Study of the Photodegradation of PBDEs in Water by UV-LED Technology.
Ontology highlight
ABSTRACT:
SUBMITTER: Valenti-Quiroga M
PROVIDER: S-EPMC8303597 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The UV-visible photodegradation of Naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid, CAS: 22204-53-1), one of the most used and detected non-steroidal anti-inflammatory drugs (NSAIDs) in the world, and its ecotoxicological consequences were investigated in an aqueous medium. The photo-transformation products were analyzed and the structures of photoproducts were elucidated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography coupled with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS). Seven photoproducts were detected and characterized, photo-transformation mechanisms have been postulated to rationalize their formation under irradiation. In silico Q.S.A.R. (Quantitative Structure-Activity Relationship) toxicity predictions were performed with the Toxicity Estimation Software Tool (T.E.S.T.) and in vitro assays were carried out on Vibrio fischeri bacteria. Some of the obtained photoproducts exhibit higher potential toxicity than Naproxen itself but the whole toxicity of the irradiated solution is not of major concern.
| S-EPMC7727023 | biostudies-literature
Project description:During manufacturing, therapeutic proteins may be exposed to ultraviolet (UV) radiation. Such exposure is of concern because UV radiation may cause photooxidative damage to proteins, which in turn could lead to physical changes such as aggregation and enhanced immunogenicity. We exposed murine growth hormone (mGH) to controlled doses of UV radiation, and examined the resulting chemical, physical and immunogenic changes in the protein. mGH chemical structure was analyzed by mass spectrometry after UV irradiation. Photooxidation products detected by mass spectrometry included methionine sulfoxide formed at Met[127] and Met[149] residues, and, tentatively assigned by MS/MS analysis, ether cross-links between original Ser[78] and Cys[188], and Cys[206] and Ser[213], and a thioether cross-link between Cys[17] and Cys[78] residues, transformation of Cys[189] into Ala, and various hydrolytic fragments. Physical damage to UV-irradiated mGH was monitored by infrared spectrometry, chromatographic analyses, and particle counting by micro-flow imaging. UV radiation caused mGH to aggregate, forming insoluble microparticles containing mGH with non-native secondary structure. When administered subcutaneously to Balb/c or Nude Balb/c mice, UV-irradiated mGH provoked antibodies that cross-reacted with unmodified mGH in a fashion consistent with a T-cell dependent immune response. In wildtype Balb/c mice, titers for anti-mGH IgG1 antibodies increased with increasing UV radiation doses.
| S-EPMC4066668 | biostudies-literature
Project description:The photodegradation of benzothiazole (BTH) in wastewater with the coexistence of iron oxides and oxalic acid under UV light irradiation was investigated. Results revealed that an effective heterogeneous photo-Fenton-like system could be set up for BTH abatement in wastewater under UV irradiation without additional H2O2, and 88.1% BTH was removed with the addition of 2.0?mmol?l-1 oxalic acid and 0.2?g?l-1 ?-Fe2O3 using a 500?W high-pressure mercury lamp (365?nm). The degradation of BTH in the photo-Fenton-like system followed the first-order kinetic model. The photoproduction of hydroxyl radicals (·OH) in different systems was determined by high-performance liquid chromatography. Identification of transformation products by using liquid chromatography coupled with high resolution tandem mass spectrometry provided information about six transformation products formed during the photodegradation of BTH. Further insight was obtained by monitoring concentrations of the sulfate ion (SO42-) and nitrate ion (NO3-) , which demonstrated that the intermediate products of BTH could be decomposed ultimately. Based on the results, the potential photodegradation pathway of BTH was also proposed.
| S-EPMC6030283 | biostudies-literature
Project description:Investigations were conducted to examine the effects of amine type and initial concentration, free chlorine concentration, UV light intensity, pH and tert-butyl alcohol (TBA) on the formation of dichloronitromethane (DCNM) under UV/chlorine. Methylamine (MA), dimethylamine (DMA) and poly-dimethyl diallyl ammonium chloride (PolyDADMAC) were selected as the amine precursors of DCNM. And the reaction products of amines were explored through observing the contents of various nitrogen under UV/chlorine. Experimental results indicated that the higher of the intensity of UV light, the concentration of amines and free chlorine, the greater of the amount of DCNM formation; the amine substance with simple structure is more likely oxidized to form DCNM, so the potential of MA to form DCNM is the largest among three amines; the formation of DCNM decreased with increasing pH from 6.0 to 8.0; due to adding TBA into the reaction solution, halogen and hydroxyl radicals were restrained which resulted the DCNM formation decreased. In the reaction process, the formation of DCNM from amines increased at the beginning, then decreased and almost disappeared due to photodegradation. During the formation and photodegradation of DCNM, the dissolved organic nitrogen could be transformed into the ammonia-nitrogen (NH3-N) and nitrate-nitrogen (NO3--N).
| S-EPMC7387445 | biostudies-literature
Project description:The purgaty One systems (cap+bottle) are portable stainless-steel water bottles with UV subtype C (UVC) disinfection capability. This study examines the bottle design, verifies disinfection performance against Escherichia coli, Pseudomonas aeruginosa, Vibrio cholerae, and heterotrophic contaminants, and addresses the public health relevance of heterotrophic bacteria. Bottles were inoculated with deliberately contaminated potable water and disinfection efficacy examined using colony forming unit (CFU) assay for each bacterial strain. The heterotrophic plate count (HPC) method was used to determine the disinfection performance against environmental contaminants at day 0 and after 3days of water in stationary condition without prior UVC exposure. All UVC irradiation experiments were performed under stationary conditions to confirm that the preset application cycle of 55s offers the desired disinfection performance under-tested conditions. To determine effectiveness of purgaty One systems (cap+bottle) in disinfection, inactivation efficacy or log reduction value (LRV) was determined using bacteria concentration between UVC ON condition and controls (UVC OFF). The study utilized the 16S ribosomal RNA (rRNA) gene for characterization of isolates by identifying HPC bacteria to confirm if they belong to groups that are of public health concern. Purgaty One systems fitted with Klaran UVC LEDs achieved 99.99% inactivation (LRV4) efficacy against E. coli and 99.9% inactivation (LRV3) against P. aeruginosa, V. cholerae, and heterotrophic contaminants. Based on the 16S rRNA gene analyses, the study determined that the identified HPC isolates from UVC irradiated water are of rare public health concern. The bottles satisfactorily inactivated the target pathogenic bacteria and HPC contaminants even after 3days of water in stationary condition.
| S-EPMC8446598 | biostudies-literature
Project description:BackgroundCotton is an important domesticated fiber used to manufacture a variety of products and industrial goods. During harvesting with cotton strippers and cotton pickers, it is contaminated with foreign matter from botanical and non-botanical sources which adversely affect the quality and consistency of cotton, and therefore reduces its market value. To improve the current grading done by the High Volume Instrument (HVI) and human inspectors, it was explored whether fluorescence imaging can be used for cotton foreign matter detection.ResultsEight types of botanical foreign matter (bark, bract, brown leaf, green leaf, hull, seed coat, seed, stem), and four types of non-botanical foreign matter (paper, twine, plastic bale packaging, plastic bag) were subjected to a fluorescence spectroscopy analysis to determine their optimal excitation and emission wavelength range. Matrix 3D scans were performed in the excitation range from 300 nm to 500 nm, and emission range from 320 nm to 700 nm, and the results indicated the photo-excitable fluorescence in the aforementioned excitation range for all the selected foreign matter categories. Consequently, the blue and the UV LEDs were selected as the excitation sources. The blue LED light provided optimal excitation light for bark, brown leaf, bract, green leaf, hull, and stem, while the UV LED light provided optimal excitation light for paper, plastic bag, plastic packaging, seed, seed coat, and twine.ConclusionsUV and blue light induces fluorescence in 12 types of botanical and non-botanical cotton foreign matter. An imaging apparatus with blue and UV light excitation sources, and a consumer grade SLR camera was successfully developed to capture and characterize fluorescent images of cotton foreign matter. Based on the results, fluorescent imaging could be a promising method for cotton foreign matter detection. Future studies will focus on the classification of cotton foreign matter categories and to further refine the image processing sequence.
| S-EPMC4413534 | biostudies-literature
Project description:The facemask is a device to protect yourself and others against pandemics, such as coronavirus disease 2019 (COVID-19), and adding a functional filter to the facemask could offer extra protection against infectious microbes (such as bacteria and viruses) to the wearer. Here, we designed and fabricated an always-on photocatalytic antibacterial facemask, which comprised a reusable polypropylene filter layer coated with the photocatalytic laminated ZnO/TiO2 bilayer and a separate UV-LEDs layer to supply UV whenever necessary. The fabricated photocatalytic filter was able to be directly inserted into the reusable facemask together with the UV-LEDs layer. This facemask could be used repeatedly and sustainably anytime and anywhere regardless of solar illumination. The photocatalytic filter exhibited an excellent photocatalytic antibacterial effect likely due to recombination suppression of electrons and holes of ZnO/TiO2 bilayer and wetting transition from hydrophilic to superhydrophilic state on the surface of the filter. Thanks to the kirigami pattern in both photocatalytic filter and UV-LEDs layer, full-face covering, breathability, flexibility, and the snug fit are believed to be improved. Although further in-depth studies are still needed and there is a long way to go, we expect our design idea on the facemask to be considered in various fields. Graphical abstract Image 1
| S-EPMC8828298 | biostudies-literature
Project description:To interrupt SARS-CoV-2 transmission chains, Ultraviolet-C (UVC) irradiation has emerged as a potential disinfection tool to aid in blocking the spread of coronaviruses. While conventional 254-nm UVC mercury lamps have been used for disinfection purposes, other UVC wavelengths have emerged as attractive alternatives but a direct comparison of these tools is lacking with the inherent mechanistic properties unclear. Our results using human coronaviruses, hCoV-229E and hCoV-OC43, have indicated that 277-nm UVC LED is most effective in viral inactivation, followed by 222-nm far UVC and 254-nm UVC mercury lamp. While UVC mercury lamp is more effective in degrading viral genomic content compared to 277-nm UVC LED, the latter results in a pronounced photo-degradation of spike proteins which potentially contributed to the higher efficacy of coronavirus inactivation. Hence, inactivation of coronaviruses by 277-nm UVC LED irradiation constitutes a more promising method for disinfection.
| S-EPMC9575548 | biostudies-literature
Project description:The problem of antimicrobial resistance (AMR) is not limited to the medical field but is also becoming prevalent on a global scale in the environmental field. Environmental water pollution caused by the discharge of wastewater into aquatic environments has caused concern in the context of the sustainable development of modern society. However, there have been few studies focused on the treatment of hospital wastewater, and the potential consequences of this remain unknown. This study evaluated the efficacy of the inactivation of antimicrobial-resistant bacteria (AMRB) and antimicrobial resistance genes (AMRGs) in model wastewater treatment plant (WWTP) wastewater and hospital effluent based on direct ultraviolet (UV) light irradiation provided by a conventional mercury lamp with a peak wavelength of 254 nm and an ultraviolet light-emitting diode (UV-LED) with a peak emission of 280 nm under test conditions in which the irradiance of both was adjusted to the same intensity. The overall results indicated that both UV- and UV-LED-mediated disinfection effectively inactivated the AMRB in both wastewater types (>99.9% after 1-3 min of UV and 3 min of UV-LED treatment). Additionally, AMRGs were also removed (0.2-1.4 log10 for UV 254 nm and 0.1-1.3 log10 for UV 280 nm), and notably, there was no statistically significant decrease (p < 0.05) in the AMRGs between the UV and UV-LED treatments. The results of this study highlight the importance of utilizing a local inactivation treatment directly for wastewater generated by a hospital prior to its flow into a WWTP as sewage. Although additional disinfection treatment at the WWTP is likely necessary to remove the entire quantity of AMRB and AMRGs, the present study contributes to a significant reduction in the loads of WWTP and urgent prevention of the spread of infectious diseases, thus alleviating the potential threat to the environment and human health risks associated with AMR problems.
| S-EPMC11350808 | biostudies-literature
Project description:The recent surge in the use of UV technology for personal protective equipment (PPE) has created a unique learning opportunity for the UV industry to deepen surface disinfection knowledge, especially on surfaces with complex geometries, such as the N95 filter facepiece respirators (FFR). The work outlined in this study addresses the interconnectedness of independent variables (e.g., UV Fluence, respirator material) that require consideration when assessing UV light efficacy for disinfecting respirators. Through electron microscopy and Fourier-transform infrared (FTIR) spectroscopy, we characterized respirator filter layers and revealed that polymer type affects disinfection efficacy. Specifically, FFR layers made from polypropylene (PP) (hydrophobic in nature) resulted in higher disinfection efficiency than layers composed of polyethylene terephthalate (PET-P) (hygroscopic in nature). An analysis of elastic band materials on the respirators indicated that silicone rubber-based bands achieved higher disinfection efficiency than PET-P bands and have a woven, fabric-like texture. While there is a strong desire to repurpose respirators, through this work we demonstrated that the design of an appropriate UV system is essential and that only respirators meeting specific design criteria may be reasonable for repurposing via UV disinfection.
| S-EPMC8319424 | biostudies-literature