The tower at Lublin Castle, known as the donjon, is the only monument of Romanesque art on the eastern side of the Vistula River. The cylindrical, brick building is part of the Lublin Castle complex. During contemporary restoration work, the 13th-century walls were uncovered, making it possible to retrieve the original materials. The article presents the mineralogical, chemical and granulometric characteristics. The analytical methodology included: qualitative mineralogical analysis of the whole sample by X-ray diffraction (XRD); morphological studies with elemental evaluation and microanalysis of the binder by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). Residue determination of hydrochloric acid-insoluble parts and their granulometric analysis were performed. This methodology enabled to determine the composition of the mortars. It was found that the tested mortars have a similar mineralogical structure, but slightly differ in the proportion of individual components, primarily aggregate fractions. The samples consist mainly of quartz, calcite, and silicates. Moreover, the lime binder of the mortars was shown to be microcrystalline in nature. The aggregate used in historical mortars predominantly consisted of quartz sand and minerals of the feldspar and silicate group. The condition of the mortars requires conservation interventions. The performed characterization of the historic mortars was important for designing compatible restoration mortars.

The aim of this study was to assess the effects of two flocculants that are often used to overcome activated sludge bulking problems - aluminium chloride, AlCl3, and aluminium sulphate, Al2(SO4)3 - on Lecaneinermis (Rotifera, Monogononta) at three different temperatures: 8, 15 and 20°C. The mean EC50 value (effective concentration, mg dm-3) calculated for the 24 h mortality test was 0.012 mg Al3+dm-3. Next, the effects of low concentrations of the Al-salts on the population development from single individuals (parthenogenetic females) were tested in a 21-day experiment. At concentrations as low as EC4.8 and EC0.48, both Al-salts affected rotifer population negatively. However, temperature was the most pronounced factor that modified the toxicity of the Al-salts to the rotifers. On the 12th day of the experiment, there were significant interactions between temperature and the Al-salts, indicating that the chemicals were more toxic to the rotifers at 20°C than at lower temperatures. The weaker rotifers sensitivity to Al-salts (especially to AlCl3) in temperatures below 15°C, when the biggest problems associated with sludge bulking occurs,may means use both rotifers and chemicals reasonable and effective.