A ballast water monitoring device and a method for detecting live phytoplankton are disclosed. The device comprises a chamber for receiving a sample, at least one light source to emit light towards the sample, a light detector to receive light from the sample and generate a light signal, and a controller. The controller is configured to control the at least one light source to emit a single pulse of light, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action if the calculated variable fluorescence is greater than the predetermined reference limit.

Techniques and systems for neutralizing discharge waters from ballast and/or cooling water biocidal treatment and disinfection systems are provided. The systems utilize, inter alia, oxidation reduction potential control to regulate the dechlorination of an electrocatalytically generated biocidal agent to allowable discharge levels in ship buoyancy systems and ship cooling water systems

A system for cleaning and sterilizing a water flow comprises a main treatment line with a pump to pump water from a water storage, a main filter, a sterilizing station and a system outlet. The main filter is provided with a first filter element and a backflush member to rinse the first filter element with backflush water. The secondary treatment line connects to an outlet of the backflush member, and has a backflush filter to remove silt from the backflush water. The main filter is designed such that the pressure difference over the first filter element is at least 0.1 bar (10 kPa) and the backflush filter is designed such that the pressure difference over the backflush filter element is less than 0.05 bar (5 kPa).

Embodiments of the invention relate to a ballast water treatment system and method onboard ships or sea-going vessels. The system includes a filtration system, a UV disinfection system and a biofouling control system, which is adapted to provide continuous control of multiplication of marine organisms even during an absence of a ballasting and a de-ballasting process.

A vessel has a compartment (34) for containing water, which compartment (34) has at least one opening (31) in a wall (30) thereof for allowing water to pass therethrough. The compartment (34) comprises an assembly (1) of a grating (10) and at least one anti-biofouling source (20), the grating (10) being positioned in the opening (31) for blocking items from passing through the opening (31) along with the water, and comprising a number of elements and spaces between the elements, and the anti-biofouling source (20) being configured to emit ultraviolet light during operation thereof for realizing anti-biofouling of at least a portion of the grating (10). At least one of the elements of the grating (10) is at least partially transparent to the ultraviolet light, enabling a design of the assembly (1) in which anti-biofouling of the entire grating (10) may be guaranteed.

An electrolytic treatment apparatus is provided. The electrolytic treatment apparatus includes: an electrolytic tank having a cathode and an anode: an injecting portion that injects a liquid into the electrolytic tank; at least one diaphragm that partitions an inner space of the electrolytic tank into a cathode-side region including the cathode and an anode-side region including the anode, and makes a liquid in the cathode-side region and a liquid in the anode-side region electrically connected; a cathode-side discharging portion that supplies, to an exhaust gas treatment apparatus, a cathode-side solution generated in the cathode-side region by electrolyzing the liquid; and an anode-side discharging portion that supplies, to a sterilizing apparatus, an anode-side solution generated in the anode-side region by electrolyzing the liquid.

A vessel has a compartment (34) for containing water, which compartment (34) has at least one opening (31) in a wall (30) thereof for allowing water to pass therethrough. The compartment (34) comprises an assembly (1) of a grating (10) and at least one anti-biofouling source (20), the grating (10) being positioned in the opening (31) for blocking items from passing through the opening (31) along with the water, and comprising a number of elements and spaces between the elements, and the anti-biofouling source (20) being configured to emit ultraviolet light during operation thereof for realizing anti-biofouling of at least a portion of the grating (10). At least one of the elements of the grating (10) is at least partially transparent to the ultraviolet light, enabling a design of the assembly (1) in which anti-biofouling of the entire grating (10) may be guaranteed.

Cell counting device A cell counting device and a method of using a cell counting device are disclosed. The cell counting device comprises a chamber for receiving a sample, at least one light source to emit light towards a section of the chamber. The section of the chamber comprises a sub-sample of the sample. The cell counting device also comprises a light detector to receive a light emitted from the section of the chamber and to generate an electronic signal associated with the received light, and a controller. The controller is configured to estimate the number of photoactive cells in the sample by calculating the distribution of variable fluorescence [F.sub.v] values of a predetermined number of sub-samples about the mean F.sub.v value.

A ballast water treatment device attached to a vessel provided with: a line (1) through which drawn treatment target water flows; and a ballast tank (5) connected to a downstream side of the line (1). The ballast water treatment device is provided with: a filter (3) which is disposed in the line (1) and which filters the treatment target water; and a controller (7). The controller (7) causes the treatment target water to be discharged outboard from an upstream side of the filter (3) in an early stage of drawing of the treatment target water, until water quality is stabilized, and, when the water quality of treatment target water has stabilized, causes the filter (3) to filter the treatment target water. Thus, ballast water filtering can be efficiently performed.

Provided is a multi-tube nozzle for use in eradicating harmful aquatic organisms, which physically kills harmful aquatic organisms while feeding water and thus allows intake water to be fed directly into a culture tank or a ballast tank without the need for a pretreatment tank, chemicals, neutralizers, etc. A multi-tube nozzle (A) for use in eradicating harmful aquatic organisms includes at least three nozzle tubes (1) that are provided adjacent to each other. The nozzle tubes (1) each includes: an inlet-side opening section (2) having an inner diameter that decreases from an inlet opening toward a throat section (3) located in the middle of the tube; an outlet-side opening section (4) having an inner diameter that increases from the throat section (3) toward an outlet opening; and the throat section (3) having a smallest inner diameter. The adjacent nozzle tubes (1) are spaced apart by a distance such that the adjacent inlet-side opening sections (2) overlap each other. A wall (5) of an overlapping portion (6) of the inlet-side opening sections (2) is cut in a U shape. An uncut portion (5a) between the adjacent U-shaped cut portions (5b) forms a sword-like pointed tip.