Diatoms are very diverse and highly productive organisms, found in a wide variety of environments. This study aims to analyze the growth and lipid composition of Phaeodactylum tricornutum, cultured in an outdoor pilot-scale bubble column photobioreactor under natural conditions in Chile for biodiesel production. Results showed that P. tricornutum cultures reached their highest biomass concentration (0.96 ± 0.04 kg m⁻³) after 14 days of culturing, at the stationary phase, with a volumetric productivity of 0.13 kg m⁻³ d⁻¹. Biomass samples showed a total lipid content of 9.08 ± 0.38 wt %. The fatty acid methyl ester analysis revealed a composition of 24.39% C16-C18 fatty acids, 42.34% saturated fatty acids, 21.91% monounsaturated fatty acids and 31.41% polyunsaturated fatty acids. These findings suggest that P. tricornutum oil can be used as an alternative raw material for the production of biodiesel capable of meeting international quality standards.

The expansion of photovoltaic solar energy in the world is significant. However, its contribution to decreases in greenhouse gases (GHG) is not an absolute guarantee. In this context, it is necessary to evaluate its benefits in advance, considering the structure of the electric energy supply matrix of the country producing the photovoltaic solar system, as well as the country where the technology will be implemented. This study evaluates the adoption of renewable sources for electric power generation in a country with a high share of renewable energy. A life-cycle assessment (LCA) of a set of multi-Si photovoltaic (PV) systems installed in the Brazilian northeast (NE), was carried out. The actual generation data of 10 plants totaling 1.1 MWp installed capacity were evaluated during two years of operation. Energy payback time (EPBT), greenhouse gas emission rate (GHGe-rate), and emission payback time were calculated. The great influence of the electric matrix characteristics of the country manufacturing PV systems was evidenced in the results. The interconnected Brazilian electrical system had a 2020 projected GHGe-rate of 63.9 g CO₂/kWh, while the results of 70% of the photovoltaic solar power plants (PSPS) assessed herein exhibit higher GHGe-rates. Thus, in countries where the electric matrix comprises a high share of renewable sources, such as Brazil, the incentive to use PV systems manufactured in nations whose electric matrix registers high emission factors should be well evaluated in terms of the impacts of GHG concentrations and the promotion of sustainable development, in order to avoid indirect import of significant amounts of carbon embedded in the systems.

Semi-arid regions have historically suffered from low water availability. In addition, the increasing frequency and intensity of extreme weather events credited to global climate change has made it increasingly clear that among the challenges faced by society water resource management is extremely necessary. In this context, desalination based on renewable energy resources integrated with production systems that make use of the waste resulting from this process becomes a socio-environmentally indicated alternative to expand existing supply strategies and sustainable water use in isolated locations, and/or areas distant from large urban centers, thus addressing local potential and reducing environmental impacts. This study assesses the use of Photovoltaic Solar Power Plants (PSPPs), as well as of residues generated in a Brackish Water Reverse Osmosis System (BWRO), in productive units linked to fish and family farming. This is as an alternative way to reduce water vulnerability in the Brazilian semi-arid area (BS), adhering to climate change adaptation measures in the light of Brazilian public policies through the Freshwater Program (Programa Água Doce—PAD), which aims to promote access to good quality water to approximately 500 thousand people in the Brazilian semi-arid region.

The relationship between natural elements and developed areas of the Rio de Janeiro landscape is the main reason for its national and international visibility, a major incentive for the creation of an urban planning models that focus on environmental preservation and sustainable development. The current article presents a proposal for implementing the Ecological-Economic Zoning as a tool for planning and managing the municipality through an integrated perspective. Guidelines for land use and occupation are defined in a participative manner, encompassing and integrating the ecological, economic and social dimensions of urban sustainable development.