Examining plasma-generated ozone and nitric oxide's role in synthetic textile dye water remediation and ecotoxicological analysis.

Synthetic dyes produced by the textile dyeing industry and released into wastewater contribute significantly to water pollution. This study explores the efficacy and versatility of a novel multi-electrode dielectric barrier discharge (MEDBD) plasma system that mainly generates ozone (O3 generator) and nitric oxide (NO generator) selectively to degrade various synthetic textile dyes, namely Methylene Blue (MB), Congo Red (CR), Methyl Orange (MO), Crystal Violet (CV), and Evans Blue (EB). Plasma achieved selective enrichment of O3 and NO by utilizing optimized plasma generation duty cycles of 15% and 100%, respectively. The proposed O3 generator plasma involves plasma-generated aqua electron impact, excited species, and reactive oxygen species notably O3, which degrades synthetic textile dyes into simple forms such as CO2, H2O, and N2. This approach achieved over 95% degradation of the above synthetic textile dyes when employing the O3 enriched plasma with 2.44 ± 0.21 W of power. Ecotoxicological evaluation, including microbial, human cell, and phytotoxicity evaluations of the O3 generator plasma for MB and CR dye-contaminated water, underscored the potential of this plasma system for environmentally friendly dye degradation. Overall, this study promotes MEDBD plasma, particularly the O3 generator, as a sustainable and efficient solution for treating synthetic dye-contaminated water across industries.

Investigating the synergy of rapidly synthesized iron oxide predecessor and plasma-gaseous species for dye-removal to reuse water in irrigation.

This study explores a novel and sustainable approach to reusing textile wastewater for irrigation. This is investigated by degrading Evans blue dye, a model azo dye, in wastewater by combining iron oxide predecessor (IOP) catalyst with gaseous species generated by multi-electrode cylindrical plasma device (MCPD). Analysis of IOP-plasma gaseous species revealed the generation of different types of reactive oxygen species in solution which were responsible for degradation of model dye. Key factors influencing the degradation process were studied by performing optimization experiments that resulted in rates of up to 0.008 L mg-1 min-1, more than twice as fast as using plasma gas treatment alone. These studies included mechanistic response of MCPD generated gaseous species with the IOP. In particular, reusability testing of IOP affirmed the robustness and performance efficiency up to three cycles. Finally, toxicity analysis revealed not only reduced negative effects on plant growth by the treated wastewater, but also it can used as minerals to plants. These findings highlight the feasibility of the IOP-MCPD system as a sustainable and eco-friendly solution to reduce scarcity of water in irrigation by treating textile effluent.

Enhanced dye degradation using plasma bubbles for the sustainable environmental remediation.

This study proposes a novel and eco-friendly approach for wastewater treatment using plasma jet technology under bubble condition. This method allows for the controlled production of highly reactive hydroxyl radicals (OH•) while minimizing unwanted interactions with nitrogen in the air. The presence of bubbles in liquid significantly boosts the diffusion of OH• within the wastewater, leading to a two-fold increase in degradation rate compared to normal condition. The effectiveness of the treatment was confirmed through ultraviolet-visible spectroscopy, which showed a significant decrease in rhodamine B and methyl orange absorbance peaks. Raman spectroscopy further revealed structural changes in both pollutants, indicating successful degradation. Additionally, plasma characteristics like power, electron temperature, and density were monitored to gain deeper insights into the underlying mechanism. Importantly, the process minimizes the formation of harmful secondary pollutants such as ozone and nitrogen oxides. These pollutants were found under concentration of 0.14 mg m-3 which is below established safety thresholds, adhering to World Health Organization guidelines. This research demonstrates that plasma jet treatment in bubble condition not only enhances the degradation efficiency of pollutants in wastewater but also minimizes the formation of harmful byproducts. This represents a significant breakthrough in developing sustainable wastewater treatment technologies.

Biocompatible plasma-treated liquids: A sustainable approach for decontaminating gastrointestinal-infection causing pathogens.

Nosocomial infections are a serious threat and difficult to cure due to rising antibiotic resistance in pathogens and biofilms. Direct exposure to cold atmospheric plasma (CAP) has been widely employed in numerous biological research endeavors. Nonetheless, plasma-treated liquids (PTLs) formulated with physiological solutions may offer additional benefits such as enhanced portability, and biocompatibility. Additionally, CAP-infused long-lived reactive oxygen and nitrogen species (RONS) such as nitrite (NO2-), nitrate (NO3-), and hydrogen peroxide (H2O2) can synergistically induce their antibacterial activity. Herein, we investigated those argon-plasma jet-treated liquids, including Ringer's lactate (RL), phosphate-buffered saline (PBS), and physiological saline, have significant antibacterial activity against nosocomial/gastrointestinal-causing pathogens, which might be due to ROS-mediated lipid peroxidation. Combining the conventional culture-based method with propidium iodide monoazide quantitative PCR (PMAxx™-qPCR) indicated that PTLs induce a minimal viable but non-culturable (VBNC) state and moderately affect culturable counts. Specifically, the PTL exposure resulted in pathogenicity dysfunction via controlling T3SS-related effector genes of S. enterica. Overall, this study provides insights into the effectiveness of PTLs for inducing ROS-mediated damage, controlling the virulence of diarrheagenic bacteria, and modulating homeostatic genes.

Evaluation of degradation efficacy and toxicity mitigation for 4-nitrophenol using argon and air-mixed argon plasma jets.

This paper investigates the effects of argon (Ar) and that of Ar mixed with ambient air (Ar-Air) cold plasma jets (CPJs) on 4-nitrophenol (4-NP) degradation using low input power. The introduction of ambient air into the Ar-Air plasma jet enhances ionization-driven processes during high-voltage discharge by utilizing nitrogen and oxygen molecules from ambient air, resulting in increased reactive oxygen and nitrogen species (RONS) production, which synergistically interacts with argon. This substantial generation of RONS establishes Ar-Air plasma jet as an effective method for treating 4-NP contamination in deionized water (DW). Notably, the Ar-Air plasma jet treatment outperforms that of the Ar jet. It achieves a higher degradation rate of 97.2% and a maximum energy efficiency of 57.3 gkW-1h-1, following a 6-min (min) treatment with 100 mgL-1 4-NP in DW. In contrast, Ar jet treatment yielded a lower degradation rate and an energy efficiency of 75.6% and 47.8 gkW-1h-1, respectively, under identical conditions. Furthermore, the first-order rate coefficient for 4-NP degradation was measured at 0.23 min-1 for the Ar plasma jet and significantly higher at 0.56 min-1 for the Ar-Air plasma jet. Reactive oxygen species, such as hydroxyl radical and ozone, along with energy from excited species and plasma-generated electron transfers, are responsible for CPJ-assisted 4-NP breakdown. In summary, this study examines RONS production from Ar and Ar-Air plasma jets, evaluates their 4-NP removal efficacy, and investigates the biocompatibility of 4-NP that has been degraded after plasma treatment.

Nitric oxide water-driven immunogenic cell death: Unfolding mitochondrial dysfunction's role in sensitizing lung adenocarcinoma to ferroptosis and autophagic cell death.

Non-small cell lung cancer (NSCLC), particularly lung adenocarcinoma (LUAD), significantly influences cancer-related mortality and is frequently considered by poor therapeutic responses due to genetic alterations. Cancer cells possess an inclination to develop resistance to individual treatment modalities, thus it is necessary to investigate several pathways simultaneously to obtain insights that will aid in the establishment of improved therapeutic approaches. Exploring regulated cell death (RCD) mechanisms offers promising avenues to augment immunotherapy by reshaping the tumor microenvironment (TME). Here, we investigated the prospective of microwave plasma-infused nitric oxide water (NOW) to initiate immunogenic cell death (ICD) while concurrently modulating autophagy and ferroptosis signaling in LUAD-associated A549 cells. Plasma treatment results in stable NO species nitrite/nitrate (NO2-/NO3-) in the water, altering its physicochemical properties. Analysis of ICD markers reveals increased expression of damage-associated molecular patterns (DAMPs) at both protein and mRNA levels post-NOW exposure. Intracellular reactive oxygen and nitrogen species (RONS) accumulation suggests NO-mediated mitochondrial dysfunction, triggering autophagy induction. Flow cytometry and western blotting confirm alterations in autophagy regulators Beclin 1 and SQSTM1. Furthermore, NOW treatment induces lipid peroxidation and upregulates ferroptosis-associated genes, as determined by qRT-PCR. Transmission electron microscopy (TEM) imaging reveals autophagosome formation and loss of cristae structures, corroborating the occurrence of autophagy and ferroptosis. Our findings propose that NOW may considered as inducer of ICD and the stimulation of other RCD-related proteins may enhance the anti-tumor immunogenicity.

Mitigation of T3SS-mediated virulence in waterborne pathogenic bacteria by multi-electrode cylindrical-DBD plasma-generated nitric oxide water.

S. enterica, S. flexneri, and V. parahaemolyticus bacteria are globally recognized to cause severe diarrheal diseases, consisting of Type III Secretion System (T3SS) effectors that help in bacterial infection and virulence in host cells. This study investigates the properties of multi-electrode cylindrical DBD plasma-generated nitric oxide water (MCDBD-PG-NOW) treatment on the survival and virulence of S. enterica, S. flexneri, and V. parahaemolyticus bacteria. The Colony Forming Unit (CFU) assay, live/dead cell staining, lipid peroxidation assay, and bacteria morphological analysis showed substantial growth inhibition of bacteria. Moreover, to confirm the interaction of reactive nitrogen species (RNS) with bacterial membrane biotin switch assay, DAF-FM, and FTIR analysis were carried out, which established the formation of S-nitrosothiols in the cell membrane, intracellular accumulation of RNS, and changes in the cell composition post-PG-NOW treatment. Furthermore, the conventional culture-based method and a quantitative PCR using propidium monoazide showed minimal VBNC induction under similar condition. The efficiency of bacteria to adhere to mammalian colon cells was significantly reduced. In addition, the infection rate was also controlled by disrupting the virulent genes, leading to the collapse of the infection mechanism. This study provides insights into whether RNS generated from PG-NOW might be beneficial for preventing diarrheal infections.