Decontamination Efficiency of a DBD Lamp Containing an UV–C Emitting Phosphor

Abstract

Among different physical and chemical agents, the UV radiation appears to be an important route for inactivation of resistant microorganisms. The present study introduces a new mercury-free Dielectric Barrier Discharge (DBD) flat lamp, where the biocide action comes from the UV emission produced by rare-earth phosphor obtained by spray pyrolysis, following plasma excitation. In this study, the emission intensity of the prototype lamp is tuned by controlling gas pressure and electrical power, 500 mbar and 15 W, corresponding to optimal conditions. In order to characterize the prototype lamp, the energetic output, temperature increase following lamp ignition and ozone production of the source were measured. The bactericidal experiments carried out showed excellent results for several gram-positive and gram-negative bacterial strains, thus demonstrating the high decontamination efficiency of the DBD flat lamp. Finally, the study of the external morphology of the microorganisms after the exposure to the UV emission suggested that other mechanisms than the bacterial DNA damage could be involved in the inactivation process.

Origin of Blue-Green Emission in α-Zn2P2O7 and Local Structure of Ln3+ Ion in α-Zn2P2O7:Ln3+ (Ln = Sm, Eu): Time-Resolved Photoluminescence, EXAFS, and DFT Measurements

“…These materials need to have a sufficiently wide band gap, low phonon frequency, high thermochemical stability, easy availability, ease of synthesis, environmental benignness, etc. In fact, recently we have realized the potential of oxide-based hosts not only for lanthanide-doped luminescence but also as strong candidates to be used in future generations of rare-earth-free luminescence materials either due to the presence of defects in the band gap or because of intrinsic charge transfer transitions. − Pyrophosphate hosts belong to the category of ideal oxide-based hosts and have been explored extensively from a luminescence point of view in the field of lanthanide-activated phosphors, persistent phosphors, dosimetry, UV-emitting phosphors for biocidal applications, contrast agents for nuclear magnetic resonance imaging (MRI), − etc.…”

Parametric Studies of a Mercury-Free DBD Lamp

“…Solutions to reduce the high luminance could be dimming as in the Planon lamp [22] or using a diffuse surface as LED [23]. Another field of application for this lamp could be the decontamination of surfaces by changing the phosphor layer and the glass [24].…”

Bright UV-C Phosphors with Excellent Thermal Stability—Y1−xScxPO4 Solid Solutions

“…Compounds with bright luminescence in the UV spectral region attract attention due to their application in photocatalysis, photochemistry and medicine, for disinfection, as persistent phosphors and scintillating detectors [ 1 , 2 , 3 , 4 , 5 ]. Emission in the UV spectral region is an advantageous feature for application in scintillators because it corresponds to the area where solar blind light detectors can be used in the open mode without shielding from daylight radiation [ 2 ].…”