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A new composite material, named TSC/AXAD-2, was developed by incorporating a bis-thiosemicarbazone derivative (TSC) into Amberlite XAD-2 to extract Pb2+ ions from wastewater. The new composite was characterized using XPS, TGA, FTIR, BET, EDX, 1H-NMR, 13C-NMR, and GC-MS analyses. The sorption parameters, such as pH value of media, equilibrium time, initial Pb2+ ion concentration, composite dose, temperature, and eluting agents, were methodically optimized. The utmost adsorption capacity is 45.3 mg.g−1; it was achieved at pH value of of 5.5, 15 min of agitation, room temperature, and initial concentration of 200 mg.L−1 Pb2+ ions. The isotherm studies revealed that the adsorption process closely matches the Langmuir model, with a theoretical retention capacity of 46.12 mg.g−1. Furthermore, kinetic modeling using the pseudo-first-order accurately depicted the adsorption of Pb2+ ions. The thermodynamic study suggested that the adsorption process is exothermic, spontaneous, and more favorable at lower temperatures. The desorption of Pb2+ ions from the loaded composite was conducted with 1.0 M of either HCl or HNO3. The TSC/AXAD-2 composite successfully met WHO and FAO guidelines for removal of Pb2+ ions from wastewater before its discharge into the marine environment. [ABSTRACT FROM AUTHOR]

Radon is a radioactive noble gas omnipresent in the environment, being part of the 238U and 232Th decay chains present in the Earth's crust. The gas can easily leak through the ground but also be present in natural construction materials and migrate into indoor places where it can be a carcinogen when inhaled. Studying the content and removal of indoor radon is crucial for the evaluation and mitigation of its radiological risks to public health. For more than 100 years, the removal by adsorption of the radon has been performed on activated charcoal. There is little progress in the field of radon adsorption at ambient conditions; the main progress is in the use of zeolite materials, having well-defined three-dimensional porous structures and radiation resistance. This study concerns a report on the state of the art of the application of zeolites in radon adsorption. Furthermore, an optimized approach for measuring the radon content in indoor environments and, consequently, its removal has been proposed. Adsorption systems based on zeolites have the potential to replace activated charcoal as a material of choice, allowing to facilitate the development of simple and compact radon adsorption systems. [ABSTRACT FROM AUTHOR]

Urban soil and urban surface deposited sediments (USDS) are a large basin for receiving heavy metal contaminants from natural resources and anthropogenic activities. The present study is a review carried out the previous studies determine metal impacts in the urban environment on potential health hazards. The environmental risk index (Er) values follow a trend for different urban soils and USDS: the high Er value in the period 1980–1990 in urban areas is due to Cd 7200, followed by Pb 662, Cu 42, Zn 23, and Ni 6. The health risk assessment varied with the type of heavy metal, the time of year, the level of contamination, environmental pollution, and the human age. No significant risk was identified for adults and children in different urban areas. [ABSTRACT FROM AUTHOR]