Display omitted
•Water disinfection by simultaneous treatment with hydrodynamic cavitation and plasma discharge.•Decomposition of organic pollutants in water under hydrodynamic cavitation and ...plasma.•Easily scalable hybrid technology combining cavitation and plasma.•Intense generation of radicals, UV light, shock waves and charged particles.•Prolonged oxidation takes place in the solution/suspension after the end of the treatment.
Over the last two decades, the scientific community and industry have made huge efforts to develop environmental protection technologies. In particular, the scarcity of drinking water has prompted the investigation of several physico-chemical treatments, and synergistic effects have been observed in hyphenated techniques. Herein, we report the first example of water treatment under simultaneous hydrodynamic cavitation and plasma discharge with the intense generation of radicals, UV light, shock waves and charged particles. This highly reactive environment is well suited to the bulk treatment of polluted water (i.e. E. coli disinfection and organic pollutant degradation). We have developed a new prototype and have efficiently applied this hybrid technology to water disinfection and the complete degradation of methanol in water with the aim of demonstrating its scalability. We have analyzed the mechanisms of water disinfection under the abovementioned conditions and verified them by measuring cavitation noise spectra and plasma emission spectra. We have also used the degradation of textile dyes and methanol solutions as an indicator for the formation of radicals.
•The effect of ultrasound on viscosity of oil in well conditions was investigated.•A long lasting decrease in viscosity can be obtained only by sonochemical treatment.•The use of ultrasound may ...facilitate the production of viscous hydrocarbons.
Reduction of oil viscosity is of great importance for the petroleum industry since it contributes a lot to the facilitation of pipeline transportation of oil. This study analyzes the capability of acoustic waves to decrease the viscosity of oil during its commercial production. Three types of equipment were tested: an ultrasonic emitter that is located directly in the well and affects oil during its production and two types of acoustic machines to be located at the wellhead and perform acoustic treatment after oil extraction: a setup for ultrasonic hydrodynamic treatment and a flow-through ultrasonic reactor. In our case, the two acoustic machines were rebuilt and tested in the laboratory. The viscosity of oil was measured before and after both types of acoustic treatment; and 2, 24 and 48h after ultrasonic treatment and 1 and 4h after hydrodynamic treatment in order to estimate the constancy of viscosity reduction. The viscosity reduction achieved by acoustic waves was compared to the viscosity reduction achieved by acoustic waves jointly with solvents. It was shown, that regardless of the form of powerful acoustic impact, a long lasting decrease in viscosity can be obtained only if sonochemical treatment is used. Using sonochemical treatment based on ultrasonic hydrodynamic treatment a viscosity reduction by 72,46% was achieved. However, the reduction in viscosity by 16%, which was demonstrated using the ultrasonic downhole tool in the well without addition of chemicals, is high enough to facilitate the production of viscous hydrocarbons.
•We studied the sol-gel method for the titanium dioxide nanoparticles synthesis from titanyl sulphate.•We studied the synthesis of titanium dioxide and zinc oxide nanoparticles via sol-gel ...method.•The nanoparticles were synthesized near textile fibers and deposited on them in the same process via ultrasound.•Coated fabrics showed a suppression level of E. coli of more than 99.99% and the antibacterial activity of more than 1.8.•Such textiles can be used to prevent the spread of the nosocomial and other infections.
To prevent possible spread of nosocomial infections – HAI (Healthcare Acquired Infections) in healthcare facilities, Antibacterial textiles are developed. This carried out study has been conducted to assess the feasibility of the method of obtaining antibacterial coatings on textile materials. Specifically, the sol-gel method for synthesis of titanium dioxide nanoparticles in combination with zinc oxide nanoparticles from titanyl sulphate and zinc nitrate hexahydrate has been investigated.
During the synthesis of titanium dioxide nanoparticles in combination with the zinc oxide nanoparticles, the coated textile material showed stable antibacterial properties with a suppression level ofEscherichia coliof more than 99.99%. The method has been tested on a semi-industrial scale in roll-to-roll experimentby applying homogenous coatings at a speed of 1,5 m per minute.
This paper reports the results of the large-scale field testing of composite materials with antibacterial properties in a tropical climate. The composite materials, based on a cotton fabric with a ...coating of metal oxide nanoparticles (TiO2 and/or ZnO), were produced using high-power ultrasonic treatment. The antibacterial properties of the materials were studied in laboratory tests on solid and liquid nutrient media using bacteria of different taxonomic groups (Escherichia coli, Chromobacterium violaceum, Pseudomonas chlororaphis). On solid media, the coatings were able to achieve a >50% decrease in the number of bacteria. The field tests were carried out in a tropical climate, at the Climate test station “Hoa Lac” (Hanoi city, Vietnam). The composite materials demonstrated long-term antibacterial activity in the tropical climate: the number of microorganisms remained within the range of 1–3% in comparison with the control sample for the duration of the experiment (3 months). Ten of the microorganisms that most frequently occurred on the surface of the coated textiles were identified. The bacteria were harmless, while the fungi were pathogenic and contributed to fabric deterioration. Tensile strength deterioration was also studied, with the fabrics coated with metal oxides demonstrating a better preservation of their mechanical characteristics over time, (there was a 42% tensile strength decrease for the reference non-coated sample and a 21% decrease for the sample with a ZnO + CTAB coating).
•A sonochemical method is developed to enhance oil recovery from horizontal oil wells.•Ultrasound can enhance the effect of chemicals used to improve the performance of wells.•The method increases ...the permeability of the wellbore perforation zone and reduces blockages.•Field tests of the sonochemical method of EOR in vertical and horizontal wells have shown a significant improvement in oil production.
Oil production from wells reduces with time and the well becomes uneconomic unless enhanced oil recovery (EOR) methods are applied. There are a number of methods currently available and each has specific advantages and disadvantages depending on conditions. Currently there is a big demand for new or improved technologies in this field, the hope is that these might also be applicable to wells which have already been the subject of EOR. The sonochemical method of EOR is one of the most promising methods and is important in that it can also be applied for the treatment of horizontal wells. The present article reports the theoretical background of the developed sonochemical technology for EOR in horizontal wells; describes the requirements to the equipment needed to embody the technology. The results of the first field tests of the technology are reported.
•A down hole method for ultrasonic treatment is developed to enhance oil recovery on failing oil wells.•The method increases the permeability of the bottom hole zone and reduces blockages.•The method ...is simple, environmentally safe and is successful in up to 85% of cases.•The effect due to ultrasonic treatment lasts for 3–12months.
A new method for the ultrasonic enhancement of oil recovery from failing wells is described. The technology involves lowering a source of power ultrasound to the bottom of the well either for a short treatment before removal or as a permanent placement for intermittent use. In wells where the permeability is above 20mD and the porosity is greater than 15% ultrasonic treatment can increase oil production by up to 50% and in some cases even more. For wells of lower permeability and porosity ultrasonic treatment alone is less successful but high production rates can be achieved when ultrasound is applied in conjunction with chemicals. An average productivity increase of nearly 3 fold can be achieved for this type of production well using the combined ultrasound with chemical treatment technology.
Flexible materials, such as fabric, paper and plastic, with nanoscale particles that possess antimicrobial properties have a significant potential for the use in the healthcare sector and many other ...areas. The development of new antimicrobial coating formulations is an urgent topic, as such materials could reduce the risk of infection in hospitals and everyday life. To select the optimal composition, a comprehensive analysis that takes into account all the advantages and disadvantages in each specific case must be performed. In this study, we obtained an antimicrobial textile with a 100% suppression of E. coli on its surface. These CeO2 nanocoatings exhibit low toxicity, are easy to manufacture and have a high level of antimicrobial properties even at very low CeO2 concentrations. High-power ultrasonic treatment was used to coat the surface of cotton fabric with CeO2 nanoparticles.
•The use of 3 different types of waveguide systems for activation of ASFC reagents was investigated.•Ultrasound enables to reactivate the alumosilicic flocculant-coagulant.•In scaled up reactors the ...choice of the equipment type affects the stability of the achieved effect.
Acoustic fields formed during operation of ultrasonic reactors with waveguides of following types: rod-type, cylindrical with rectangular protrusions and tubular were calculated and measured. The influence of distribution of acoustic fields arising from the operation of waveguide systems of three different types on the efficiency of ultrasonic activation of alumosilicic flocculant-coagulant and magnetite intended for water purification was investigated. It was shown that regardless of the equipment used on an industrial scale it is possible to reactivate the alumosilicic flocculant-coagulant even after the shelf life period of it passed, however in case of activation of magnetite the use of a bigger reactor in inefficient.
In case of industrial scale processes, the choice of the correct reactor design is of significant importance, since it allows to reduce the required processing time, and, as a result, the energy consumption of the processes. The advantages of tubular waveguide systems include the possibility of processing large volumes of liquid. The high efficiency and uniformity of the excited ultrasonic fields can lead to reduction of operating costs. In case of smaller flows, the waveguide system with rectangular protrusions allowed to obtain better results.
Our work illustrates the dependence of the success of a specific method on the choice of the waveguide and the size of the reactor during upscale.
•The combined effect of shockwaves and ultrasound on water wells was investigated.•The use of the combined method is much more effective than ultrasound alone.•The production of the treated well ...increased by two times.
The regeneration of water wells is an urgent problem nowadays, when drilling of new wells becomes more and more expensive. Formation damage leads to a reduction of the formation's permeability and/or pore volume which in turn inhibits the ability of the water to flow from the reservoir formation into the wellbore. A new technology that uses high-power ultrasound to remove formation damage of water wells has been developed. The effectiveness of regeneration of wells can be enhanced if ultrasound and shockwaves are used during the same treatment. It was shown by computer modelling, that the two methods have different depths of impact. Whereas the ultrasonic method has a strong impact on the area of the filter tube, the impact of the shock waves is focused on the gavel pack, the wall of the well and the adjacent aquifer. A shockwave treatment, which is normally more effective due to larger impact zone, needs to be followed by ultrasonic treatment in order to facilitate the removal of the detached deposits. These theoretical assumptions were confirmed by field tests on two wells. The use of the method leaded to an increase of the production by 40% and 109% respectively.
A method for the production of antibacterial ZnO nanoparticles has been developed. The technique combines passing an electric current with simultaneous application of ultrasonic waves. By using ...high-power ultrasound a cavitation zone is created between two zinc electrodes. This leads to the possibility to create a spatial electrical discharge in water. Creation of such discharge leads to the depletion of the electrodes and the formation of ZnO nanoparticles, which demonstrate antibacterial properties. At the end of this reaction the suspension of ZnO nanoparticles is transported to a specially developed ultrasonic reactor, in which the nanoparticles are deposited on the textile. The nanoparticles are embedded into the fibres by the cavitation jets, which are formed by asymmetrically collapsing bubbles in the presence of a solid surface and are directed towards the surface of textile at very high velocities. Fabrics coated with ZnO nanoparticles by using the developed method showed good antibacterial activity against E. coli.
PDF
