Recent technological developments have led to a significant increase in energy consumption in daily life. The search for alternative means of energy production has become an important task for ...applied sciences and modern technology. Hydrogen technology has great potential as a source of clean energy. The production of green hydrogen is a desirable and beneficial way to contribute to the decarbonization of the energy sector. In response to the demand for environmentally friendly and economically feasible approaches, biohydrogen production from waste materials has recently attracted interest. Waste materials from industrial or municipal production can be used as low-cost substrates for biohydrogen production through microbial degradation. Green energy needs could be met through a form of sustainable development that moves hand in hand with the harnessing of the microbial potential of waste biomass. Reuse of waste materials leads to pollution reductions and energy recycling. The aim of this review is to provide informative insights for researchers and engineers to help them better understand microbial biohydrogen production from low-cost waste substrates, such as industrial wastewater and waste activated sludge.
Silver nanowires were prepared by the polyol process with ethylene glycol as a solvent and reducing agent, silver nitrate as a silver source, polyvinylpyrrolidone as a growth-directing agent, ...stabilizer and agglomeration prevention agent, and copper chloride as a growth control agent. The product was characterized by UV–Vis spectroscopy, scanning electron microscopy, and X-ray diffraction. The biocidal activity of silver nanowires was investigated using the disc diffusion method on the bacteria Bacillus subtilis and Pseudomonas aeruginosa and the fungi Aspergillus niger and Candida albicans. X-ray diffraction and scanning electron microscopy showed that, in addition to silver nanowires, the product also contains quasi-spherical silver nanoparticles and some silver chloride. Based on the results of UV–Vis spectroscopy and scanning electron microscopy, it was estimated that the diameter of the nanowires is 200–300 nm. Nanowires have shown weak bactericidal and good fungicidal activity. Silver nanowires showed particularly good activity in inhibiting the growth of Candida albicans.
Biosorption is becoming increasingly important for the treatment of pollutants due to its cost-effectiveness, environmental friendliness and efficiency. For a more sustainable environment, more ...studies need to focus on the application of real industrial effluents. Increasing the initial concentration of activated sludge increases the specific surface area of the sludge, which allows for greater sorption of sorbates. The optimal initial concentration of activated sludge in the process of biosorption of pollutants from pharmaceutical effluent was 5.12±0.13 g/L. The biosorption process can be described by the Temkin model, where the estimated values of B
T
and A
T
ranged from 29.11 to 76.08 and from 1.10 to 1.48 L/g, respectively. The overall efficiency of the biosorption process ranged from 9.5 to 40.2%. The removed toxicity averaged 41.1±7.88% for all experiments.
Nanoparticles are capable of making more durable and stronger materials with better chemical resistance. They are used for a wide range of applications. Likewise, the potential of metal nanoparticles ...as antimicrobial agents has been widely studied. In this work, we investigate various nanoparticles (Al, Ni, Ag) incorporated into epoxy coating. The anticorrosion and antibacterial properties of the unmodified and modified coatings were evaluated. According to the SEM and EDS analyses, the coating did not contain agglomerates, which confirms the quality of the dispersion of inorganic nanoparticles in the coating. After 24 h and 10days immersions in a 3.5 wt.% NaCl solution, the corrosion behaviour for all nanocomposite was studied by means of EIS investigations. The study included the evaluation of the inhibition zone of the nanoparticles and the antimicrobial properties of the nanocomposite. It was found that the nanoparticles of Al and Ag provide excellent antibacterial properties. The epoxy nanocomposite with Al NP showed the migration of ions in the range from 0.75 to 1 mg/L in a wastewater solution for 30 days, indicating a potential for antimicrobe activity. The 1% Al NP epoxy nanocomposite showed good anticorrosion and antibacterial properties and demonstrated great potential for applications in pipelines.
In this study, different concentrations of aluminium nanoparticles (Al NP) were incorporated into epoxy resin and epoxy paint. Here, we present a detailed systematic study of different methods of ...incorporating inorganic nanoparticles into epoxy coating. This work aims to obtain an epoxy coating with anticorrosion and antibacterial properties. The physical properties of coatings such as thickness, hardness, colour, and adhesion did not change with the addition of nanoparticles. According to the SEM and EDS analyses, the distribution effect of Al NPs in epoxy coating was better with ultrasonic homogenisation than with mechanical stirring. The EIS and SECM measurements were used to investigate corrosion resistance. The coating with 1.0 wt.% Al NP showed the best physical and chemical properties. SECM examination indicated that nanoparticles in epoxy resin increase the protection efficiency by 25.75% and in the epoxy paint by 40.89%. The results also showed the antibacterial activity of aluminium nanoparticles by inhibiting the growth of biofilm-forming bacteria such as P. aeruginosa and B. subtilis.
The release of oil into the environment represents a pervasive problem stemming from oil exploration, accidents, transportation and releases from landfills, storage facilities or industrial plants. ...Compared to conventional and costly techniques, bioremediation is an attractive and promising alternative, as it can selectively degrade pollution without affecting the natural features of the site and the flora and fauna living there. In this study, the isolation, identification and characterization of autochthonous bacterial strains from a crude oil-contaminated soil sample was carried out under batch conditions over a period of 28 days. The initial colony forming units value for bacteria was 1.15 × 109/g of soil. The results show that the activity of bacteria was highest at a pH of 7.25. Based on morphology, biochemical tests and an analysis of MALDI TOF, isolated autochthonous bacterial species were identified as Bacillus megaterium, Bacillus licheniformis, Bacillus cereus and Pseudomonas chlororaphis. Since allochthonous bacteria are not highly efficient in a new environment due to their low adaptability and competition with indigenous microorganisms, these autochthonous microorganisms play a pivotal role in enhancing the bioremediation process on an applicable, industrial scale. This advancement aligns with the principles of sustainable development and the green economy, as purified soil is suitable for rational reuse in the environment.
The manufacture of pharmaceutical products generates wastewater that contains a variety of specific pollutants. The application of biological treatment with activated sludge is a commonly used ...process in industrial wastewater treatment with the aim of removing organic compounds by combining biosorption with biodegradation as a metabolic reaction of microorganisms, which are environmentally friendly processes. The efficiency of biosorption process ranged from 9.5 to 40.2%, with the values removal efficiency of toxic compounds ranging from 22.61 to 60.33%, while the overall biodegradation efficiency of organic pollutants ranged from 51.30 to 60.60%. By combining the process of biosorption and biodegradation, the optimal concentration of activated sludge was 4.96 ± 0.23 g dm
−3
for treating real pharmaceutical industrial wastewater. The morphology of the activated sludge maintained its structure, indicating that the activated sludge is resistant to changes in the pharmaceutical industrial wastewater treatment system.
•Apple and tobacco waste mixture was efficiently composted during 22days.•Physical–chemical and microbiological properties of the mixture were suitable the process.•Evaluation of selected ...mathematical model showed good prediction of the temperature.•The temperature curve was a “mirror image” of the oxygen concentration curve.•The peak values of the temperature were occurred 9.5h after the peak oxygen consumption.
Efficient composting process requires set of adequate parameters among which physical–chemical properties of the composting substrate play the key-role. Combining different types of biodegradable solid waste it is possible to obtain a substrate eligible to microorganisms in the composting process. In this work the composting of apple and tobacco solid waste mixture (1:7, dry weight) was explored. The aim of the work was to investigate an efficiency of biodegradation of the given mixture and to characterize incurred raw compost. Composting was conducted in 24L thermally insulated column reactor at airflow rate of 1.1Lmin−1. During 22days several parameters were closely monitored: temperature and mass of the substrate, volatile solids content, C/N ratio and pH-value of the mixture and oxygen consumption. The composting of the apple and tobacco waste resulted with high degradation of the volatile solids (53.1%). During the experiment 1.76kg of oxygen was consumed and the C/N ratio of the product was 11.6. The obtained temperature curve was almost a “mirror image” of the oxygen concentration curve while the peak values of the temperature were occurred 9.5h after the peak oxygen consumption.
Abstract
This article reports on a study in which a new conceptual framework for fostering
a positive attitude towards teaching in higher education
(PATTHE) was developed. The PATTHE framework builds ...on a holistic four‐dimensional theoretical concept and is not limited by the specificity of teaching within a particular discipline or national higher education context. The four dimensions of PATTHE pertain to (a) emotional dimension, (b) professional development, (c) constructivist approaches to teaching, and (d) the teaching and research nexus; all of which are relevant for empowering quality teaching at personal, institutional and/or national higher education policy levels. The purpose of our study was to test and analyse this conceptual framework. Creative qualitative research methods were used including identification of keywords, evoking participant opinions through visual materials, reactions to vignettes, and by documenting discussions regarding the proposed PATTHE conceptual framework. A purposive and critically informed approach was used for the selection of twelve higher education experts as research participants. Responses from the selected education developers were collected through an online protocol system. Research results revealed that participant reflections on a positive attitude towards teaching showed a high level of agreement with the proposed conceptual framework; the proposed theoretical concept is thereby deemed well‐constructed and acceptable with minimal extensions.
