Iskanje po katalogu digitalne knjižnice

Opis: The aim of the study was to analyse two small wastewater treatment plants (SWTPs) and compare their treatment performance with the aim of developing a zero-waste strategy. The analyses showed that the second wastewater treatment plant had a problem with an increased phosphorus concentration in the wastewater as well as fluctuations in nitrogen removal. One of the key aspects was the recovery of phosphorus in the form of struvite precipitated on zeolite, which can be used as a fertiliser due to its significant nutrient content. The main benefit of the same SWTP is the separate collection of cellulosic material (labelled as sample RS), which has the potential for reuse as biochar, while from the first SWTP the sludge sample (labelled as sample SS) was taken and torrefied for comparison with RS. Both samples were torrefied at 250 ◦C and 350 ◦C in nitrogen and carbon dioxide atmospheres. The RS products obtained in CO2 atmosphere at 350 ◦C showed the best biochar properties, as they had a higher heating value (HHV) and a higher C content. Elemental analysis showed that the carbon content in RS and SS increased from 43 to 65 % and from 35 to 39 %, respectively. Measurement of the HHV of the torrefied RS product showed an increase from 17 to 26 MJ/kg, while for SS it increased from 15 to 17 MJ/kg. The comprehensive combustion index and the EMCI index show higher values for the RS samples torrefied at 350 ◦C. The H/C and O/C ratios are favourable for these samples, as the high quality of torrefied biomass is associated with the highest prices on the market. According to the TGA and FTIR analysis, the type of torrefaction atmosphere, in contrast to the torrefaction temperature, has little influence on the subsequent use of the torrefied samples in combustion. The results show that the integration of torrefaction for biochar production with phosphorus recovery by struvite precipitation is an efficient solution for waste management in small wastewater treatment plants.
Ključne besede: wastewater treatment plant efficiency, torrefication, N2 atmosphere, CO2 atmosphere, solid biofuels, proximate and ultimate analyses, thermogravimetry
Objavljeno v DKUM: 29.10.2025; Ogledov: 0; Prenosov: 6
Celotno besedilo (7,33 MB)

Opis: The study focuses on wastewater treatment by investigating the use of microalgae in cooperation with bacteria, in combination with ultrafiltration and membrane photobioreactors. This approach also enables the extraction of nutrients retained by the organisms, referred to as biomass, which can subsequently be utilised. Three different water samples were tested and introduced into the same system. The first sample was the influent water, the second was the mixed liquor, in which microalgae function in a consortium with bacteria, and the third was the effluent water, referred to as permeate. Parameters such as pH, electrical conductivity, turbidity, suspended solids, chemical oxygen demand, inorganic and organic carbon, organic content, and ion concentration were analysed using standard procedures. Certain samples required filtration for specific analyses. The results indicated that measured values varied among the three samples, which is expected, as certain inorganic compounds are consumed as nutrients for microalgae growth. In addition, some nutrients are released through the progressive degradation of more complex compounds. This work demonstrates the effective application of these technologies and methods for municipal wastewater treatment, with a focus on the new rotating membrane (R-HFM), which has a positive impact on system performance. Overall, this represents a promising investment in the future of water treatment.
Ključne besede: Wastewater treatment, bioreactors, ions, microalgae, ultrafiltration, biomass, photobioreactors, nutrient recycling, bacteria, microbial activity, domestic wastewater.  
Objavljeno v DKUM: 11.09.2025; Ogledov: 0; Prenosov: 1
Celotno besedilo (2,60 MB)

Opis: When children are confronted with the judicial system, they are particularly vulnerable to stressful and complex situations. Complying with international standards promoting child-friendly justice is crucial for preventing negative impacts on their development. The Slovenian legal system has implemented several measures to safeguard the rights and well-being of child victims and witnesses in criminal proceedings, such as excluding minors from direct confrontation with the accused, utilising videoconferencing for testimony, and establishing child-friendly spaces. The model of "Barnahus" or "Children’s House" has been adopted as well, emphasising a multidisciplinary approach to addressing child victims of sexual abuse and other crimes. The Supreme Court has actively pursued child-friendly justice, producing informative booklets to guide child witnesses through legal processes. These and other initiatives underscore Slovenia's commitment to balancing the rights of the accused with the protection and support of child victims in the criminal justice system while leaving room for further development.
Ključne besede: child-friendly justice, hearing a child, Children’s House, comprehensive treatment of minors, competency to testify
Objavljeno v DKUM: 19.08.2025; Ogledov: 0; Prenosov: 9
Celotno besedilo (429,38 KB)
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Opis: Employees in education, especially in residential treatment centres, face crisis situations as a result of emotional and behavioural problems/disorders of children and adolescents. They most often face various types of violence, self-aggression, use of illicit substances and abuse. Cases of children and adolescents with mental health problems are frequent. Crisis interventions differ with the complexity of the situation, and regardless of the approach, an appropriate relationship is crucial to any solution. The purpose of this article is to present and elaborate the most common crisis situations and some successful interventions in such cases.
Ključne besede: crisis situation, emotional and behavioural disorders, residential treatment centre, crisis intervention, professionals
Objavljeno v DKUM: 30.06.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (415,56 KB)
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Opis: In this research, a new approach to enzyme inactivation in flour was presented by supercritical technology, considered a sustainable technology with lower energy consumption compared to other technologies that use ultra-high temperature processing. Total protein concentration and the activity of enzymes α-amylase, lipase, peroxidase, polyphenol oxidase, and protease were determined in flour pre-treated with scCO2. During the study, it was observed that the activity of enzymes such as lipase and polyphenol oxidase, was significantly reduced under certain conditions of scCO2 treatment, while the enzymes α-amylase and protease show better stability. In particular, polyphenol oxidase was effectively inactivated below the 60% of preserved activity at 200 bar and 3 h, whereas α-amylase under the same conditions retained its activity. Additionally, the moisture content of the scCO2-treated spelt flour was reduced by 5%, and the fat content was reduced by 58%, while the quality of scCO2-treated flour was maintained. In this regard, the sustainable scCO2 process could be a valuable tool for controlling the enzymatic activity of spelt flour since the use of scCO2 technology has a positive effect on the quality of flour, which was verified by the baking performance of spelt flour with the baked spelt bread as an indicator of quality.
Ključne besede: food treatment, spelt flour, proteins, supercritical carbon dioxide, enzyme inactivation, defatted flour, carbon dioxide solubility
Objavljeno v DKUM: 17.04.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (2,72 MB)
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