The aim of the present work was to characterize the products obtained from the treatment of phosphogypsum residue by means of two recovery routes, and also to evaluate the concentrations of heavy metals and radionuclides in the materials obtained and their leachates. In this way, it is possible to determine how the most hazardous components of phosphogypsum behave during procedures until their stabilization through CO₂ fixation. This study provides an initial estimate of the possibilities of reusing the resulting products from a health and safety risk standpoint and their potential polluting capacity. The phases resulting from the transformations were controlled, and the behaviour of standard mortars manufactured from the resulting paste lime was studied. In all cases, an additional control of the leachate products was performed.

Since the Industrial Revolution, levels of CO₂ in the atmosphere have been constantly growing, producing an increase in the average global temperature. One of the options for Carbon Capture and Storage is mineral carbonation. The results of this process of fixing are the safest in the long term, but the main obstacle for mineral carbonation is the ability to do it economically in terms of both money and energy cost. The present study outlines a methodological sequence to evaluate the possibility for the carbonation of ceramic construction waste (brick, concrete, tiles) under surface conditions for a short period of time. The proposed methodology includes a pre-selection of samples using the characterization of chemical and mineralogical conditions and in situ carbonation. The second part of the methodology is the carbonation tests in samples selected at 10 and 1 bar of pressure. The relative humidity during the reaction was 20 wt %, and the reaction time ranged from 24 h to 30 days. To show the effectiveness of the proposed methodology, Ca-rich bricks were used, which are rich in silicates of calcium or magnesium. The results of this study showed that calcite formation is associated with the partial destruction of Ca silicates, and that carbonation was proportional to reaction time. The calculated capture efficiency was proportional to the reaction time, whereas carbonation did not seem to significantly depend on particle size in the studied conditions. The studies obtained at a low pressure for the total sample were very similar to those obtained for finer fractions at 10 bars. Presented results highlight the utility of the proposed methodology.

This study examines the perceived productivity of office occupants in moderate thermal environments in Chile. Specifically, it analyses environmental parameters and contrasts participants’ self-reported answers to cross-sectional and retrospective questionnaires. To this end, data were collected for one day in winter and one day in summer, in eighteen office buildings in the cities of Concepción and Santiago. The results show that the average operative temperatures are 22.2 °C in winter and 23.5 °C in summer. 80.5% of the occupants declared their productivity to be normal on the cross-sectional survey. However, on the retrospective survey, 82.7% said that their productivity is affected by the thermal environment. To reveal the interrelationships between perceived productivity and the thermal environment, a categorical principal components analysis was carried out. It demonstrated that there is only a relationship between cross-sectional and retrospective productivity in winter. Subsequently, a good-fitting structural equation model was created, which showed that different relationships exist between the variables. These findings could enable organizations and design professionals to better understand occupants’ perceived productivity in relation to thermal conditions in office buildings.