Chemical precipitation is a useful conventional process to remove heavy metals from aqueous solutions. In this work, a waste sludge from the Solway process was used as a precipitation agent for the precipitation of Cu (II), Ni (II), Pb (II) and Zn (II) ions with an initial concentration of 50 mg/L. The results of the research showed that the waste sludge from the Solway process completely removed Pb (II) ions from the solution in the pH range of 8.39 -11.74, also good efficiency was shown in other cations. The maximum precipitation efficiency for Cu (II) is 99.890% at pH 10.98, Ni (II) 99.940% at pH 11.81, Zn (II) 99.616% at 10.1. Waste sludge is proved to be a good precipitate for cation separation.

Muesli bars is a generic term that refers to baked or cold-formed cereal-based snack bars, and may contain other ingredients such as fruit, nuts, seeds, chocolate, yoghurt, and a variety of other fillings and/or toppings. By changing the ingredients nutritional value of muesli bar can be modified. In this research, protein-rich and energy-high muesli bars have been produced, because they contain a higher amount of fat, proteins and sugar. However, fats and sugars were not added but come from specific ingredients (hazelnuts, walnuts, chia seeds, sesame, sunflower and pumpkin seeds, oat flakes, etc.). Four muesli bar formulations were developed, two with hazelnuts and two with walnuts, added in the amount of 25% and 50%, respectively. The other ingredients were added in the same amount. The product was dried at 80°C for several hours. The composition, polyphenolic compounds and antioxidant capacity were determined in the products before and after drying. Also, muesli bars were sensory evaluated.

In this paper, the influence of biological acid dough with a strain of lactic acid bacteria (Lactobacillus plantarum) on the properties of the dough and the addition of sourdough on the quality of crackers was investigated. Changes in total titratable acidity and pH were monitored during the fermentation of the sourdough (24 hours). In the dough for the production of gluten-free crackers, the influence of the addition of sourdough on the total titratable acidity and pH value was examined. The content of water, protein, fat, starch, crude fiber, pH value and total titratable acidity was determined by flour samples for the production of gluten-free crackers and gluten-free crackers. The influence of sourdough on the sensory properties of crackers was examined. The mineral composition of zinc was determined and the contribution of the daily recommended intake was assessed. In samples of crackers subjected to storage for 5, 10, 20 and 30 days, a change in water content was monitored. The length of fermentation had a significant impact on the dynamics of pH change and on the total titratable acidity during the fermentation of sourdough. The results of the study showed that the control sample has a higher pH value than the samples with sourdough. The reason for that is the development of acetic acid during fermentation. The change in water content in the crackers over 30 days was significantly higher in the control sample compared to the samples with sourdough. Crackers with sourdough contain a significantly higher percentage of protein, ash, fiber, zinc at the expense of reducing carbohydrates.