Abstract: The purpose is to provide a pure water production method and apparatus, which make it possible to prevent the increase in an ion load during a pure water production process, improve the efficiency of a biological treatment and reduce the generation amount of pulverized coal in a method for treating oxidation-treated water in which urea is oxidized and decomposed with a hypohalous acid with biological activated carbon. Provided is a pure water production method including: for adding a hypohalous acid to urea-containing water of interest and performing an oxidation treatment of the urea in an oxidation treatment apparatus; and measuring the concentration of residual chlorine in the oxidation-treated water, then adding hydrogen peroxide to the oxidation-treated water depending on the measured concentration of the residual chlorine, and then performing a biological treatment of the hydrogen peroxide-added water with biological activated carbon in a biological treatment apparatus.

Abstract: An apparatus for producing pure water has: biological treatment means for biological treatment of water to be treated that contains an organic material; means for adding hypohalogous acid that is positioned downstream of biological treatment means and that adds hypohalogous acid to the water to be treated after the biological treatment is carried out; and ultraviolet ray radiating apparatus that is positioned downstream of means for adding hypohalogous acid and that radiates ultraviolet rays to the water to be treated to which the hypohalogous acid has been added.

Abstract: A sheet space-detecting device detects a space between a rear end of a preceding first fiber reinforced plastic sheet and a front end of a following second fiber reinforced plastic sheet in a conveyance path for fiber reinforced plastic sheets and includes: a light-detecting sensor that projects detection light on an area including the rear end of the first fiber reinforced plastic sheet, the front end of the second fiber reinforced plastic sheet, and a reference surface exposed from the space and receives reflected light thereof; and a spacer that supports the rear end of the first fiber reinforced plastic sheet and the front end of the second fiber reinforced plastic sheet in a state where the rear end and the front end are separated from the reference surface, in an area including at least a light-projected area on which the detection light is projected.

Abstract: Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m3-carrier·d) or greater.

Abstract: Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m3-carrier·d) or greater.

Abstract: A sheet space-detecting device detects a space between a rear end of a preceding first fiber reinforced plastic sheet and a front end of a following second fiber reinforced plastic sheet in a conveyance path for fiber reinforced plastic sheets and includes: a light-detecting sensor that projects detection light on an area including the rear end of the first fiber reinforced plastic sheet, the front end of the second fiber reinforced plastic sheet, and a reference surface exposed from the space and receives reflected light thereof; and a spacer that supports the rear end of the first fiber reinforced plastic sheet and the front end of the second fiber reinforced plastic sheet in a state where the rear end and the front end are separated from the reference surface, in an area including at least a light-projected area on which the detection light is projected.