturing LIBs. Then the current recycling processes are presented, focusing on hydrometallurgical methods. The concept of circular hydrometallurgy is introduced, emphasizing sustainable resource recovery. The electrodialysis technique is described in this context, highlighting its integration into the process of recycling LIBs to separate and recover valuable metals. Finally, the article addresses the challenges and limitations of the electrodialysis technique, such as energy consumption and system optimization, and identifies areas for future research and development. Through this analysis, the review aimed to contribute to advancing the development of more sustainable and efficient LIB recycling technologies, ensuring a safer and more environmentally friendly approach to the management of batteries’ lifecycle.

Securing the enduring sustainability of global phosphorus (P) utilization has become a key societal priority. The application of green chemistry and green engineering presents an opportunity to mitigate these challenges and contribute to the sustainable closure of the global phosphorus cycle by addressing the extraction of phosphorus from waste and subsequent reuse. In this manuscript the feasibility of a novel magnetic graphene oxide for wastewater phosphorus recovery/removal is described. The primary technical benefit of this solid adsorbent lies in its easy separation from treated water through magnetic field application. The key factors affecting the sorption efficiency (contact time, pH, and adsorbent dosage) are studied. During the first 30 min, at pH 8 and with a dosage of 0.8 g L⁻¹, 25% of the initial concentration is reduced. Among the 3 thermodynamic models proposed, the Langmuir isotherm provides the best fit to the experimental results, with a maximum adsorption capacity of 2.69 mg g⁻¹. Four kinetic models are evaluated to describe the adsorption of phosphorus on this magnetic graphene oxide for different initial adsorbate concentrations and adsorbent dosages. Among them, Langmuir kinetics provide the best fit to the experimental data. The adsorption rate constant is 0.72 L mg⁻¹ h⁻¹, and the desorption rate is 0.58 h⁻¹, in accordance with the identified Langmuir isotherm. Parameter values calculated from a mass transfer kinetic model indicate that the mass transfer of phosphorus between the bulk liquid and the solid surface is not the rate-limiting step of the adsorption process. Following the separation of this magnetic solid from the treated wastewater, an ammonia aqueous solution can recover the phosphorus from the solid adsorbent. Preliminary results show absorbed phosphorus recovery yields above 99% with a solid–liquid ratio up to 5 times higher than that used in the adsorption process.

This paper investigates the effects of a guaranteed prize incentive, in the form of an extra score, on student engagement in the quality assurance system (QAS) questionnaires employed for evaluating teaching performance at the University of Malaga. The incentive system aims to counteract declining participation rates and mitigate potential survey fatigue among students. Employing a comprehensive dataset spanning multiple academic years and subjects, the study utilized statistical analyses to evaluate the incentive’s effectiveness, considering its potential impact on both final grades and QAS questionnaire outcomes. The results demonstrate a substantial increase in participation rates, with over 85% of students acknowledging the motivating influence of the incentive. However, concerns regarding the compromise of anonymity arose among 40% of students, possibly linked to the physical presence of teachers during the verification process of the QAS questionnaire submission. The statistical analyses raise questions about the incentive’s influence on students’ final grades while indicating that the incentive system does not significantly affect the results of the QAS questionnaires. The study contributes valuable insights into the complexities of incentivizing student participation in teaching assessments within the higher education landscape. To the best of our knowledge, there are few publications that investigate the use of an additional score as an incentive for students’ participation in QAS questionnaires.

Lithium-ion batteries play an important role in our modern society as the main option to power portable electronic devices and electric vehicles. The growing demand for these batteries encourages the development of more efficient recycling processes, aiming to decrease the environmental impact of the spent batteries and recover their valuable components. In this paper, a combined hydrometallurgical-electrodialytic method is proposed for processing battery waste. In the combined technique, the amount of leaching solution is reduced as acid is generated via electrolysis. At the same time, the use of ion-exchange membranes and the possibility of electroplating allows for a selective separation of the target metals. Experiments were performed using LiCoO₂, which is one of the most used cathodes in lithium-ion batteries. First, 0.1 M HCl solution was used in batch extractions to study the kinetics of LiCoO₂ dissolution, reaching an extraction of 30% and 69% of cobalt and lithium, respectively. Secondly, hydrometallurgical extraction experiments were carried out in three-compartment electrodialytic cells, enhanced with cation-exchange membranes. Experiments yielded to a selective recovery in the catholyte of 62% of lithium and 33% of cobalt, 80% of the latter electrodeposited at the cathode.

Electrokinetic remediation (EKR) is probably the only feasible alternative to treat contaminated soils with low hydraulic conductivity. This technology is based on the application of an electric current between two groups of electrodes into the soil inducing several transport and transformation processes. As a result, the contaminants and water are transported toward the electrodes by electromigration, electroosmosis, electrophoresis, and diffusion. This study applied EKR to a real soil with a high concentration of lead. To evaluate the most suitable reagent to enhance the technique, semibatch extraction and EKR experiments at different scales were carried out. The enhancing agents used were acetic and nitric acids as weak and strong acids, respectively, and EDTA as a complexing reagent. A mathematical model for the comparison of the energy requirements at different scales was applied, showing that the defined parameter is a useful tool for the prediction of the energy requirements of EKR technique. The results indicate that the proposed methodology allows better knowledge about the behavior of contaminants under different experimental conditions.