Biochar is a carbonaceous material, which can be decorated with metals, that has been garnering attention to be used in the treatment of water due to its contribution to waste management and circular economy. This study presents the life cycle assessment (LCA) regarding the generation of Pinus patula raw biochar and its modification with iron (Fe-modified biochar). SimaPro 9.3.0.3 software was used to simulate the environmental impacts of both carbonaceous materials. The potential environmental effects obtained from the production of Pinus patula raw biochar were mainly ascribed to the source of energy utilized during this process. The potential impacts demonstrated that the generation of gases and polycyclic aromatic hydrocarbons are the main concern. In the case of Fe-modified biochar, the potential environmental effects differed only in the stage of the biomass modification with the metal. These effects are associated with the extraction of Fe and the generation of wastewater. These findings provide an insight into the environmental effects linked to the production of raw and Fe-modified biochar. However, further LCA research should be performed concerning other materials and compounds than can be generated during the biomass thermochemical conversion.

When dyes are discharged in water bodies, mutagenic, carcinogenic and teratogenic effects may be caused in both aquatic organisms and human beings. The use of biochar and the implementation of advanced oxidation processes (AOPs) are alternative treatments that have been used individually in the removal of dyes in wastewater. Besides being effective processes acting separately, biochar and AOPs can be coupled, exhibiting synergetic effects in the treatment of dyes contained in water. This work deals with the methods implemented to produce biochar from biomass, its mechanism in the removal of dyes and associated sustainability issues. Additionally, the main AOPs that have been utilized for the removal of dyes from water are covered, as well as the biochar-AOP combined processes. The future prospects for the removal of dyes from water have been also addressed. The coupling of biochar to AOPs has been proven to be more effective in the removal and mineralization of dyes than the individual treatments. In this regard and considering the scarce studies in the field, new horizons are opened on the treatment of water polluted with dyes.

The presence of pharmaceuticals in aquatic ecosystems is an issue of increasing concern. Regardless of the low concentration of pharmaceuticals in water, they can have a toxic effect on both humans and aquatic organisms. Advanced oxidation processes (AOPs) have been described as a promising technique for eliminating pharmaceuticals due to their high efficiency. However, the cost associated with the application of these processes and their high reagents and energy requirements have affected the implementation of AOPs at large scales. Biochar has been suggested to be used as a catalyst in AOPs to overcome these limitations. Biochar is considered as an alternative heterogeneous catalyst thanks to its physicochemical characteristics like its specific surface area, porous structure, oxygen-containing functional groups, electrical conductivity, persistent free radicals (PFRs), modifiable properties, and structure defects. This carbonaceous material presents the capacity to activate oxidizing agents leading to the formation of radical species, which are needed to degrade pharmaceuticals. Additionally, AOP/biochar systems can destroy pharmaceutical molecules following a non-radical pathway. To enhance biochar catalytic performance, modifications have been suggested such as iron (Fe) impregnation, heteroatom doping, and supporting semiconductors on the biochar surface. Although biochar has been efficiently used in combination with several AOPs for the mineralization of pharmaceuticals from water, further research must be conducted to evaluate different regeneration techniques to increase biochar’s sustainable applicability and reduce the operational cost of the combined process. Moreover, operational conditions influencing the combined system are required to be evaluated to discern their effect and find conditions that maximize the degradation of pharmaceuticals by AOP/biochar systems.

The feasibility of an adsorbent material like biochar (BC) depends on its regeneration capacity and its ability to achieve high removal efficiencies on real wastewater (WW) effluents. In this study, the regeneration capacity of the Pinus patula BC previously used in the removal of Indigo Carmine from water was evaluated. The regeneration technique that resulted in the highest desorption efficiency was a thermo-chemical method that consisted of heating the spent BC in a stove at 160 °C for 45 min followed by regeneration with ethanol (C₂H₆O) at a concentration of 75% for 6 h. Through this regeneration method, it was found that Pinus patula BC could be used in seven consecutive adsorption–desorption cycles. The feasibility of this BC was also assessed by evaluating the adsorbent’s efficiency in real textile WW. Under optimal operational conditions (solution pH = 3, BC dose = 13.5 g/L, and BC particle size = 300–450 µm), the highest removal efficiencies in terms of colour and dissolved organic carbon (DOC) were 81.3 and 76.8%, respectively, for 120 min of treatment. The results obtained in the regeneration studies and the treatment of real textile WW suggested that the use of Pinus patula BC could be suitable to be scaled to an industrial level, contributing to sustainable development and the circular bioeconomy by using a waste to solve the dye pollution problem of another waste.

The increasing global demand for renewable energy sources for electricity generation, coupled with the urgent need to reduce reliance on fossil fuels, has made the transition to cleaner alternatives more critical in recent years due to the environmental degradation caused by fossil fuel consumption. Among renewable energy sources, wave energy stands out as one of the most promising options because its resource, ocean waves, is inexhaustible. To harness wave energy, one effective device is the oscillating water column (OWC), which converts the kinetic energy of waves into electrical power. Despite the significant capacity of wave energy, particularly through the implementation of OWCs, the environmental and socio-economic impacts remain insufficiently studied. This research addresses this gap by analyzing the potential impacts associated with the deployment of wave energy systems, such as OWCs. Specifically, a sustainability assessment of OWCs was conducted, and a cause-and-effect matrix was developed using Conesa’s methodology to evaluate the impacts linked to their design, installation, operation, maintenance, and disassembly phases. The results obtained revealed that the majority of impacts caused by an OWC are moderate. Notably, the most significant positive effects are related to improvements in the quality of life of communities benefiting from the technology studied. The findings underscore the sustainability of OWCs in harnessing wave energy to generate electricity.

Los colorantes son un grupo de contaminantes de creciente preocupación debido a la toxicidad asociada a su presencia en el ambiente y a su carácter recalcitrante al momento de ser degradados por medio de procesos convencionales con los que operan las plantas de tratamientos de aguas residuales. En este sentido, el biocarbón, considerado como un sub-producto derivado del proceso de conversión termoquímica de la biomasa, se posiciona como un tratamiento alternativo gracias a sus propiedades fisicoquímicas, como lo son su gran superficie específica y grupos funcionales. En este trabajo, se presenta el concepto, clasificación y propiedades de los colorantes, así como los efectos adversos que causan estos contaminantes en los ecosistemas acuáticos. Adicionalmente, se exponen los tratamientos usados en la remoción de colorantes del agua residual, haciendo énfasis en el uso del biocarbón como tecnología alternativa. Finalmente, se presenta la relación costo-eficiencia del biocarbón, teniendo en cuenta su capacidad de reusabilidad. Con este trabajo, se abren nuevos horizontes en el uso del biocarbón para el tratamiento de aguas contaminadas, contribuyendo a la economía circular y al tan anhelado desarrollo sostenible.