Development must balance social, economic, and environmental sustainability; it is for this reason that the Sustainable Development Goals (SDGs) are integrated, in fact, action in one of them will affect outcomes in others. In consequence, research on the SDGs is broad, complex, and fragmented due to the great diversity of disciplines and approaches involved, making it difficult to obtain valuable and unbiased information for future studies. As a result, a comprehensive review of contributions could provide a comprehensive critical perspective. This article applies SciMAT software to analyze the evolution of this field of research through a systematic literature review of bibliographic records on the SDGs and a review based on bibliometric analysis of 10,272 selected records. Additionally, hidden themes and their development in this field from 1990 to 2020 have been identified to produce strategic diagrams, graphs of thematic evolution and performance indicators of the research field in different periods. The results obtained show a constantly evolving scientific field, from its initial focus on the millennium goals to the gradual inclusion of the current SDGs. They provide field experts with a comprehensive overview of the status quo and predict the dynamic directions of future research, serving as a basis for the development of new strategies for the implementation of the SDGs.

Energy recovery, according to circular economy and sustainable principles, has established itself as an inevitable field of action in wastewater treatment plants (WWTPs). Energy costs are forcing the optimization of processes and increases in the development of applicable waste-to-energy (WtE) technologies. This study aims to analyze the existing knowledge on WtE research in municipal WWTPs using a systematic literature review and a bibliometric analysis from 1979 to 2021. For this purpose, Science Mapping Analysis Tool (SciMAT) and VosViewer, two softwares for analyzing performance indicators and visualizing scientific maps, were used to identify the most relevant figures in the research. The results show an exponential increase in the number of publications over time, which has yet to reach a stage of maturity. The analysis of the evolution of the topics exposes variability in the keywords over the years. The main field of WtE research has focused on sludge treatment, with technologies ranging from anaerobic digestion to more recently-emerging ones such as microalgae or membrane technologies. The analysis also identified the need for more publications on other wastes in WWTPs, which are necessary to achieve zero waste.

One of the main sectors responsible for the acceleration of climate change and the depletion of natural resources is the construction industry. This industry is responsible for using 40-50% of the Earth's energy and increasing the anthropogenic emissions of greenhouse gases. In this context, it is essential to study regional climates in order to foresee the adverse effects of construction and take the appropriate measures to avoid or minimise the damage that can be caused in the medium and long term. The balance between the climatic zones assigned to a region and the construction that be carried out there is fundamental. The proposed guidelines to obtain a potential classification could serve as a starting point for the bioclimatic design of buildings. To combat the heat island effect through building, it is considered viable to develop bioclimatic charts in the main cities of Spain to identify the possibilities of urban microclimates and to be able to combine these results with those obtained by climate severities. In order to adapt the climate classifications to the H2100, the proposal is to apply this methodology with the prediction data indicated by the Intergovernmental Panel on Climate Change, having, as a goal, the development of zoning that adapts to the climatic conditions.

Using a science mapping approach, we analyzed the exponential increase in the number of scientific documents about the negative environmental impacts produced by waste from personal protective equipment (PPE), especially face masks, used to reduce SARS-CoV-2 transmission worldwide. Our results revealed that India, China, and Canada are leaders in this research field, which is clearly related to environmental issues, but also the solutions developed from an engineering point of view. Our analysis of the most-relevant documents in the field uncovered the considerable negative effects of PPE waste in aquatic media, its contribution to greenhouse gas emissions, effects on wildlife, etc. To reduce the negative environmental impacts of PPE waste, we need to implement innovative ecodesign strategies for their green production, including their re-use as and the use of recycling materials, but also a collaboration with the population to reduce PPE waste at its source. Both action lines could be materialized by establishing a collective, extended producer responsibility system for PPE to ensure their sustainable production and consumption. These well-implemented strategies will contribute to maintaining progress towards achieving sustainable development goals.