scholarly journals Technology of purifying and disinfecting ballast water

Author(s):  
Valeriy Ivanovich Reshnyak ◽  
Alexander Ivanovich Kalyaush ◽  
Dmitry Igorevich Rochev

The paper considers the problem of transferring microorganisms with ballast water used in the ship operation. It is noted that the search for a solution to the above problem takes a significant amount of time and requires developing special purifying equipment for disinfecting ballast water. Currently, there are various plants ensuring the decreased number of microorganisms in the process of disinfection. There has been proposed a new technology for ballast water treatment and decontamination that involves depositing microorganisms, removing them from the total volume of ballast water followed by ozone treatment. Actually, the volume of water containing sediment and decontaminated with ozone is significantly less than the total volume of ballast water and makes up about 3-5% of it. Microorganisms depositing takes place due to coagulation and sedimentation. The diagram of the ballast water purification and disinfection technology has been presented. The basic circuit of the ballast water disinfection plant includes a ship's ballast tank, receiving pipeline, reagent tank, metering pump, coagulant, collector, bulkhead, contact column, ozone generator, dehydration device and ultraviolet lamps. The operating conditions of the ship plants have space and time limits. The above technological solutions infer carrying out some operations (coagulation, sedimentation) and disinfection by using the ultraviolet lamps inside the ballast tanks for saving space. The proposed technology can be applied both on board a ship and in the floating or onshore environmental protection equipment, for example, in the port facilities.

2019 ◽  
Vol 80 (12) ◽  
pp. 2310-2319 ◽  
Author(s):  
Prashant Dhanke ◽  
Sameer Wagh ◽  
Abhijeet Patil

Abstract Water generated from the fish processing industry is contaminated with organic matter. This organic matter present in wastewater increases the biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A new technology, hydrodynamic cavitation (HC) is used to deal with this wastewater produced in fish processing plants. The orifice plate is used in the HC reactor to generate a cavitation effect. The intensification of this technique was carried out with the help of hydrogen peroxide (H2O2) and TiO2. The treatment of this wastewater is reported in terms of percent degradation in BOD and COD and in biodegradability index (BI). Operating parameters like inlet pressure, pH, operating temperature and H2O2 doses were used to find the optimum condition. 15 g/L of H2O2 gave 69.5% reduction of COD in the 120 min of treatment that also increases BI value to 0.93 at inlet pressure 8 bar, Plate-5, temperature (30 °C), and pH 4. In the ultrasonic cavitation (UC) reactor, COD reduction is 68.7% without TiO2 and with TiO2 it is 71.2%. Also, this HC and UC reactor reduced CFU count to a great extent at the same operating conditions.


2006 ◽  
Vol 52 (12) ◽  
pp. 1756-1767 ◽  
Author(s):  
Jake C. Perrins ◽  
Jeffery R. Cordell ◽  
Nissa C. Ferm ◽  
Jaime L. Grocock ◽  
Russell P. Herwig

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 455
Author(s):  
Kevin Q. T. Luong ◽  
Yuanxun (Ethan) Wang

Mechanically driven magnetoelectric antennas are a promising new technology that enable a reduction in antenna size by many orders of magnitude, as compared to conventional antennas. The magnetoelastic coupling in these antennas, a phenomenon playing a direct role in determining performance, has been modeled using approaches that are severely lacking in both accuracy and tractability. In response to this problem, we take a physics-based approach to the analysis of magnetoelastic coupling. We find that certain directions of applied stress will maximize the coupling and we derive general expressions to quantify it. Our results are applied in comprehensive simulations that demonstrate the dynamic nature of the coupling as well as the impact of various operating conditions and material properties. Our work contributes analytical expressions and associated insight that can serve not only as guidelines for the design of mechanically driven magnetoelectric antennas, but also as stepping stones towards the development of more accurate models.


2021 ◽  
Vol 4 (3(60)) ◽  
pp. 6-8
Author(s):  
Iryna Koval

The object of research is the process of water disinfection at the influence of gas from bacteria of a particular genus with different amounts per unit volume of water. Due to the annual increase in the amount of pollutants in natural waters, new opportunities to improve microbiological indicators of water quality are being explored. There are many different ways to disinfect it, both physical and chemical. However, no single method has been found to purify aqueous media from microorganisms that would ensure their effective destruction. It is proposed to study the activity of specific microorganisms during the bubbling of inert gas through the aqueous medium. The microorganisms studied were rod-shaped sporogenic cells of Bacillus cereus bacteria type. The test gas was inert helium. The study used continuous gas bubbling throughout the process, which allowed to mix microbial water efficiently and prevent the formation of stagnant zones in the reaction medium. In particular, active gas mixing facilitates its access to each cell. The gas supply rate corresponded to 0.2 cm3/s, and its flow rate was 0.7 dm3 for one hour of bubbling through microbial water. The duration of the entire research process was 7200 s. The constant temperature of the microbial water (T=288±1 K) was maintained during the experiment by cooling the glass reactor with running water. An in-depth method of culturing bacterial cells was used. A decrease in the number of microorganisms was observed throughout the helium supply process, despite the different initial amounts in the water. The highest destruction degree of bacillus (77.06 %) was obtained at the lowest studied concentration in water (NM01=3.4·104 CFU/cm3). This is due to the fact that less microbial load provides better conditions for access of helium to the cell and their effective destruction. The proposed method of water purification allowed to achieve a sufficiently high degree of water disinfection from sporogenic rod-shaped bacteria after the action of helium alone. In particular, it has been experimentally proven that the efficiency of the water disinfection process depends on the concentration of microorganisms per unit volume of water. Due to the treatment of contaminated water with gas, it is possible to obtain high rates of its purification and the application of this method for practical purposes in water treatment technology.


Author(s):  
Nicholas J. Venero ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
David J. Miles

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel (UHSS) strip in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the design, manufacture and testing process for a self-propelled wrapping machine for in-field rehabilitation. The wrapping apparatus consists of several major components including an opening sufficiently wide to receive the pipe, a movement assembly, a winding head, a preforming device, an accumulator and an oscillating adhesive applicator. The wrapping apparatus uses the winding head to wrap the reinforcing steel strip around the pipe. The movement assembly uses a pair of tracks in contact with the pipe to drive the wrapping apparatus along which enables helical wrapping of the reinforcing strip material. The oscillating adhesive assembly applies structural adhesive to the pipe immediately before the strip is wound. The winding head, motive assembly and adhesive applicator are electronically synchronized to one another to enable precise control of pitch and adhesive volume. The paper also describes the field application of XHab including mobilization/demobilization of equipment and interaction with other rehabilitation equipment, as well as specific aspects such as initiation and termination of wrapping, protection of rehabilitated area and implementation of cathodic protection.


Author(s):  
Timothy K. Hight ◽  
Lee E. Hornberger ◽  
Elizabeth Lawrence ◽  
Matthew W. Gawlowski

Abstract Engineers need to absorb and learn large amounts of new technical information. Effective methods of receiving this information are needed. Hypermedia stacks are one emerging avenue for information transmittal. This paper discusses two programs that have been created to address two distinct requirements for information transmittal — description of new technology in an easily accessible form, and guiding novices in developing skills and gaining insights in solving a particular type of problem. The first program was developed using a HyperCard stack and a Macintosh computer and describes current techniques available for rapid prototyping. Professional engineers and engineering students are largely unaware of these technologies because information on the subject is new. The second program is being developed using ToolBook under Windows and deals with the problem of sizing an idler shaft under given loads and operating conditions. This is a standard type of problem that might be given in a junior level machine design course. It draws on knowledge from statics and strength of materials and so acts as a review of fundamentals as well as a test of deeper understanding. This second program is at an earlier stage of development.


2019 ◽  
Vol 283 ◽  
pp. 07011
Author(s):  
Didier Flotté ◽  
David Macel ◽  
Abd Ennour Bouzenad ◽  
Frédéric Navacchia

Monitoring the operation of the latest-generation nuclear reactor requires ultrasonic transducers able to operate at very high temperatures (> 600°C). To achieve this, CEA has requested from “Institut de Soudure” to help developing a new technology for these transducers compared to the one previously developed. This began with the development of a reliable assembly technique between a lithium niobate piezoelectric disc whose Curie temperature exceeds 1100°C and stainless steel discs. The chosen solution was to braze the niobate disc between two stainless steel discs. Parallel to this development, it was also necessary to develop a NDE procedure to verify the quality of the brazing assemblies. This development began with a simulation of immersion ultrasonic testing of the assemblies. The constraints were to be able to control the two brazed interfaces from the same access face, with the possibility of detecting and dimensioning defects with an equivalent diameter of 0.25 mm. This phase is important to define the optimal transducer with the associated operating conditions. The first assemblies validated the preliminary choices. To exploit the cartographies obtained, a signal processing procedure was developed. This enabled an automatic characterization of the indications observed. However, the analysis of the signals observed proved to be more complex than the one predicted by the simulation. Once the origin of the various observed signals was identified it was then possible to define windows allowing the construction of the cartographies to analyze. In case of a good quality assembly, it was possible to qualify the generated beam and to image it in the focal plane but with an observed signal having a very low damping. These first encouraging results, however, show that there is still some validation and development work to increase the sensitivity of the developed translator and its damping.


Author(s):  
Makoto Arai ◽  
Humberto S. Makiyama ◽  
Liang-Yee Cheng

In recent years, ballast water has been blamed for a variety of marine pollution problems, particularly for transporting harmful aquatic organisms from one part of the world to another and damaging the ecosystem of the new areas. A relatively simple mechanism to control this problem is to exchange ballast water on the high seas between ports in order to remove invasive species before the ship reaches its destination. However, some issues regarding ballast exchange on the open sea need to be addressed before this operation is introduced. One of them is the sloshing of the sea water in the ballast tank. In this paper, ballast water exchange on the open sea by means of the Sequential exchange method is simulated. Irregular seaways are generated from the ISSC spectrum, and the sloshing response of the water in the ballast tanks of a large merchant ship is numerically computed by using a finite difference code developed by the authors. The results showed that there is little possibility that severe sloshing presents a serious problem in regard to the ballast tank’s strength, especially in the case of a bulk carrier whose tanks are generally short in length, with sloshing anticipated only at the low water level.


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