Eutrophication, driven by nutrient enrichment, poses a global challenge, impacting the ecosystem, water supply systems, and ultimately, human health. In this research, water unavailability due to phosphorus pollution was assessed in Brazilian semiarid reservoirs with data measured over a decade. Management strategies to control eutrophication were simulated using physical-mathematical modeling of the phosphorus budget in the water and sediment layers. The model parameters were calibrated from 1976 to 2021, and the results were validated by comparing measured and modeled duration curves of phosphorus concentration. Water unavailability due to phosphorus pollution occurred approximately 61% of the time, indicating the need for effective control strategies. Simulation of sediment removal when the reservoirs dry up showed potential to contribute to water quality in reservoirs with high emptying frequency, while external phosphorus load reduction proved to be more widely efficient. The variation in the effectiveness of the techniques among the studied reservoirs emphasizes the need for approaches adapted to the specific conditions. This work contributes to improve the understanding of phosphorus dynamics in reservoirs with high water level fluctuations and appropriate management measures to control eutrophication in dry environments.
The building materials industry encounters naturally occurring radioactive materials problems and elicits growing attention in radiation protection regulations. However, the availability of useful, comprehensive data on radiological hazard in building materials is unfortunately scant: data are few and far between. In the Italian region of Emilia-Romagna, there is a flourishing ceramic industry, with a vast production of building materials, particularly tiles and bricks. Our laboratory of Environmental Chemistry and Radioactivity has collaborated with this industry since the year 2000, collecting over time a vast number of samples and processing them through high-resolution gamma spectrometry, to obtain a large dataset of radionuclide contents. This paper presents a radiation protection study based on said dataset, aimed at assessing the radiological risk associated with these materials: in particular, different indexes, internationally accepted, and dose rates are calculated in compliance with well-established EU algorithms. Statistical treatment of data is also presented.
The studied region is located in the southwestern Iran and on the border of Iran and Iraq. In the past, this region had dense palm groves and abundant plants. However, due to the decrease in upstream discharge, in recent years, saline and sodium seawater has intrusion in the river and affected the agricultural lands along its sides. This event has caused irreparable and serious damage to the agricultural industry in the region, turning this area into a graveyard of date palm trees. Understanding the characteristics of agricultural soils for their improvement and/or planting appropriate plants is one of the goals of sustainable agriculture. Considering the damage of the studied area from the intrusion of salt water in the Arvand River, this study investigated important characteristics of soil salinity including EC, pH, C.E.C, SAR and ESP. In this research, sampling of agricultural soils along the riverside was carried out in three different horizons and two line parallel to the river and at two different distances. Statistical methods of correlation coefficient, hierarchical analysis and factor analysis were used to identify the factors affecting soil quality and the relationships between parameters. The results showed that due to the intrusion of sodium seawater, the soils of the studied area have become saline-sodium, and the salinity level in the soils near the river mouth is higher than that in the soils on the upstream side of the river. In terms of fertility, the cation exchange capacity is in the medium range, and the clay texture and abundant organic matter of the soil as a result of the remaining plant and tree residues have an important effect on this parameter.
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