scholarly journals Study on the killing of oceanic harmful micro-organisms in ship's ballast water using oxygen active particles

2013 ◽  
Vol 418 ◽  
pp. 012111
Author(s):  
C Chen ◽  
X Y Meng ◽  
M D Bai ◽  
Y P Tian ◽  
Y Jing
Keyword(s):  
Ballast Water ◽  
Active Particles ◽  
Micro Organisms ◽  
Ship’S Ballast Water

Studies of the Effect of Hydroxyl Radicals on Photosynthesis Pigments of Phytoplankton in Ship's Ballast Water

2004 ◽  
Vol 7 (2) ◽  
Author(s):  
Zhitao Zhang ◽  
Mindong Bai ◽  
Xiyao Bai ◽  
Bo Yang ◽  
Mindi Bai ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Ballast Water ◽  
Experimental System ◽  
Marine Species ◽  
Pilot Scale ◽  
Invasive Marine Species ◽  
Ship’S Ballast Water

AbstractA pilot-scale system of 20 t/h for the treatment of ship’s ballast water and the setup of dissolved hydroxyl radical was introduced in this paper. With this experimental system, the kill efficiencies of bacteria, mono-algae, protozoan reach 100% within 2.67 s when dissolved OH· concentration is 0.6 mg/L. At the same time, the effect of hydroxyl radicals on the photosynthesis pigments of phytoplankton was done. The results indicate that the contents of chlorophyl-a, chlorophyl-b, chlorophyl-c and carotenoid are decreased to 35 ~ 64% within 8.0 s further to the lowest limit of test after 5 min. When dissolved OH· ratio concentration is 0.68 mg/L, the attenuation efficiencies of photosynthesis pigment are 100%. Therefore the invasive marine species can be killed in the process of the inputting and discharge ship’s ballast water.

scholarly journals Analysis of Ballast Water Treatment Technologies on Ships Operating in the Baltic Sea Region

2020 ◽  
Vol 8 (1) ◽  
pp. 15-20
Author(s):  
Renāte Kalniņa ◽  
Alise Romule
Keyword(s):  
Baltic Sea ◽  
Ballast Water ◽  
Aquatic Organisms ◽  
Water Control ◽  
The Baltic Sea ◽  
Baltic Sea Region ◽  
Treatment Technologies ◽  
Control Technologies ◽  
The Baltic ◽  
Ship’S Ballast Water

AbstractThe introduction of invasive aquatic species in new environments has been identified as one of the four biggest threats to the world's oceans causing serious threats and harm to both ecology and human health. There is a major exchange of ship’s ballast water over longer distances between continents and regional seas, and it has been known for decades that ballast water transfers organisms to new ecosystems, where the strongest, most aggressive and adaptable species can survive and become invasive under favourable conditions. The focus of the research is to study available ballast water control technologies to determine their suitability and effectiveness in the reduction of harmful aquatic organisms and compounds in the Baltic Sea.

Distribution of gyrotactic micro-organisms in complex three-dimensional flows. Part 1. Horizontal shear flow past a vertical circular cylinder

2018 ◽  
Vol 852 ◽  
pp. 358-397 ◽  
Author(s):  
L. Zeng ◽  
T. J. Pedley
Keyword(s):  
Circular Cylinder ◽  
Shear Flow ◽  
Vortex Shedding ◽  
Water Surface ◽  
Concentration Distribution ◽  
Three Dimensional ◽  
Swimming Velocity ◽  
Horizontal Shear ◽  
Active Particles ◽  
Micro Organisms

As a first step towards understanding the distribution of swimming micro-organisms in flowing shallow water containing vegetation, we formulate a continuum model for dilute suspensions in horizontal shear flow, with a maximum Reynolds number of 100, past a single, rigid, vertical, circular cylinder that extends from a flat horizontal bed and penetrates the free water surface. A numerical platform was developed to solve this problem, in four stages: first, a scheme for computation of the flow field; second, a solver for the Fokker–Planck equation governing the probability distribution of the swimming direction of gyrotactic cells under the combined action of gravity, ambient vorticity and rotational diffusion; third, the construction of a database for the mean swimming velocity and the translational diffusivity tensor as functions of the three vorticity components, using parameters appropriate for the swimming alga, Chlamydomonas nivalis; fourth, a solver for the three-dimensional concentration distribution of the gyrotactic micro-organisms. Upstream of the cylinder, the cells are confined to a vertical strip of width equal to the cylinder diameter, which enables us to visualise mixing in the wake. The flow downstream of the cylinder is divided into three zones: parallel vortex shedding in the top zone near the water surface, oblique vortex shedding in the middle zone and quasi-steady flow in the bottom zone. Secondary (vertical) flow occurs just upstream and downstream of the cylinder. Frequency spectra of the velocity components in the wake of the cylinder show two dominant frequencies of vortex shedding, in the parallel- and oblique-shedding zones respectively, together with a low frequency, equal to the difference between those two frequencies, that corresponds to a beating modulation. The concentration distribution is calculated for both active particles and passive, non-swimming, particles for comparison. The concentration distribution is very similar for both active and passive particles, except near the top surface, where upswimming causes the concentration of active particles to reach values greater than in the upstream strip, and in a thin boundary layer on the downstream surface of the cylinder, where a high concentration of active particles occurs as a result of radial swimming.

scholarly journals IMPACT OF SHIP'S BALLAST WATER ON INVASIVE SPECIES OCCURRENCE, AND AS A CONSEQUENCE ON ENVIRONMENTAL AND PUBLIC HEALTH: A SHORT REVIEW

2020 ◽  
Vol 36 (1) ◽  
pp. 18-21
Author(s):  
A. Kholdebarin ◽  
N. Mozaffari ◽  
V. Vambol ◽  
S. Vambol ◽  
N. Mozaffari
Keyword(s):  
Public Health ◽  
Invasive Species ◽  
Ballast Water ◽  
Water Pressure ◽  
Ecological Impacts ◽  
Nutrient Cycle ◽  
Species Occurrence ◽  
Study Results ◽  
The Impact ◽  
Ship’S Ballast Water

Water is one of the main ways of transportation. The reduction of water pressure on the ship hull, controlling ship submergence, compensate for the impact of losing weight from fuel or water consumption, help to the existence of lateral balance and stability are the factors that show all ships need ballasting. Ballast water contains a large number of organisms from different species, which are in different life stages (egg, Larvae, Cysts, Spores, or adult). These aquatic invasive species cause damage to fisheries, aquaculture, water supply system, industrial infrastructure, biodiversity, and habitat. The study aims to review open information sources and analyze them to identify the Impact of ship's ballast water on invasive species occurrence, and as a consequence on environmental and public health effects. The search for sources was carried out for the keywords «ballast water», «ecology», «environment», «public health» and «invasive species», as well as for various combinations of these words through the Google Scholar. Restrictions in the search for sources amounted to: since 2005 and in relevance. The features of one of the reasons for the spread of invasive species and negative environmental consequences for aqua systems and public health are studied. The study's practical value lies in the fact that the study results can be used to train workers from water transport and ensure the environmental safety of aqua systems. Predation, parasitism, competition, the introduction of new pathogens, genetic changes, habitat alterations, species shift, and loss of biodiversity are the most important ecological impacts. Exotic species, which are often brought with ballast water, cause change to ecosystem function by changing in a nutrient cycle and a decrease in water quality. It is established that some invasive species including Vibrio Cholera and Giardia duodenalis that are transported by ballast water also affect the public health by increasing the risk of pathogens and parasitism.

Naphthoquinones as broad spectrum biocides for treatment of ship's ballast water: Toxicity to phytoplankton and bacteria

2007 ◽  
Vol 41 (6) ◽  
pp. 1294-1302 ◽  
Author(s):  
D.A. Wright ◽  
R. Dawson ◽  
S.J. Cutler ◽  
H.G. Cutler ◽  
C.E. Orano-Dawson ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Ballast Water ◽  
Water Toxicity ◽  
Ship’S Ballast Water
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