Репозиторий Университета

© 2020 Cigarette butts (CBs) represent the most common, though poorly biodegradable, type of waste on Earth. Thrown on the soil surface, they can remain unchanged for years, poisoning surrounding ecosystems with toxins accumulated during the smoking process. However, there is practically no data on the effect of smoked CBs on soil biota or soil animals in particular, nor on the potential of edaphic fauna to facilitate their decomposition. One of the most promising agents among soil animals are earthworms, which are known to be beneficial in the processes of recalcitrant organic matter degradation and stimulation of microbial activity in detrital food webs. In a microcosm experiment with the sod podzolic soil, we aimed at testing the effect of the commonly cultured epigeic earthworm Eisenia fetida (Savigny 1826) on the biodegradation rate of CBs and the possible adverse effects of this waste on the species. The experiment had a full-factorial design with three categorical predictors: CB number (0, 1 and 3 per microcosm); smoking condition (smoked and unsmoked CBs) and two levels of earthworm amendment (0 and 4 per microcosm). During 70 days of the experiment, we did not observe any smoked CB-induced mortality of earthworms. The addition of E. fetida significantly increased the CB mass loss across all treatment combinations. Specifically, earthworms improved the decomposition rate from 30 to 36% (p < 0.05), on average. However, this improvement was mainly associated with CB paper wrapping consumption. The inhibition of CO2 emission in microcosms with CBs and earthworms suggested the direct consumption of this waste by E. fetida, rather than modulation of the degradation potential of a microbial community. E. fetida appears to thus be a moderately promising agent for CB biodegradation with the simultaneous reduction in carbon loss from soil through the microbial channel in the studied soil type. These results open perspectives for the further evaluation of the role of soil macroinvertebrates in recalcitrant organic waste management in general and CBs in particular. We demonstrated that earthworms can efficiently decompose smoked and unsmoked cigarette butts regardless of their toxic potential and simultaneously reduce associated microbial activity.

© 2020 Ozonation (OZ) is an important advanced oxidation process to purify water and wastewater. Because of the lower solubility and instability of ozone (O3), selective oxidation and dependence on pH value, the industrial applications of OZ have been hindered by the following disadvantages: incomplete removal of pollutants, lower mineralization efficiency and the formation of toxic by-products. Meanwhile, OZ seems to have higher processing costs than other technologies. To improve the treatment efficiency and O3 utilization, several combined processes, such as H2O2/O3, UV/O3, and Cavitation/O3, have been explored, while the combined method of ultrasonication (US) with OZ is a promising treatment technology with a complex physicochemical mechanism. In US alone, the sonolysis of water molecules can produce more powerful unselective oxidant hydroxyl radicals ([rad]OH), and directly cause the sonochemical pyrolysis of volatile pollutants. In US/OZ, US can promote the mass transfer of O3, and also drive the chemical conversion of O3 to enhance the formation of [rad]OH. Various layouts of US/OZ devices and the interactive effects of US/OZ (synergism or antagonism) on the degradation of various organics are illustrated in this review. The main factors, including US frequency, pH value, and radical scavengers, significantly affect the mass transfer and decomposition of O3, the formation of [rad]OH and H2O2, the degradation rates of organics and the removal efficiencies of COD and TOC (mineralization). As a result, US can significantly increase the yield of [rad]OH, thereby improving the degradation efficiency and mineralization of refractory organics. However, US also enhances the decomposition of ozone, thereby reducing the concentration of O3 in water and impairing the efficiency of selective oxidation with O3 molecules.

© 2020 Elsevier B.V. The development of a highly efficient and rapid method for the accurate preparation of photocatalysts with novel morphologies is a hot research topic. The different morphologies of BiVO4 was prepared using surfactants-assisted microwave method, and demonstrated irregular (no surfactant), octahedral (sodium dodecyl benzene sulfonate), olive-like (polyvinylpyrrolidone) and hollow structures (ethylenediaminetetraacetic acid), respectively. The BiVO4-CdS were synthesized using the chemical-bath-deposition method with different morphologies of BiVO4 as the substrates. The hollow structure of BiVO4 displayed the highest photocatalytic performance. Moreover, the photodegradation rates of the hollow structure BiVO4-CdS on tetracycline hydrochloride and ciprofloxacin were about 1.8 and 1.5 times higher than the corresponding BiVO4, indicating that the Z-scheme heterojunction can improve the photogenerated electron pairs separation efficiency. Furthermore, the regulation mechanism of morphology and energy-band position, as produced using the surfactants, has also been thoroughly investigated in this work, which provides a novel insight into the efficient and rapid preparation of photocatalysts with special morphology and high performance.

© 2019 Elsevier B.V. Submicrocapsules were prepared from diethylaminoethyl dextran (DEAE-D), xanthan gum (XG) and bovine serum albumin (BSA) on oil cores by ultrasonic treatment. These capsules were modified with poly-L-lysine (PLL) via electrostatic adsorption. The behavior of the capsules was investigated at an air–water interface after their introduction into an aqueous subphase. The interaction of the capsules with 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer formed on the water surface (model cellular membrane) was studied both upon their introduction under the condensed monolayer and with the use of a dilute colloidal solution of the capsules as a subphase. Biodegradation of the proteinaceous capsules with subsequent oil-core release was demonstrated by influence of pronase. The Langmuir lipid monolayer was found to be a good model for investigation of drug release from the capsules in the presence of the cellular membrane.