A ballast water treatment apparatus equipped with devices for injecting bromine salt and ozone includes a ballast pipe, a ballast pump, a bromine salt injection part and an ozone processor, wherein the injection part includes a bromine salt storage tank; a bromine salt transfer pipe connected to the ballast pipe for injecting bromine salt supplied from the bromine salt storage tank into the ballast pipe; and a bromine salt injection pump in the transfer pipe for pressurizing bromine salt to be injected into the ballast pipe, and the ozone processor includes an ozone injection device for supplying ozone to the ballast pipe; a mixer in the ballast pipe for mixing ozone supplied from the ozone injection device and seawater transferred into the ballast pipe; and an ozone transfer pipe connected to the mixer of the ballast pipe for injecting ozone supplied from the ozone injection device into the ballast pipe.

A water treatment system and a ballast water treatment method. A ballast water treatment system according to an embodiment of the present invention comprises: a first ballast water supply pipe for receiving a supply of ballast water from a first sea chest positioned in a non-explosion-proof area of a ship; an electrolytic bath for electrolyzing the ballast water supplied from the first ballast water supply pipe; a second ballast water supply pipe for receiving a supply of ballast water from a second sea chest, which is positioned in an explosion-proof area of the ship, and supplying the ballast water to a ballast tank of the ship; a filter provided to the second ballast water supply pipe so as to filter the ballast water passing through the second ballast water supply pipe; and a third ballast water supply pipe connected to the second ballast water supply pipe so as to supply the ballast water, which has been electrolyzed from the electrolytic bath, to the ballast water which has passed through the filter.

A ballast water treatment operating apparatus includes a ballast water treatment unit for performing a certain treatment of ballast water flowing in from the outside for a ballast operation or performing a certain treatment of ballast water discharged into the outside for a de-ballast operation; a positional information receiving unit for receiving positional information; a control unit for confirming a ship's position by using positional information received from the positional information receiving unit and then determining whether to operate the ballast water treatment unit during a ballast operation or during a de-ballast operation, thereby being capable of preventing an unnecessary energy consumption.

A device for filtering ballast water which performs filtering by installing a filter element having a conical shape in a concentric circle direction inside the device for filtering ballast water that accommodates a filter portion, and introducing ballast water from a lower end of the device for filtering and passing same through the filter element inside the device for filtering, and for discharging backwash water containing foreign substances that are inside a filter by ways of differential pressure, which is created by a driving portion communicating with a filter element by rotating an aspiration portion that is located on the lower end of the device for filtering. In particular, the present invention relates to a candle-type device for filtering ballast water, wherein the driving portion is positioned on a lower portion of the housing so that more filter elements can be accommodated inside the housing.

A system for withdrawing samples of fluids comprises a pitot tube assembly, a flow sensor to measure a flow rate of the sample, and a pump connected to the pitot tube assembly to withdraw a sample, wherein the system is configured to match a sample flow velocity to the flow velocity sensed by a flow sensor on a pitot wand. The pitot tube assembly comprises a housing with a sample outlet and a return sample inlet, an extendable/retractable pitot wand within the housing, wherein the pitot wand includes a passage extending the length thereof to transfer a sample from a pitot tube end to a sealed compartment in the housing connected to the sample outlet; wherein the return sample inlet is connected to a passage in the housing leading to an outlet from the housing, and a flow sensor on an end of the pitot wand.

A ballast water treatment device includes a filtration device and an irradiation device that irradiates, with ultraviolet rays, filtered water that has been filtered. The filtration device is a device that removes 99.999% or more of L-size organisms having a minimum part size of 50 μm or more, and 90% or more of S-size organisms having a minimum part size of 10 μm or more and less than 50 μm. The irradiation device is capable of sterilizing the filtered water at a flow rate of 250 m.sup.3/h and a power consumption of 13 kW to eliminate 90% of S-size organisms immediately after a sterilization treatment.

This method entails: collecting in advance untreated ballast water to which a chlorine-based active substance has not been added; measuring in advance the turbidity of the untreated ballast water; and adding a chlorine-based active substance with an adding amount determined on the basis of the turbidity. The amount of the chlorine-based active substance to be added is set according to the turbidity such that the concentration of total residual oxidants (TRO) is 0.5-3 mg/L (asCl.sub.2) when the ballast water is discharged.

A ballast water treatment system includes: a chemical agent container for containing a chemical agent for a ballast water treatment; a chemical liquid preparation tank having a tank main body for containing the chemical agent supplied from the chemical agent container and water for dissolving the chemical agent, and a mixture part for mixing the chemical agent with the water in the tank main body; a chemical liquid storage tank for storing the chemical liquid obtained by dissolving the chemical agent in the water in the chemical liquid preparation tank; and a chemical liquid supply part for supplying the chemical liquid stored in the chemical liquid storage tank into ballast water.

A ballast water treatment system includes an ultraviolet irradiation device which irradiates ballast water flowing through a treatment line (a pipe) with ultraviolet rays, and a control unit. The ultraviolet irradiation device includes a light source which emits ultraviolet rays, and an illuminance sensor sensing an illuminance of ultraviolet rays received by the ballast water. The control unit controls the ultraviolet irradiation device to maintain at a prescribed dose a dose calculated using an illuminance sensed by the illuminance sensor and a flow rate of ballast water which flows through the ultraviolet irradiation device. When the sensed dose cannot be maintained at the prescribed dose by controlling the ultraviolet irradiation device, the control unit reduces a treatment flow rate of the ballast water which flows through the treatment line.

A pleated filter includes a filter base having folds that repeatedly form mountains and valleys and having a cylindrical shape whose axial direction is a ridge line direction of the folds. The pleated filter includes, in a valley projecting to the inside of the cylindrical shape, a bonded reinforcing portion extending in the ridge line direction of the folds.