Given the increasing prevalence of antibiotic-resistant microorganisms, alternative disinfection strategies are required. This study explores the antimicrobial potential of cold atmospheric plasma (CAP) as a non-thermal decontamination method for medical applications. The results confirm the efficacy of cold microwave plasma jets in the inactivation of Staphylococcus epidermidis, Escherichia coli, Cutibacterium acnes, and Nakaseomyces glabratus. Optimal treatment conditions ensuring both the antimicrobial efficacy and the safety for living tissue were established. Experiments in enclosed or open-air environment and the use of colorimetric agents confirmed that RONS, rather than UV radiation, are primarily responsible for microbial inactivation. Possible inhibition mechanisms induced by the CAP treatment were examined using scanning (SEM) and transmission (TEM) electron microscopy. The analyses revealed progressive morphological and intracellular changes in yeast cells following the plasma treatment, including localized thinning and perforation of the cell wall, vacuole enlargement, enhanced vesicle formation, protoplast aggregation and leakage of intracellular content.

Iodine-based contrast agents (ICMs) are crucial substances in medical imaging because of their potent X-ray characteristics and chemical stability. However, their persistence and poor removal in conventional wastewater treatment have led to increasing environmental concern. Although ICMs exhibit low acute toxicity, their transformation during water disinfection can generate iodine-based disinfection by-products (I-DBPs), like iodo-trihalomethanes, which display notable cytotoxic, genotoxic, and ecotoxic effects and compromise drinking water quality. Advanced oxidation processes (AOPs) have become promising methods for breaking down persistent ICMs and limiting the formation of I-DBPs. Techniques including ozonation, UV/H2O2, UV/chlorine, photocatalysis with TiO2, Fenton reactions, and electrochemical oxidation utilize highly reactive radicals to decompose persistent compounds like iopamidol, iohexol, iopromide, and diatrizoate. Despite high degradation efficiencies under laboratory conditions, limitations such as incomplete mineralization, secondary product formation, and elevated operational costs hinder large-scale implementation. Future research should focus on optimizing AOP conditions under realistic water matrices, evaluating by-product toxicity, and developing cost-effective hybrid systems. Advancing these technologies is critical to reducing the environmental burden of ICMs and safeguarding aquatic ecosystems and public health.

This study examines the decontamination efficacy of cold atmospheric plasma (CAP) against Staphylococcus epidermidis and Escherichia coli, with emphasis on surface scanning parameters and resistance potential. Bacterial cultures on solid nutrient media were treated using a non-thermal microwave plasma torch operated with high-purity argon (4.6) at 5 Slm and 12–13 W. Treatment was systematically varied in scanning direction, speed, and duration. Results indicate that exposure time was the main factor influencing bacterial inhibition, whereas direction and speed exerted only minor effects. E. coli exhibited greater susceptibility compared to S. epidermidis. Repeated exposure experiments revealed no evidence of resistance development.

Cold atmospheric-pressure plasma is a promising tool for sustainable agriculture due to its generation of reactive oxygen and nitrogen species (RONS). This study evaluated direct corona discharge and plasma-activated water (PAW) treatments on onion bulbs at seven field sites. Bulbs were treated by corona discharge (2 & times; 10 s or 2 & times; 40 s) or soaked for 24 h in PAW produced by dielectric barrier discharge. Volatile compounds were analyzed by GC-MS and PTR-TOF-MS. The 2 & times; 10 s corona treatment increased average bulb weight by 7.5%, with positive responses at six of seven sites, and enhanced propanal concentration at five sites (mean +26.3% vs. control). Water-based treatments showed only minor, nonsignificant effects.

We analyzed the operation and characteristics of a radio frequency-driven low-pressure argon gas-fed plasma source, the result being that the extracted ion current strongly correlates with the density of argon metastables. Such an insight provides a practical advantage for the future engineering of the described plasma source. The plasma source exploits a Birdcage resonator and operates on the principle of electron cyclotron resonance (ECR), with a static magnetic field generated by a pair of Helmholtz coils. The general performance of the source was determined by measuring the extracted ion current at different flux densities of the stationary magnetic field near the resonance condition. This ion current was correlated with the plasma parameters obtained through optical emission spectroscopy (OES). Using the branching fraction method (BFM), the lowest argon metastable density (1s5 in Paschen’s notation) was calculated. Both correlated quantities confirm that the source performs best at ECR.

In this study, plasma activated water (PAW) was prepared by a pin-hole discharge, generating plasma directly in liquids with air flowing into the discharge. Radish (Raphanus sativus) plants were grown in pots filled with soil for 30 d. Pots were divided to 4 variants based on the PAW application: PAW prepared from distilled water (PAW DW), PAW prepared from tap water (PAW TW), foliar application of PAW on leaves and irrigated by TW (TW/PAW DW) and control group irrigated by TW. Results have indicated enhancement of the growth of the plant fresh matter in all variants treated by PAW. Vitality of the plants was determined by chlorophyll fluorescence. Fluorescence measurement results have shown inhibition of photosynthesis activity in case of plants treated with PAW compared to control group (TW), which means the treatment of plants with PAW lowers the overall vitality. Elemental analysis results showed that the PAW treatment of plants increased the content of nitrogen in the root part of the radish plants. The sensory evaluation showed that the PAW treatment influenced a certain taste and aesthetic characteristics of R. sativus. Overall, the foliar application of PAW seems to be more convenient option as a plant fertilizer compared to the soil irrigation.

This work studies the decontamination efficacy of different plasma treated liquids (PTLs) on bacteria from the genera Staphylococcus and Pseudomonas, both commonly associated with various infections. Clinical isolates and reference strains were used, to ensure the relevance to real-life applications. Bacterial suspensions were exposed to studied PTLs and to different comparative solutions that help dissect the mechanisms behind the observed antimicrobial effects. These comparative solutions comprised standard solutions of major reactive species (hydrogen peroxide, nitrites, nitrates) typically found in PTLs, solutions simulating the chemical composition of PTLs, and solutions adjusted to different pH levels to isolate the role of acidity in bacterial inactivation. The antimicrobial effects of studied solutions were examined at various contact times from 10 min up to 24 h. This allowed for a comprehensive understanding of both immediate antimicrobial effects and the persistence of PTL´s activity over time. The findings of this research demonstrate a superior antimicrobial efficacy of plasma treated liquids compared to the other studied solutions. Neither the individual standard solutions of reactive species, the solutions simulating the chemical composition of PTLs, nor pH-adjusted solutions were able to match the antimicrobial efficacy of the tested PTLs. Although it has been found that for some bacterial species, pH of the PTL may play a key role in the decontamination efficacy. The study also shows that different PTLs vary in their antimicrobial efficacy, depending on the specific formulation and the type of targeted microbial species. These differences in bacterial response may be influenced by factors such as cell wall structure, antioxidant capacity, and pH tolerance. In conclusion, this work supports the potential of indirect cold plasma treatment (via PTLs) for antimicrobial purposes. It highlights the complex interplay of factors involved in microbial inactivation and offers deeper insight into the differing responses of gram-negative and gram‑positive bacterial species to various PTLs. Furthermore, the study provides an overview of the antimicrobial effects of individual components present in PTLs across a wide range of concentrations and pH conditions. This may help other researchers compare the efficacy of different antimicrobial agents and explore potential mechanisms of inhibition.

The ozone destruction at higher gas temperatures was studied in a quartz cuvette. The cuvette was heated by a resistance wire wound on the outer surface of the cuvette. The cuvette was filled with ozone and the time dependence of ozone concentration in the cuvette was measured by absorption spectroscopy. The rate constant for ozone decay was derived from this time dependence. The influence of the rate constant on surface condition (the surface concentration of adsorbed oxygen atoms and molecules) was studied. The surface concentration of adsorbed oxygen atoms was changed by reactions with gaseous molecular oxygen just before the cuvette was filled by ozone. The cuvette temperature was set to 40, 50 and 60 ◦C. The measured rate constants increase with increasing temperature from the value 1.27 × 10−4 s−1 to 1.88 × 10−4 s−1. The influence of temperature and cuvette surface coverage on ozone decay constants is discussed.

Plasma agriculture as a novel approach started to gain more attention in the last decade. In this work, the effect of plasma activated water (PAW) prepared with different plasma sources from three types of water on germination and growth of Cucumis melo L. was studied. The best effect of PAW from distilled water on the growth of seedlings was observed when prepared using the surface-wave-sustained microwave discharge. The effect of artificially prepared plasma activated water (ArtPAW) was studied, however, it was found that while ArtPAW may cause similar effects to the plasma PAW, the effect is not as significant and consistent. Further, PAW was prepared from tap and wastewater. It was found that PAW from wastewater has positive effects on both germination of the seeds and the growth of the seedlings. The root elongation of C. melo after application of plasma treated wastewater increased up to 130% compared to the control. Moreover, it was found that plants grown in PAW from wastewater contained significantly higher concentrations of plant nutrients. Therefore, it shows a promising approach for the application of non-thermal plasma in plant fertilization and a method of wastewater reuse after plasma treatment.

Contamination of the environment with toxic metals such as cadmium or lead is a worldwide issue. The accumulator of metals Cannabis sativa L. has potential to be utilized in phytoremediation, which is an environmentally friendly way of soil decontamination. Novel non-thermal plasma-based technologies may be a helpful tool in this process. Plasma activated water (PAW), prepared by contact of gaseous plasma with water, contains reactive oxygen and nitrogen species, which enhance the growth of plants. In this study, C. sativa was grown in a short-term toxicity test in a medium which consisted of plasma activated water prepared by dielectric barrier discharge with liquid electrode and different concentrations of cadmium or lead. Application of PAW on heavy metal contaminated C. sativa resulted in increased growth under Pb contamination as was determined by ecotoxicology tests. Furthermore, the PAW influence on the bioaccumulation of these metals as well as the influence on the nutrient composition of plants was studied primarily by applying Laser-induced breakdown spectroscopy (LIBS). The LIBS elemental maps show that C. sativa accumulates heavy metals mainly in the roots. The results present a new proof-of-concept in which PAW could be used to improve the growth of plants in heavy metal contaminated environment, while LIBS can be implemented to study the phytoremediation efficiency.

The ozone destruction was studied in a quartz cuvette. The time dependence of ozone concentration was measured by absorption spectroscopy. From this time dependence the pseudo first-order rate constant was derived. This rate constant depends on surface condition - the surface concentration of adsorbed oxygen atoms. This surface concentration was changed by reactions of adsorbed oxygen atoms with gaseous molecular oxygen just before the cuvette was filled by ozone. The decrease of atomic oxygen surface concentration leads to the decrease of rate constant for ozone destruction. The measured rate constants were in range 9.0 × 10−5 s−1 to 9.8 × 10−5 s−1.

This work focuses on the antimycotic effects of the plasma gun as a potential tool for the treatment of superficial infections. Candida glabrata was chosen as a model microorganism. The preliminary tests have been done on the agar plates to establish the basic plasma parameters. To render this research more appropriate to the real application, more complex inoculation substrates, pork skin and 3D-printed models of the dog ear canal have been used. The results of this work confirm the high efficiency of cold plasma in the inhibition of yeasts on different surfaces and will lead to further experiments.

Plasma treated water was prepared by non-thermal plasma systems using plasma interaction above or inside liquid or in a remote bubbling regime. Plasma treated water prepared from distilled, tap or water solutions was characterised by physical properties (pH, conductivity) and colorimetric determination of stable chemical species (hydrogen peroxide, nitrites, and nitrates). Its quality was evaluated with respect to its possible utilization in sustainable agriculture and medicine applications.

The indicators are comprised of TiO2, Remazol Brilliant Blue R, glycerol, and polymer. Two different polymer matrices, poly(vinyl acetate) (PVAC) or (carboxy)methyl cellulose (CMC) were used. The indicators were printed on a plastic foil and covered with a UV curable coating. Data for the kinetic study of photocatalytic reduction and oxidation were gathered with reflectance spectrophotometer and the kinetic analysis was based on the change of the indicator's optical density. Both indicators were successfully activated with UVA and both detected oxygen. The rate of oxidation depended on percentual oxygen concentration, increasing with increasing oxygen concentration. The PVAC based indicator was much quicker to detect oxygen than its CMC counterpart, the former having a color change response to oxygen that is easily detected by naked eye in just one minute.

The objective of this research is to describe the impact of different advanced oxidation processes used for the removal of sulfamethoxazole on wastewater quality.

Four different cold plasma sources were directly applied onto a 24h inoculum of Candida glabrata inoculated on agar plates, within the limits of in vitro experiment. Their effects were compared and evaluated with respect to the size and stability of the inhibition zones formed in the posttreatment cultivation. The results prove significant inhibitory cold atmospheric-pressure plasma effects on the yeast C. glabrata. The overall inhibitory effects are directly proportional to the treatment time, the applied power, and the overall functioning of the plasma source and indirectly proportional to the initial cell concentration, although this factor was less significant compared to the other examined factors. The unipolar microwave torch was found to be the most effective in the inhibition of C. glabrata.

The paper gives the detailed information about a newly developed plasma system applicable for conductive target non-thermal plasma indirect treatment. High voltage microsecond duration pulses delivered in the kHz range are used to ignite a discharge in a glass funnel vessel flushed with argon and equipped with a needle electrode. An air dielectric barrier discharge (DBD) can subsequently be generated if a grounded grid is set a few millimeters apart from the thin glass plate constituting the funnel base, in the funnel-DBD setup. Thus, this air DBD operates with its powered electrode consisting in the transient argon streamer discharge spreading inside the funnel and over the glass plate. This “plasma electrode DBD” is characterized using time-resolved ICCD imaging together with voltage and current probes. This work reports for the first time the funnel-DBD proof of concept operation and its potentialities for large surface decontamination. Argon and air plasma temporal and spatial development is documented and analyzed while electrical characterization using Lissajous plots provide key information on the power and capacitances of the funnel-DBD setup. It is reported that the funnel-DBD operates as a large surface and low power discharge. As with any air-DBD plasma, the modulation of the power density delivered across the air-DBD, processed with changing the pulse repetition rate, results in the control of the ozone concentration. Beyond the plasma electrode-DBD development and characterization, the main motivation of this work is the treatment of conductive samples with the perspective of large surface decontamination. Preliminary demonstrations of the bacterial and yeast inhibition are thus reported for in vitro cultivations through indirect treatment with the funnel-DBD delivering reactive nitrogen and oxygen species.

In this paper, an investigation of the interaction of a surface-wave-sustained argon plasma torch with liquids is presented. The plasma is produced by an electromagnetic wave traveling along the plasma–dielectric interface, and at the same time, the plasma is a part of this waveguide structure. Because the interaction of the plasma torch with water (liquid) results in modifications of the properties of both the treated water and the plasma itself, a detailed study of the effects in both media is required. The results of the experimental investigation of a surface-wave-sustained argon plasma torch interaction with liquids show significant changes in the plasma parameters, such as the electron excitation temperature Te and the average rotation temperature Trot. In addition, mechanical waves are produced both in the meniscus surface and in the plasma torch by the interaction between the plasma torch (ionized gas with charged particles and electric field) and the liquid surface, which is different from the effects produced by a neutral gas jet on a liquid surface. As a result of the plasma–water interaction, the water’s chemical and physical characteristics, such as the water conductivity, pH, and H2O2 concentration, are modified. As a possible application for water purification, the performed SWD treatment of model wastewater shows a significant variation in nitrate, ammonium, phosphate, and COD (chemical oxygen demand) concentration as a result of the treatment.

In recent years, nanoparticles have emerged as an important player in a broad range of applications, especially thanks to recent advances in their synthesis. The silver and copper nanoparticles are often used due to their antibacterial and fungicidal activities, and this article presents the results of the nanoparticle synthesis using electrical glow discharge generated directly in a volume of their salt solutions. Therefore, there is no influence of air (i.e. reactive nitrogen species) as it is usual in other commonly used approaches. Nanoparticles were prepared under various experimental conditions, and they were characterized by ultraviolet/visible spectrometry, dynamic light scattering, X-ray photoelectron spectroscopy, and high-resolution scanning electron microscopy. Particles were produced without any surfactant or stabilizing agent, and some of them showed higher resistance against agglomeration during their short-term (days) storage. The nanoparticle formation mechanism was confirmed by the fast camera imaging. Thus, the developed approach can be applied for simple environmentally friendly nanoparticle production for various applications.

This study compares the effects of nonthermal plasma treatment on quinine water solutions for two configurations-the corona-like discharge and the gliding arc discharge (GAD). Different electrolytes were added to the quinine solutions to modify the initial pH and enhance electrical conductivity for plasma discharge ignition directly in the liquid. A slightly higher quinine decomposition rate of 2.9 mu g W-1 after 5 min of the treatment was achieved by GAD. From measured spectra, it was found that the absorption maximum at 332 nm was split into two separated peaks in the acidic and basic solution. The study of the time stability of quinine solutions has revealed quinine instability and that postpreparation time has influenced the plasma treatment effect.