In this age, a key target for enhancing the competitiveness of the chemical, environmental and biotechnology industries is to manufacture high-value products more efficiently and especially with significantly reduced environmental impact. Under this premise, the conversion of biomass waste to a high-value added product, biochar, is an interesting approach under the circular economy principles. Thus, the improvements in the biochar production and its new and innovative uses are hot points of interest, which are the focus of vast efforts of the scientific community. Biochar has been recognized as a material of great potential, and its use as an adsorbent is becoming a reliable strategy for the removal of pollutants of different streams, according to its high adsorption capacity and potential to eliminate recalcitrant compounds. In this review, a succinct overview of current actions developed to improve the adsorption capability of biochar, mainly of heavy metal and organic pollutants (dyes, pharmaceuticals and personal care products), is summarized and discussed, and the principal adsorption mechanisms are described. The feedstock and the production procedure are revealed as key factors that provide the appropriate physicochemical characteristics for the good performance of biochar as an adsorbent. In addition, the modification of the biochar by the different described approaches proved their feasibility and became a good strategy for the design of selective adsorbents. In the last part of this review, the novel prospects in the regeneration of the biochar are presented in order to achieve a clean technology for alleviating the water pollution challenge.

This review explores the development, technological foundations, and applications of biosensor technologies across various fields, such as medicine for disease diagnosis and monitoring, and the food industry. However, the primary focus is on their use in detecting contaminants and pathogens, as well as in environmental monitoring for water quality assessment. The review classifies different types of biosensors based on their bioreceptor and transducer, highlighting how they are specifically designed for the detection of emerging contaminants (ECs) and pathogens in water. Key innovations in this technology are critically examined, including advanced techniques such as systematic evolution of ligands by exponential enrichment (SELEX), molecularly imprinted polymers (MIPs), and self-assembled monolayers (SAMs), which enable the fabrication of sensors with improved sensitivity and selectivity. Additionally, the integration of microfluidic systems into biosensors is analyzed, demonstrating significant enhancements in performance and detection speed. Through these advancements, this work emphasizes the fundamental role of biosensors as key tools for safeguarding public health and preserving environmental integrity.

Soil pollution has become a substantial environmental problem which is amplified by overpopulation in different regions. In this review, the state of the art regarding the use of Advanced Oxidation Processes (AOPs) for soil remediation is presented. This review aims to provide an outline of recent technologies developed for the decontamination of polluted soils by using AOPs. Depending on the decontamination process, these techniques have been presented in three categories: the Fenton process, sulfate radicals process, and coupled processes. The review presents the achievements of, and includes some reflections on, the status of these emerging technologies, the mechanisms, and influential factors. At the present, more investigation and development actions are still desirable to bring them to real full-scale implementation.

In recent years, heterogeneous electro-Fenton processes have gained considerable attention as an alternative to homogeneous processes. In this context, the aim of this study is the use of a commercial iron metal-organic framework (Fe-MOF), Basolite® F-300, as a base material for the design of a heterogeneous electro-Fenton treatment system for the removal of antipyrine. Initially, the catalyst was applied as powder in aqueous solution and three key parameters of the electro-Fenton process (pH, Fe-MOF concentration and current density) were evaluated and optimized by a Central Composite Design Face Centred (CCD-FC) using antipyrine removal and energy consumption as response functions. Near complete antipyrine removal (94%) was achieved under optimal conditions: pH 3, Fe-MOF 157.78 mg/L and current density 6.67 mA/cm², obtaining an energy consumption of 0.29 W·h per mg of antipyrine removed. Later, two electrocatalysts (Fe-MOF functionalized cathodes), prepared by different Fe-MOF immobilisation approaches (composite of carbon black/polytetrafluoroethylene or by electrospinning on Ni foam), were synthesized. Their characterisation showed notable Fe-MOF incorporation into the material and favourable properties as electrocatalysts. Both Fe-MOF functionalized cathodes were evaluated in the removal of antipyrine at different pH (acidic and natural) and current density (27.78 and 55.56 mA/cm²), achieving in the best conditions removal levels around 80% in 1 h without any operational problems. In addition, several intermediates generated during the treatment were identified and their toxicity estimated. According to the obtained results, the degradation compounds have less toxicity than the parent compounds, confirming the effectiveness of the treatment.

Nowadays, the contamination of wastewater by organic persistent pollutants is a reality. These pollutants are difficult to remove from wastewater with conventional techniques; hence, it is necessary to go on the hunt for new, innovative and environmentally sustainable ones. In this context, advanced oxidation processes have attracted great attention and have developed rapidly in recent years as promising technologies. The cornerstone of advanced oxidation processes is the selection of heterogeneous catalysts. In this sense, the possibility of using metal–organic frameworks as catalysts has been opened up given their countless physical–chemical characteristics, which can overcome several disadvantages of traditional catalysts. Thus, this review provides a brief review of recent progress in the research and practical application of metal–organic frameworks to advanced oxidation processes, with a special emphasis on the potential of Fe-based metal–organic frameworks to reduce the pollutants present in wastewater or to render them harmless. To do that, the work starts with a brief overview of the different types and pathways of synthesis. Moreover, the mechanisms of the generation of radicals, as well as their action on the organic pollutants and stability, are analysed. Finally, the challenges of this technology to open up new avenues of wastewater treatment in the future are sketched out.