Plant-based systems for the treatment of contaminated environments (phytoremediation) have been proved to be highly efficient in removing pollutants, especially heavy metals. However, in strictly aquatic and high-flow treatment systems, the use of free floating plants could be more adequate. For a treatment system based on phytoremediation strategies to be feasible and sustainable, it is essential that the plants used are not only efficient in pollutants removal, but also abundant in the region, easily accessible, and do not require special culture conditions. In this work, we evaluate the capacity of four different autochthonous macrophytes obtained from the Paraná river (Argentina) to adapt and reproduce without any additional nutrient supply or temperature special conditions (laboratory «indoor» environment). Only those specimens that doubled their biomass in a two-week period without any visual signs of deterioration (loss of turgor, chlorosis and/or necrosis of leaves) were considered for further analysis. From different pre-selected species, only Salvinia biloba Raddi showed a wide capacity to adapt and reproduce under these conditions. Moreover, the ability to remove lead (Pb 2+) by S. bilobawas evaluated in water samples contaminated with three metal concentrations (4.8 ± 0.3, 9.1 ± 0.4 and 19.6 ± 0.5 mg/L) at different exposure times (0-24 h), showing a high efficiency in the pollutant elimination. A compartmentalization analysis indicates that surface adsorption was the predominant mechanism for Pb 2+ removal at the first 24 h. Finally, the bioconcentration factor (BCF) was calculated at the end of the exposure time,reflecting both hyperaccumulation capacity and high metal tolerance by this plant. Our results suggest that incorporation of S. biloba in wastewater treatment systems could be a successful strategy to efficiently remove heavy metals by bioremediation processes.

a b s t r a c tRising temperatures, increasing food demand and scarcity of water and land resources highlight the importance of promoting the sustainable expansion of agriculture to our urban environment, while preserving water resources. Treating urban wastewaters, such as greywater and hydroponic wastewater, may represent a strategic point for the implementation of urban farming, ensuring food security, reducing pressures on water resources and promoting climate change mitigation. The WETWALL design concept proposes a unique ecotechnology for secondary wastewater treatment at an urban scale, which brings the novelty of a modular living wall hybrid flow. This concept is based on the integration of two established nature-based solutions/ecomimetic designs: constructed wetlands and a modular living walls. First presented is an overview about the state of the art in the scope of living walls treating wastewater, in order to identify the main design aspects related to the performance of such systems, which mainly concerns the removal of nitrates and phosphates. Second, the WETWALL design concept is presented. A scheme regarding the selection of the main components, such as plants and substrate, is proposed, and potential structure developments and operation strategies are discussed. In addition, considering the scope of integrating the circular economy with the design process, potential interactions between this technology and the urban environment are discussed. The main goal of this article is to substantiate the potential of the WETWALL design concept as an innovative wastewater treatment at an urban scale.

Greenhouse gases emissions resulting from the combustion of fossil fuels are worsening air quality and affecting the climate system. While climate change impacts on meteorological variables affects air quality by altering the concentration and distribution of pollutants, air pollution significantly influences the climate, leading to negative impacts on human health. Due to the combination of high temperatures, air pollution, and high population density, cities are particularly vulnerable to climate change impacts. The planning and design of public spaces aimed at climate change mitigation and adaptation can result in multiple co-benefits for human health, while reducing social inequalities. To address the major research gaps in the communication between health and planning experts, and the lack of capacity among public sectors and policy makers, it is necessary to promote capacity building and knowledge sharing between the planning and health sectors. The purpose of this article is to develop preliminary recommendations for a process that allows a comprehensive assessment of the interlinkages between climate and health, social, environmental, and economic vulnerabilities, and the quality of the urban spaces, to support local governments, policymakers, and education institutions in making informed decisions for public spaces. The methods applied were a literature review and interviews with experts.

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