The effect of chemical treatment of hemp hurds slices in three solutions (EDTA (Ethylenediaminetetraacetic acid), NaOH and Ca(OH)₂) on the properties of natural material was discussed in this paper. Changes in the morphology, chemical composition and structure as well as thermal stability of hemp hurds before and after their modification were investigated by using FTIR (Fourier transform infrared spectroscopy), XRD (X-ray powder diffraction analysis) and TG (thermogravimetry)/DSC (differential scanning calorimetry). Size exclusion chromatography (SEC) measurements were used for determination of degree of cellulose polymerization of hemp hurd samples. Chemical modification is related to the partial removal of non-cellulosic components of lignin, hemicellulose and pectin as well as waxes from the surface of hemp hurd slices. Another effect of the chemical treatment applied is connected with increasing the crystallinity index of cellulose determined by FTIR and XRD methods. Decrease in degree of cellulose polymerization and polydispersity index in chemically modified hemp hurds compared to the original sample was observed. Increase in thermal stability of treated hemp hurd was found. The most significant changes were observed in alkaline treated hemp hurds by NaOH.

Lightweight lignocellulosic composites are potentially contributing to sustainable development. However, lignocellulosic fillers are not always fully compatible with an inorganic matrix, which causes a variety of adverse outcomes such as the coherence and mechanical properties of composites. Therefore, experiments are made with natural fiber surface treatment. Experiments were conducted to further development of natural fibers - hemp shives of another application to lightweight composites. Untreated and chemically treated hemp shives surfaces by NaOH, Ca(OH)2 and EDTA were characterized by FTIR and TG. Changes in the FTIR spectra at 1730, 1625 and cm-1 indicated that hemicellulose and lignin from natural fiber surfaces were removed by alkaline treatment. Thermal stability of hemp shives was studied using thermal gravimetric and DSC method

Sustainability goals are essential driving principles for the development of innovative materials in the construction industry. Natural fibers represent an attractive alternative as reinforcing material due to good mechanical properties and sustainability prerequisites. The study has been focused on the comparative investigation of chemical and physical treatments of hemp hurds and their influence on the thermal behavior of main hemp constituents in air and nitrogen atmosphere. Thermal decomposition of hemp hurds involves several parallel reactions related to heat and mass transfer processes. A comparison of DSC and TG/DTG results of hemp hurds samples before and after treatments demonstrates a better thermal stability for treated samples. It is caused by changes in chemical composition due to a partial removal of non-cellulosic components from hemp hurds structure, an increase in cellulose content and decrease in its degree of polymerization. The results show different thermal behavior of the hurds samples heated under nitrogen and air atmosphere. Based on DTG records, several-stage process of mass loss has been found for the samples under air, whereas only two-stage process under nitrogen.

The construction sector contributes significantly to the production of greenhouse gases and thus to climate change. This study aims to quantify the environmental performance of selected bearing constructions with special regard to their climate change contribution and resource depletion. Environmental impacts were assessed using environmental indicators, such as global warming potential and abiotic, water and natural resource depletion. The material composition of the wall structures consisted of aerated concrete blocks, ranging from 300 to 375 mm, with different thermal-insulation materials (expanded polystyrene with graphite, and rock wool) and variable interior and exterior plaster. The evaluation was based on life cycle assessment (LCA) methodology within the ‘‘cradle to gate” boundaries. The calculated values of global warming potentials per square metre of wall construction ranged from 234.16 to 283.46 kg CO_{2 eq} for the 20-year time span, from 213.02 to 255.20 kg CO_{2 eq} for the 100-year time span and from 190.40 to 229.90 kg CO_{2 eq} for the 500-year time span. The average water consumption was identified as 3.97 m³, and the abiotic depletion was identified as 1.41 kg Sb_eq per square metre of the wall structure. The lowest environmental impact in all environmental categories evaluated was found for a structure with aerated concrete with a thickness of 300 mm with graphite polystyrene thermal insulation and with silicone outdoor plaster. Using a suitable material composition of the wall structure, up to a 20% reduction in greenhouse gas emissions can be achieved while maintaining the same thermal parameters of the structure.

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time.