Use of Hydrothermal Carbonization and Cold Atmospheric Plasma for Surface Modification of Brewer’s Spent Grain and Activated Carbon

This paper presents results that show the effect of hydrothermal carbonization and subsequent cold plasma jet treatment with helium and argon on the structure and sorption properties of a material—spent brewery grain. Treatment of activated carbon, with a cold atmospheric plasma jet, was used comparatively. The effect of activation on the pore structure of the materials was carried out by the volumetric method at low pressure (N2, 77 K). The specific surface area as well as the total pore volume, average pore size, and pore size distribution were determined using different theoretical models. A high improvement in the sorption capacity parameter was obtained for hydrochars after cold atmospheric plasma jet treatment with an increase of 7.5 times (using He) and 11.6 times (using Ar) compared with hydrochars before cold atmospheric plasma jet treatment. The increase in specific surface area was five-fold (He) and fifteen-fold (Ar). For activated carbon, such a large change was not obtained after plasma activation. Regardless of the gas used, the increase in structural parameter values was 1.1–1.3

Biofouling Removal from Membranes Using Nonthermal Plasma

An essential aspect of wastewater treatment systems based on membranes is fouling, which leads to a decrease in their performance and durability. The membrane biofouling is directly related to the deposition of biological particles (e.g., microorganisms in the form of biofilm) on the membrane surface. The objective of the study was to investigate the possibility of using nonthermal plasma for membrane treatment to overcome the biofouling problem. The removal of biological cells from the membrane surface was performed in a dielectric barrier discharge (DBD) plasma. The biofoulant (i.e., activated sludge) on the surface of membranes was treated with plasma for 3–10 min, corresponding to a plasma dose of 13–42 J cm−2. Results of biofouling removal studies indicated that the process was very efficient (i.e., lethal effect was also observed) and dependent on the type of membrane and exposure time to the nonthermal plasma. Moreover, investigations of the influence of plasma treatment on extracellular polymeric substances of biofilms have confirmed the possibility of using plasma in the process of protein release from biological structures, which results in their destruction. It seems that plasma technologies can be part of the so-called hybrid methods of removing biological contamination of membranes used in wastewater treatment

Electrospun Polymer Nanofibers with Antimicrobial Activity

Nowadays, nanofibers with antimicrobial activity are of great importance due to the widespread antibiotic resistance of many pathogens. Electrospinning is a versatile method of producing ultrathin fibers with desired properties, and this technique can be optimized by controlling parameters such as solution/melt viscosity, feeding rate, and electric field. High viscosity and slow feeding rate cause blockage of the spinneret, while low viscosity and high feeding rate result in fiber discontinuities or droplet formation. The electric field must be properly set because high field strength shortens the solidification time of the fluid streams, while low field strength is unable to form the Taylor cone. Environmental conditions, temperature, and humidity also affect electrospinning. In recent years, significant advances have been made in the development of electrospinning methods and the engineering of electrospun nanofibers for various applications. This review discusses the current research on the use of electrospinning to fabricate composite polymer fibers with antimicrobial properties by incorporating well-defined antimicrobial nanoparticles (silver, titanium dioxide, zinc dioxide, copper oxide, etc.), encapsulating classical therapeutic agents (antibiotics), plant-based bioactive agents (crude extracts, essential oils), and pure compounds (antimicrobial peptides, photosensitizers) in polymer nanofibers with controlled release and anti-degradation protection. The analyzed works prove that the electrospinning process is an effective strategy for the formation of antimicrobial fibers for the biomedicine, pharmacy, and food industry

Electrospun polymer nanofibers for medical applications

Nanowłókna polimerowe wzbudzają obecnie ogromne zainteresowanie ze względu na ich potencjalne wykorzystanie w różnych procesach technologicznych, np. w produkcji tkanin lub wytwarzaniu membran. Włókna te wykazują wyjątkowe właściwości, takie jak: duży stosunek powierzchni do objętości oraz duża porowatość. Znanych jest kilka metod wytwarzania nanowłókien, jednak ze względu na prostotę, powtarzalność i niewielkie koszty, najpowszechniej stosowane jest przędzenie elektrostatyczne. Przedstawiono przegląd najnowszych osiągnięć w zakresie zastosowań nanowłókien polimerowych w medycynie, obejmujący zagadnienia materiałów opatrunkowych, uwalniania substancji aktywnych oraz inżynierii tkankowej.Polymer nanofibers are currently of great interest in terms of their potential use in various technological processes, e.g. in the manufacture of textiles or membranes. These fibers are characterized by extraordinary properties such as high surface to volume ratio and high porosity. There are several methods of manufacturing nanofibers, but for reasons of simplicity, repeatability and low cost, electrostatic spinning is the most common. The article presents a review of the latest developments in the application of polymer nanofibers in medicine, including such issues as bandage materials, release of active substances and tissue engineering

Use of Hydrothermal Carbonization and Cold Atmospheric Plasma for Surface Modification of Brewer’s Spent Grain and Activated Carbon

This paper presents results that show the effect of hydrothermal carbonization and subsequent cold plasma jet treatment with helium and argon on the structure and sorption properties of a material—spent brewery grain. Treatment of activated carbon, with a cold atmospheric plasma jet, was used comparatively. The effect of activation on the pore structure of the materials was carried out by the volumetric method at low pressure (N2, 77 K). The specific surface area as well as the total pore volume, average pore size, and pore size distribution were determined using different theoretical models. A high improvement in the sorption capacity parameter was obtained for hydrochars after cold atmospheric plasma jet treatment with an increase of 7.5 times (using He) and 11.6 times (using Ar) compared with hydrochars before cold atmospheric plasma jet treatment. The increase in specific surface area was five-fold (He) and fifteen-fold (Ar). For activated carbon, such a large change was not obtained after plasma activation. Regardless of the gas used, the increase in structural parameter values was 1.1–1.3