Nowadays, the material recycling is a growing trend in development of building materials and therefore using of secondary raw materials for production new building materials is in accordance with sustainable development in civil engineering. Therefore, it is increasingly becoming crucial to accelerate the transition from application of non-renewable sources of raw materials to renewable raw materials. One fast renewable resource is natural plant fibers. The use of the cellulosic fibers as environmentally friendly material in building products contributes to the environmental protection and saves non-renewable resources of raw materials. Wood fibers and recycled cellulose fibers of waste paper appear as suited reinforcing elements for cement-based materials. In this paper, there is used application of Fourier transform infrared spectroscopy (FTIR) on cellulose fibers coming from different sources. FTIR spectra of cellulose fiber samples are investigated and compared with reference sample of cellulose.
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.
Sediments are normally the final pathway of both natural and anthropogenic components produced or derived from the environment. Sediment quality is a good indicator of pollution in the water column, where heavy metals and other organic pollutants tend to concentrate. Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. Heavy metal concentration in the water column can be relatively low in some cases, but the concentrations in the sediment may be elevated. The presented work aimed to investigate the pollutant levels of some heavy metals (Fe, Mn, Al, Cu, Zn, As, Cd, Pb) in the water and sediments related to acid mine drainage (AMD) produced from an abandoned sulphide mine in Smolnik in Eastern Slovakia. A metal pollution index was used to compare the total content of metals at five sampling stations. The level of partitioning of the metals between the surface water and sediments in the area was calculated using Partition coefficients and the correlation coefficients between the metal pairs in both media were calculated by a Pearson coefficient.
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