Hygienic assessment of impact on public health air pollution in view of the combined actions of chemicals in the area of the chemical industry

The article presents the results of air pollution study in the area of chemical industry. The results of evaluating possible impact of chemical pollution on the population health are reflected by the parameter values: complex indicator “R” public health risk (reflexive, chronic, and combined risk at the reflexive and chronic action), hazard index and combined action coefficient. The comparative characteristic of the received data is provided by the degree of air pollution during the evaluation, taking into account the combined effect of chemicals and during the evaluation without the combined action of chemicals. The possibility of using the results to predict the changes in the population health status and to plan epidemiological studies is determined

In situ control of thermal activation conditions by color for serpentines with a high iron content

Serpentine heat treatment at temperatures of 650–750◦C yields magnesium–silicate reagent with high chemical activity. Precise and express control of roasting conditions in laboratory kilns and industrial aggregates is needed to derive thermally activated serpentines on a large scale. Color change in serpentines with a high iron content during roasting might be used to indicate the changes in chemical activity in the technological process. This study gives a scientific basis for the express control of roasting of such serpentines by comparing the colors of the obtained material and the reference sample. Serpentines with different chemical activity were studied by X-ray diffraction, Mössbauer spectroscopy, and optical spectroscopy. The color parameters were determined using RGB (red, green, blue), CIELAB (International Commission on Illumination 1976 L*a*b), and HSB (hue, brightness, saturation) color models. The color of heat-treated samples was found to be affected by changes in the crystallochemical characteristics of iron included in the structure of the serpentine minerals. The color characteristics given by the CIELAB model were in good coherence with the acid-neutralizing ability and optical spectra of heat-treated serpentines. Thus, in contrast to the long-term analysis by these methods, the control by color palette provides an express assessment of the quality of the resulting product

In situ control of thermal activation conditions by color for serpentines with a high iron content

Serpentine heat treatment at temperatures of 650–750◦C yields magnesium–silicate reagent with high chemical activity. Precise and express control of roasting conditions in laboratory kilns and industrial aggregates is needed to derive thermally activated serpentines on a large scale. Color change in serpentines with a high iron content during roasting might be used to indicate the changes in chemical activity in the technological process. This study gives a scientific basis for the express control of roasting of such serpentines by comparing the colors of the obtained material and the reference sample. Serpentines with different chemical activity were studied by X-ray diffraction, Mössbauer spectroscopy, and optical spectroscopy. The color parameters were determined using RGB (red, green, blue), CIELAB (International Commission on Illumination 1976 L*a*b), and HSB (hue, brightness, saturation) color models. The color of heat-treated samples was found to be affected by changes in the crystallochemical characteristics of iron included in the structure of the serpentine minerals. The color characteristics given by the CIELAB model were in good coherence with the acid-neutralizing ability and optical spectra of heat-treated serpentines. Thus, in contrast to the long-term analysis by these methods, the control by color palette provides an express assessment of the quality of the resulting product. © 2021 by the authors. Licensee MDPI, Basel, Switzerland