A method for inhibiting scale including inorganic cations, and an economically operable geothermal power generating device which can inhibit deposition of scale. The geothermal power generating device includes: an inorganic cation concentration measuring device for measuring the concentration of bivalent or more inorganic cations in geothermal water collected from a production well; a flowmeter for measuring the flow rate of the geothermal water collected from the production well; a heat removal unit for lowering the temperature of the geothermal water; a thermometer for measuring the temperature of the geothermal water after removing heat; a pH measuring device for measuring the pH of the geothermal water after removing heat; a calculation processing unit for calculating the additive amount of a scale inhibitor; and a control unit for adding the scale inhibitor to the geothermal water by the amount calculated by the calculation processing unit.

A method for inhibiting scale including inorganic cations, and an economically operable geothermal power generating device which can inhibit deposition of scale. The geothermal power generating device includes: an inorganic cation concentration measuring device for measuring the concentration of bivalent or more inorganic cations in geothermal water collected from a production well; a flowmeter for measuring the flow rate of the geothermal water collected from the production well; a heat removal unit for lowering the temperature of the geothermal water; a thermometer for measuring the temperature of the geothermal water after removing heat; a pH measuring device for measuring the pH of the geothermal water after removing heat; a calculation processing unit for calculating the additive amount of a scale inhibitor; and a control unit for adding the scale inhibitor to the geothermal water by the amount calculated by the calculation processing unit.

An apparatus for filtration has a feed of sludge, containing liquid, solids and gases fed into a tank, the tank containing at least one spinning separation filter comprising a filter cone set having a filter screen, and a barrier cone, arranged roughly in parallel, and defining a conical workspace between them, the conical workspace having a peripheral opening to the tank and a central opening communicating with the interiors of one or more hollow shafts supporting the barrier cone and the filter cone, the upper shaft supporting the barrier cone having an upper axial channel for the exit of gases, the lower shaft supporting the center of the filter cone having a lower axial channel for the exit of liquid or oil, motor means for producing rotation in said at least one spinning separation filter, and a filtrate liquid reservoir located underneath the filter cone for capturing the filtrate passing through the filter screen.

An apparatus for filtration has a feed of sludge, containing liquid, solids and gases fed into a tank, the tank containing at least one spinning separation filter comprising a filter cone set having a filter screen, and a barrier cone, arranged roughly in parallel, and defining a conical workspace between them, the conical workspace having a peripheral opening to the tank and a central opening communicating with the interiors of one or more hollow shafts supporting the barrier cone and the filter cone, the upper shaft supporting the barrier cone having an upper axial channel for the exit of gases, the lower shaft supporting the center of the filter cone having a lower axial channel for the exit of liquid or oil, motor means for producing rotation in said at least one spinning separation filter, and a filtrate liquid reservoir located underneath the filter cone for capturing the filtrate passing through the filter screen.

Provided are an apparatus for removing boron and a method for removing boron for reducing the boron concentration in water to be treated, and an apparatus and a method for producing pure water wherein the boron concentration is reduced. An apparatus for removing boron includes: a first electrodeionization device to which water to be treated is supplied; an ultraviolet oxidation device to which the water treated by the first electrodeionization device is supplied; an oxide removal device to which the water treated by the ultraviolet oxidation device is supplied; and a second electrodeionization device to which the water treated by the oxide removal device is supplied. A method for removing boron using the apparatus is provided. The oxide removal device is equipped with a platinum group metal catalyst, and the water that has been treated by the oxide removal device has a hydrogen peroxide concentration of less than 1 ppb.

A method for treating a urea aqueous solution includes a first stripping step of steam stripping an aqueous solution containing urea, ammonia and carbon dioxide at 0.2 to 0.6 MPaA in a first stripper to separate ammonia and carbon dioxide from this aqueous solution into a gas phase; a hydrolysis step of hydrolyzing urea in the solution obtained from the first stripping step at an LHSV of 10 to 20 h.sup.−1, at 1.1 to 3.1 MPaA and 180 to 230° C. in a catalytic hydrolyzer; and a second stripping step of steam stripping a liquid obtained in the hydrolysis step in a second stripper to separate ammonia and carbon dioxide from this liquid into a gas phase. The residual urea concentration can be reduced to 1 ppm or lower; the residual ammonia concentration can be decreased; LHSV can be increased; and an increase in apparatus size is minimized.

A method for treating a urea aqueous solution includes a first stripping step of steam stripping an aqueous solution containing urea, ammonia and carbon dioxide at 0.2 to 0.6 MPaA in a first stripper to separate ammonia and carbon dioxide from this aqueous solution into a gas phase; a hydrolysis step of hydrolyzing urea in the solution obtained from the first stripping step at an LHSV of 10 to 20 h.sup.−1, at 1.1 to 3.1 MPaA and 180 to 230° C. in a catalytic hydrolyzer; and a second stripping step of steam stripping a liquid obtained in the hydrolysis step in a second stripper to separate ammonia and carbon dioxide from this liquid into a gas phase. The residual urea concentration can be reduced to 1 ppm or lower; the residual ammonia concentration can be decreased; LHSV can be increased; and an increase in apparatus size is minimized.

A method including acidifying a solution including dissolved inorganic carbon; vacuum stripping a first amount of a carbon dioxide gas from the acidified solution; stripping a second amount of the carbon dioxide gas from the acidified solution; and collecting the first amount and the second amount of the carbon dioxide gas. A system including; a first desorption unit including a first input connected to a dissolved inorganic carbon solution source to and a second input coupled to a vacuum source; and a second desorption unit including a first input coupled to the solution output from the first desorption unit and a second input coupled to a sweep gas source.

A method of chemical extraction and power generator cooling includes receiving an aqueous solution with dissolved inorganic carbon. The method further includes extracting the dissolved inorganic carbon from the aqueous solution and collecting the dissolved inorganic carbon. The aqueous solution is then acidified and supplied to the power generator to cool the power generator.

A method of chemical extraction and power generator cooling includes receiving an aqueous solution with dissolved inorganic carbon. The method further includes extracting the dissolved inorganic carbon from the aqueous solution and collecting the dissolved inorganic carbon. The aqueous solution is then acidified and supplied to the power generator to cool the power generator.