Heavy metals polluting the natural environment are absorbed by plants. The use of herbs as components of cosmetics may pose a health risk for humans. The aim of the study was to determine the concentrations of Pb, Cd and Hg in selected species of herbs (horsetail Equisetum arvense, nettle Urtica dioica, St. John’s wort Hypericum perforatum, wormwood Artemisia absinthium, yarrow Achillea millefolium, cottonwood Solidago virgaurea) self-collected from the natural environment in two different locations, and purchased in stores on the territory of Poland. The concentration of the metals studied was: 4.67–23.8 mg/kg Pb, 0.01–1.51 mg/kg Cd, 0.005–0.028 mg/kg Hg. Different concentrations of metals, depending on species and origin of plants, were found. The mean concentration of all studied metals was the lowest in St. John’s wort, and the highest in nettle. In herbs purchased in Polish stores, the concentration of Pb was higher than in plants self-collected in the natural environment.

Geopolymers can be treated as an environmentally friendly alternative for concrete and enables utilization of various wastes. This paper focuses on the possibility of application of discarded cathode ray tube (CRT) glass inside a metakaolin-based geopolymer in the form of an aggregate, providing an ecological method of recycling of this hazardous material. The main goal of this paper was to develop an optimal composition of a new geopolymer and to describe its behavior under varying curing conditions. A geopolymer made of different mixtures was subjected to flexural and compressive strength tests. The density, mass loss, temperature changes, and metals leaching were determined as well. The results demonstrated that neither the content of CRT glass nor the curing regime has a significant influence on the mechanical behavior. However, the strength of the geopolymer containing 50% CRT glass by mass increased with time in contrast to a geopolymer with a higher CRT glass content. The development of temperature inside the mixture was dependent on the amount of metakaolin. The concentration of toxic metals in an aqueous extract decreased considerably after the encapsulation of CRT glass inside the geopolymer. The presented results indicate that discarded CRT glass can be considered an aggregate for a metakaolin-based geopolymer. The new material shows high strength and makes the CRT glass safe for the environment.

Simple physical characterization of water evaporation can provide detailed information regarding its component distribution in particulate matter (PM) samples. The water presence in PM can greatly influence its polarity and subsequent reaction activity, for example, in secondary inorganic and organic matter formation. In this study, the presence of PM-bound water is detected using the Karl Fischer titration method in a temperature gradient with an aim to quantitatively assess different types of water occurrence. The analyses were initiated by testing two reference materials, namely urban particulate matter 1648a and urban dust 1649b (NIST). Four different types of water were found in both NIST materials, which helped to optimize the temperature ramp program and its adjustment for real PM samples. It was found that water contents in total suspended particles (TSP) are similar to those typically occurring in urban background stations—approximately 7.12–45.13% of the TSP mass, differentiated into the following water mass contributions: 48.5% of the total water found was loosely bound water; 23.3% was attributed to the absorption water; while the missing 20% could be probably attributed to crystal water removed only above 180 °C and artifacts connected with the drift correction problem. By comparing water release curves for single PM-compounds like pure SiO₂; Al₂O₃; NH₄NO₃; (NH₄)₂SO₄ and NH₄Cl with water spectra obtained for real PM samples, it was found that water in particulate matter mainly comes from the dehydration of TSP-bound crystalline like Al₂O₃, SiO₂ and to a lesser extent from salts like NH₄NO₃; (NH₄)₂SO₄ and NH₄Cl. A newly used thermal ramp method was able to assess water contents from Teflon–polypropylene baked filters characterized by low melting points and therefore filter degradation even under temperatures oscillating around 200 °C. The advantage of this new work is the separation of different types of TSP-bound water contributions, facilitating and promoting further research on the origin of PM-bound water and its role in atmospheric chemistry, secondary aerosol formation and visibility.

In accordance with the Circular Economy, the metallurgical solid wastes are considered secondary resources of many heavy metals, such as lead, zinc, iron, cadmium, thallium, and others. To separate valuable and toxic metals, numerous processes, among them solid–liquid extraction, have been studied in recent years. In line with this trend, the objective of this study was to investigate the possibility of leaching selected heavy metals (Pb, Zn, Cu, and Fe) from slag generated by the zinc and lead metallurgical industry. The effect of the leaching agent type (HCl, NaOH, and Na₂NTA) and concentration, pH, solid-to-liquid (S/L) ratio, and interphase contact time on process efficiency was evaluated experimentally. The slag was comprehensively characterized using atomic absorption spectrometry (AAS), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), and BCR (Community Bureau of Reference) sequential extraction to determine the total metal concentration, element and phase composition, as well as chemical speciation of the investigated metals. To determine the kinetic mechanisms the Weber–Morris and shrinking-core models were used. The efficiency of metal separation from slag strongly depended on the process parameters. HCl was highly effective for simultaneous metal leaching, particularly Pb, Zn, and Cu (up to over 80%), while NaOH and Na₂NTA allowed for the selective separation of Pb with leaching efficiencies of up to 80% and 90%, respectively. Sequential BCR analysis confirmed the different forms of metal occurrence, with predominating highly mobile Pb fractions and stable, residual Cu and Fe fractions. Comparative analyses using SEM and sequential BCR extraction revealed significant changes in slag morphology and metal speciation following leaching with the HCl solution. The Weber and Morris model indicated the kinetic contribution of the intraparticle diffusion within the slag’s porous structure, especially under HCl-based leaching. An analysis using shrinking-core models revealed different predominant mechanisms for specific metal–leaching agent systems.

Gravimetric quantification of atmospheric particulate matter (PM) is biased by particle-bound water that persists after routine filter conditioning, with the magnitude depending on chemical composition, mixing state, and the operational definition of "water" inherent to the analytical protocol. Here, particle-bound water was quantified by Karl Fischer (KF) coulometric titration combined with stepwise heating to differentiate weakly adsorbed from more strongly retained fractions. Thirty-five single-component chemicals and certified reference materials (CRMs) were analyzed at two mass loadings (0.6 and 2.0 mg), corresponding to typical summer and winter filter loads, together with artificial PM (aPM) mixtures examined as sequential-addition systems and as bulk samples of atmospherically relevant composition. Bulk KF measurements revealed marked class-dependent differences: deliquescent inorganic salts retained the largest water masses, whereas most metals, metal oxides, polycyclic aromatic hydrocarbons, and graphitic carbons approached analytical background. Water-to-solute molar ratios (W/S) enabled cross-compound comparison and demonstrated non-linear scaling with loading—absolute water generally increased with mass, but W/S decreased, consistent with reduced vapor accessibility in compacted powders. Principal component analysis of replicate-averaged W/S values confirmed that water retention is chemically stratified and predominantly one-dimensional, with PC1 explaining 98.5% of variance (intrinsic hygroscopicity) and PC2 (1.5%) capturing minor mass-dependent effects. Sequential aPM experiments showed that secondary inorganic species dominate retained-water contributions, and bulk aPM thermal release profiles closely matched those of ambient PM₁ filters. PM-bound water is best described as a continuum of binding states governed primarily by composition and modulated by loading, informing approaches to mitigate humidity-related bias in gravimetric PM determination.