Bioremediation of MP-polluted Waters Using Bacteria Bacillus licheniformis, Lysinibacillus massiliensis, and Mixed Culture of Bacillus sp. and Delftia acidovorans

Microplastic particles (MPs) are widely distributed pollutants in the environment. While a growing number of studies have shown that MPs are toxic to plant and animal life, systemic efforts to reduce their presence have been scarce. Low-density polyethylene (LDPE) and polystyrene (PS) are one of the most common among all plastic-forming MPs. In this study, pure bacterial strains, Bacillus licheniformis and Lysinibacillus massiliensis, and a mixed bacterial culture of Delftia acidovorans and Bacillus sp., were used for biodegradation of LDPE and PS microplastics. Biodegradation of MP-PS and MP-LDPE of particle size 300 – 500 μm was carried out under batch operating conditions at a temperature of 25 ± 2 °C, pH values of 7.15, and 160 rpm during 22 days. The obtained results showed that mixed bacterial cultures degraded MP-LDPE and MP-PS better than pure bacterial cultures, and the biodegradation efficiency was higher for MP-LDPE than for MP-PS, as indicated by greater reduction in peak intensity and spectral deformation, higher colony forming unit (CFU), and inorganic carbon (IC) values. This work is licensed under a Creative Commons Attribution 4.0 International License

Investigation of Solution-Processed Ultrathin Electron Injection Layers for Organic Light-Emitting Diodes

We study two types of water/alcohol-soluble aliphatic amines, polyethylenimine (PEI) and polyethyleni-mine-ethoxylated (PEIE), for their suitability as electron injection layers in solution-processed blue fluorescent organic light-emitting diodes (OLEDs). X-ray photoelectron spectroscopy is used to determine the nominal thickness of the polymer layers while ultraviolet photoelectron spectroscopy is carried out to determine the induced work-function change of the silver cathode. The determined work-function shifts are as high as 1.5 eV for PEI and 1.3 eV for PEIE. Furthermore, atomic force microscopy images reveal that homogeneous PEI and PEIE layers are present at nominal thicknesses of about 11 nm. Finally, we solution prepare blue emitting polymer-based OLEDs using PEI/PEIE in combination with Ag as cathode layers. Luminous efficiency reaches 3 and 2.2 cd A−1, whereas maximum luminance values are as high as 8000 and 3000 cd m−2for PEI and PEIE injection layers, respectively. The prepared devices show a comparable performance to Ca/Ag OLEDs and an improved shelf lifetime