Papers by Keyword: Ballast Water

Abstract: In light of urgent requirement of onboard ballast water treatment, a novel wall-flow structure porous ceramic filter (PCF) has been applied with combination of UV light in our laboratory works. According to the strict criteria of International Maritime Organization (IMO) on ballast water treatment, removal efficiencies on indicator planktons should be almost 100% even at high initial densities. However, the treatment efficiencies of PCF may be greatly affected by operational conditions of the system. Hence response surface methodology (RSM) was used to evaluate the significance of the operational factors on algal removal efficiencies. Based on our previous works, flow rate, algal density and algal size were considered as three key conditional factors during PCF treatment. These three individual factors and interactive effects between each two facts were studied statistically by Minitab 15. Also, experimental studies were arranged according to full factorial design of a 6L PCF on simulated ballast water treatment at different flow rates, algal densities and algal sizes. By computational prediction and mathematical analysis, the operational conditions were optimized with first order derivation of predicted model. And by doing so, the utmost optimization was estimated to achieve higher performance of PCF system.

Abstract: Invasive aquatic species discharged through ship ballast water is one of the most serious problems posed nowadays in the marine environment. The effect of inactivation of phytoplankton by pulsed electric field and thermal treatment was studied. Effect factors such as pulsed voltage, electrode gap, pulse width and preheating temperature were explored, and its mechanism of inactivation was analyzed. The combined effect of mild thermal and PEF treatments was shown to give more effective damage of phytoplankton than application of PEF treatment alone. The untreated ballast water sample pretreated at moderate temperature (323 K) and moderate PEF (E ≈10kV/cm) showed a noticeable enhancing of inactivation.

Abstract: Flocculation process is a method of ballast water treatment process which can satisfy the security, effective, environmental protection, operation and economic request , on the treatment of ballast water has been studied widely at home and abroad .The paper summarizes the flocculation process application treatment about ballast water of ship, introduced the affecting flocculation process factors , and discussed the application prospect of flocculation technology in ballast water treatment application field .

Abstract: In this research, the effect of modified bentonite on removing harmful organisms in ballast water was discussed using HDTMA⁺ modified bentonite as flocculating material, and Alexandrium tamarense, Nitzchia closterium, and Photobacterium phosphoreum as the objects of harmful organisms, and also through an observation of the reaction mechanism between HDTMA⁺ and bentonite with Fourier transform infrared spectroscopy (FTIR). The result showed that there was an effective combination of HDTMA⁺ with bentonite, and the modified organic bentonite possessed a powerful ability to remove harmful organisms. The removal rate against Alexandrium tamarense within 24h was greater than 85% if the dosage of the organic bentonite was 0.03 g/L; the removal rate against Nitzchia closterium was approximate to 80% if the dosage was 0.06 g/L; the luminous intensity could not be displayed by luminescent bacteria under the condition of concentration 0.30 g/L, and also the original soil with modification did not shown a significant removal effect under the same dosage. Therefore, it was concluded that the conditions such as aging time, organic bentonite’s particle size, and HDTMA⁺ dosage were the important factors affecting the harmful biological removal efficiency.

Abstract: UVA is seldom applied in UV inactivation or disinfection, however, it may be more suitable for underwater photo-catalysis treatment. Since the wavelength of UVA is longer than UVC, the former has higher transmission ability and encounter less disturbance of suspending substances in water. Also, the exciting wavelength of UVA is between 365nm and 413nm which coincides with the wavelength of UVA. Hence, the spatial distribution of UVA radiation is studied for a 15W UVA lamp. The decaying tendencies of UVA radiation intensity were probed over horizontal and vertical distance, behind large amounts of experimental data. Optimal radiation conditions plan to be detected based on the research to guide the UVA treatment.

Abstract: To eliminate the introduction of invasive marine species and the disadvantages of ballast water (BW) treatment systems a new concept in ship design was developed to be alternative of ballast water system. Non-Ballast ships were rarely mentioned in China even they were studied widely worldwide. In this paper, the different types of non-ballast water ship were reviewed, to be classified in order to facilitate the study of such types of vessels and serve as a base for the development.

Abstract: A UV ballast water treatment system was built in this paper. Nitzschiaclosteriumminutissima, Dunaliellasalina and Escherichia coli were selected as the test organisms to run the tests. The test results show that the inactivation ratio for the Escherichia colican close to 100%, when using 5UV lamps and the circulation volume was 5m³/h. While the inactivation ratio for the Nitzschiaclosteriumminutissima and Dunaliellasalina were 86.67% and 82.10%respectively. The investigation provides a better understanding of the UV ballast water treatment further.

Abstract: Biological invasions caused by Ballast water is always one of the diffcult problems of marine environmental protection, and the technology of ballast water treatment is an effective way to solve biological invasion. This article introduce many equipments of ballast water treatment, introduce physical ballast water treatment, chemical treatment and comprehensive treatment, then describes the advantages and disadvantages of these metheods.

Abstract: To solve the problem of high-salt ballast wastewater treatment, biological contact oxidation process by combined packing used to simulate the experimental study. When dissolved oxygen is 5 to 6, water temperature is 18 ~ 20 °C, pH is 7~8 and hydraulic retention time is 48h, the Influence of salinity dips and swells process on sludge treatment system and its effects were investigated. The results showed that salinity shock loads on the system less affected COD removal, after 3-5 days short adaptability run, the system became able to restore effluent water stability. The influence of Salinity swells process on AOB, NOB and denitrifying bacteria was greater than a dip .Salinity plunged produced smaller impact on the total nitrogen removal, while in the salinity swells TN removal reduced from 70.7% to 42%.

Abstract: Invasive aquatic species has been considered one of the greatest threats to the worlds oceans and marine ecological system. A novel of ships ballast water treatment based on ion exchange membrane electrolysis system to deal with algae has been proved. In this paper, an optimized treatment for inactivating algae is proposed based on the developed ballast water treatment system. In this optimized method, different experimental conditions are studied, which contain the injection times and small injection dose of anodic electrolytic products. The contrast experiments were conducted, the results show that the lethal time and available chlorine dose can respectively save up to 66.67% and 50% under the optimized method. The results show that the proposed have the more efficient kill ability for the algae life.