PROBLEM TO BE SOLVED: To provide a ship mounting a ballast water treatment system for always achieving a ballast water management reference which is specifically defined.SOLUTION: A ship 12 includes: a pump 28 that takes and drains ballast water; a water treatment device 14 that removes substances to be removed from the ballast water; a ballast tank 16 that stores the ballast water treated by the water treatment device; a valve 30 that is provided between the pump and the water treatment device; a monitoring device 18 that monitors the water quality of the ballast water at an inlet and an outlet of the water treatment device; and a control device 20 that monitors the water quality of the ballast water upon ballast water intake, controls the opening of the valve based on the result of monitoring, regulates the treated flow amount of the water treatment device, monitors the water quality of the ballast water upon ballast water drainage, drains the ballast water when the water quality based on the result of monitoring satisfies an allowable value, and controls to drain the ballast water after retreatment by the water treatment device when the water quality does not satisfies the allowable value.

Ballast water treatment system

PROBLEM TO BE SOLVED: To provide a flocculant injection control system which can further shorten time delay of feedback correction, is usable even for a case raw water has high turbidity and can compute a proper flocculant injection amount.SOLUTION: The flocculant injection control system for a water purification plant for removing flocs from raw water (flocculant-injected water) in which the flocs are formed by injecting a flocculant comprises a raw water sensor for measuring the water quantity and water quality of the raw water before the flocculant injection, a flocs classification device for classifying the flocculant-injected water sampled upstream of the outlet of a settling basin in accordance with the particle diameters of the flocs to obtain classified treated water; a classified treated water turbidity sensor for measuring turbidity of the classified treated water; a control means for determining the injection amount of the flocculant and having an injection ratio computing function for computing the injection ratio of the flocculant based on the water quality of the raw water and an injection ratio correcting function for computing the correction value of the injection ratio of the flocculant based on the turbidity of the raw water and the turbidity of the classified treated water and determining the injection amount of the flocculant; and a chemical injection means for controlling the chemical injection equipment based on the injection amount of the flocculant which the control means determines.

Flocculant injection control system

PROBLEM TO BE SOLVED: To provide compact equipment and a method for flocculation precipitation treatment which require a lower rate of injection of a coagulant than that of conventional equipment, permit high-speed treatment and have excellent concentrating and dehydrating properties of produced sludge SOLUTION: The equipment carries out flocculation precipitation treatment comprising adding a coagulant to raw water containing suspended matter to separate into coagulated floc and clear water through flocculation precipitation It has a flocculation vessel 10 stirring the raw water added with the coagulant to form coagulated floc and a precipitation vessel 12 which allows the flocculated water from the vessel 10 to flow in from its lower part, causes clear water to flow out from its upper part and separates coagulated flock through adsorption with the floc blanket layer formed within the vessel 12 In the vessel 12, stirring is carried out with a GT value, a product of the stirring intensity G, sec-1, and the residence time T, sec, of ≥200,000 COPYRIGHT: (C)2006,JPO&NCIPI

Equipment and method for flocculation precipitation treatment

PROBLEM TO BE SOLVED: To provide a flocculating, precipitating and filtering system capable of properly adjusting the injection rate of a flocculant, preventing excess chemicals from flowing in a filtering facility by carrying over from precipitation equipment, and preventing filtering blockage at the facility.SOLUTION: An injection rate of a flocculant to be injected in a chemicals injection facility 10, and the revolution of a slow agitator 31 in a slow agitation facility 30 are controlled by a suction filtration time ratio of a supernatant liquid obtained by injecting a flocculant in a test water directly obtained from a water treated by flocculation and precipitation and/or raw water, and then conducting a flocculation test.

Flocculating, precipitating and filtering system

PROBLEM TO BE SOLVED: To reduce a cost required for aggregation and agitation processing while controlling the water quality of treatment water at a target value.SOLUTION: A control device estimates the water quality of precipitation treatment water when carrying out rapid agitation processing by injecting a coagulant under a plurality of injection rate conditions; calculates an evaluation value by using an evaluation function including a cost for aggregation agitation processing and a deviation of an estimated value to a target value of the water quality of the precipitation treatment water as a parameter, about the plurality of injection rate conditions, by using the estimated water quality of the precipitation treatment water; decides an optimal injection rate condition of the coagulant on the basis of the evaluation value; and injects the coagulant into a coagulant injection device at the decided injection rate.

Water processing control method, and water processing control device

PURPOSE:To reduce delay time in regulating injection rate of flocculant by correcting feedback correction term at specified intervals based on the difference between predicted mean particle diameter determined from raw water and injection rate of flocculant and actually measured mean particle diameter of floc. CONSTITUTION:By detecting turbidity of raw water and turbidity at the outlet of a settling pond 4, flocculant injection rate is controlled using flocculant injection equation: D=A.TB +B (D: flocculant injection rate, TB: turbidity of raw water, A, n: coefficient, B: feedback correction term). ALT ratio (quantity of Al ion relative to turbidity of raw water) is determined from raw water and flocculant injection rate, whereby predicted mean particle diameter of floc is determined from ALT ratio thus obtained and equation relating to mean particle diameter of floc. Further, actually measured value of geometrical mean particle diameter of floc is obtained by image processing of floc measuring device 10 provided in a floc formation pond 3. By feeding back the difference between the predicted and measured mean particle diameter of floc at specified intervals, correction term B is corrected and injection rate of flocculant is regulated.

Method for regulating injection rate of flocculant by means of floc measuring device

PURPOSE:To accurately measure floc by catching floc by the submerged camera arranged in a floc forming basin and performing the image processing thereof by a computer to measure floc characteristic quantity and using the measured value as a feedback signal to control the formation of floc. CONSTITUTION:A flocculant is injected in raw water and floc is formed in a process wherein raw water flows in a floc forming basin 3. A submerged camera 11 is arranged in the floc forming basin and formed floc is caught as an image. The floc image caught by the submerged camera 11 is accessed between a host computer 20 and an image processor and floc characteristic quantity is measured by an image measuring part 19. The measured value is sent to a controller as a feedback signal and a flocculant injection amount is controlled on the basis of the signal. That is, the formation of floc is properly controlled.

Apparatus for controlling formation of floc

PURPOSE:To enable higher controlling accuracy by using a forecast runoff turbidity at a sediment pond as calculated from a very small amount of floc per unit capacity determined from image information at the rear of a floc formation pond as feedback control factor to control paddle revolutions to reduce control delay time. CONSTITUTION:A turbidimeter 6 is attached at an incoming water well 1 to measure turbidity of a stock and a turbidimeter 7 at a sediment pond 5 to measure a runoff turbidity. A coagulant injection controller 8 controls the injec tion of a coagulant. A paddle 4 is set at a floc formation pond 3 to stir up a water to be treated. A revolutions controller 10 controls a motor 9 for rotating the paddle. An under water camera 11 is attached at the final stage of the floc formation pond 3. A floc measuring device 12 determines an average parti cle size of floc and a very small amount of floc per unit capacity of the water to be treated based on image information from the camera 11 while determining a maximum floc particle size from an intensity of rotation of the paddle. The rotation intensity of the paddle is controlled based on these values to reduce paddle control delay time with a higher controlling accuracy.

Floc formation controller

PURPOSE:To enhance the accuracy of control and to shorten the delay time of control by introducing the average grain size of pulverized coal and the amt. of the pulverized coal per unit weight of treated water as feedback signals to an arithmetic processing section and controlling the amt. of the active carbon to be injected in accordance with the computed signals. CONSTITUTION:The amt. of the pulverized coat per unit weight is determined from the image information of a submersible camera 11 in a settling basin 4 and the predicted effluent turbidity in the settling basin 4 is calculated from the amt. of the pulverized powder. The amt. of the active carbon powder to be injected is controlled with the predicted effluent turbidity as a feedback control factor to enhance the control accuracy. The pulverized powder which cannot be removed in the inlet of the settling basin 4 in the stage of the end of the contact with the material desired to be removed and the active carbon powder is detected and the delay time of the feedback control is shortened. The criterion for the control of the injection rate of a flocculating agent is determined from the amt. of the pulverized powder and the predicted effluent turbidity. In addition, the finer segmenting of the criteria is possible by changing the differential spacing between the set value and the measured image value.

Controller for injection of active carbon to water treating device

PURPOSE:To make pre-processing at the time of binarizing unnecessary and to easily realize the recognition of whole flocs and the decision of an optimum threshold by using a parallel opposed type illuminator and arithmetic-operating the inflection point of luminance histogram within a display screen with the aid of a difference calculus. CONSTITUTION:A set of projectors 31 which are opposed and disposed in parallel, a black screen 32 arranged between the projectors 31, a camera 33 and an optical fiber 34 are provided. Then, these respective means are sunk in a forming pond and the projectors 31 light the floc existing in front of the screen 32 from both sides of the screen 32. Besides, the screen 32 is black and the projected floc is projected with the luminance of black or more. In this way, the pre-processing at the time of binarizing can be made unnecessary and the recognition of the whole flocs and the decision of the optimum threshold are easily realized.

Shimazaki Hiroshi

Papers

Method for regulating injection rate of flocculant by means of floc measuring device

Apparatus for controlling formation of floc

Floc formation controller

Controller for injection of active carbon to water treating device

System for monitoring floc