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As the global population becomes more concentrated in urban environments, higher numbers of people will be exposed to urban air pollution. The environmental and human health benefits of green roofs are widely recognized. The aim of this paper is to promote green roofs as an effective passive technique for pollution mitigation and adaptation to climate change. During the heating season, the ambient concentrations of PM1, PM2.5, and PM10 were measured above a green roof and a reference roof on a school building, located in New Belgrade, the second-most populous municipality and business center of Serbia’s largest city. The percent reduction of PM10, PM2.5 and PM1, in January 2020, above the green roof compared to the reference roof was 7%, 16.6%, and 17.6%, respectively. The results show that lightweight green roof improve air quality in terms of PM concentrations for all months considered. In this paper, correlation analysis and the use of Pearson’s coefficient were used in the process of analysis to determine the relationship between PM10, PM2.5, PM1, and ambient parameters: relative humidity, ambient temperature, and wind speed. It was found that the statistical correlation expressed by the Pearson coefficient between all PM particles and wind speed was statistically significant in all observed months except September. Also, the degree of significance of the correlation between PM particles and humidity and temperature of ambient air varies by month.

Green roof systems have become an important part in creating sustainable cities. They can provide a wide range of economic, environmental, and social benefits. The goal of this research was to quantify the thermal performance improvements from a green roof with mineral wool substrate installed on a school building in a humid subtropical climate. In-situ measurements during a summer period included heat fluxes through the green and reference roof, vertical temperature profile through both roofs, the local air temperature above roofs, and local meteorological parameters. Furthermore, the summer thermal performance of green and reference roof and the green roof cooling effect were evaluated concerning meteorological parameters using the Pearson correlation analysis. The results indicate that the green roof layers have improved thermal performance of the roof with respect to reduced conductive heat flow by 57% and delayed heat transfer. The maximum and averaged reference roof to green roof outdoor surface temperature difference was 27.5 degrees C and 5.5 degrees C, respectively. It was found that ambient temperature and relative humidity have a dominant role on the thermal performance of the green and reference roof, while solar radiation and ambient temperature present the key meteorological determinants of the green roof cooling effect.

The Republic of Serbia has a significant potential for the electricity production from solar energy, namely the floating photovoltaic (PV) systems, which are not exploited enough. Although there is a large interest in floating photovoltaic systems (FPVS) worldwide, studies related to the assessment of FPVS potential in this part of Europe have not been performed yet. This paper investigates, for the first time, the possibility of implementation of the FPVS on the six largest Serbian lakes and demonstrates the impact of geographical location on the energy output of the FPVS for the selected locations. The possibility of implementation is studied by simulating the energy output of FPVS using "PVGIS" tool. Energy production from the proposed FPVS, for selected locations, is discussed on a monthly and yearly basis. Installment of the FPVS on these water bodies can produce up to 8959 kWh of energy, while saves 164⋅10^6 m3/year of water from evaporation at the same time. In addition, the annual reduction of carbon dioxide emissions was analyzed and found to be up to 6.34 tons per year, which further implies with carbon credit potential of up to 9741 € in 20 years period. Drawn conclusions provides better understanding of FPVS and their applicability in the Republic of Serbia to ensure a sustainable, ecological friendly, secure and reliable supply of green energy, and further the used approach can be easily applied in other countries with similar geographical characteristics.