Abstract: A casing that squeezes sludge floc at one end portion, a screw shaft, a first screw blade spirally provided on an outer peripheral surface of the screw shaft, and a second screw blade provided side by side along a longitudinal direction of the screw shaft with the first screw blade with a predetermined interval from the first screw blade, are included. In the casing, a concentration zone and a separated liquid zone, which are substantially divided from each other by the first screw blade and the second screw blade, are formed. By rotation of the screw shaft, the sludge floc is squeezed in the concentration zone to be separated into sludge and separated liquid, and the separated liquid is moved rearward in the separated liquid zone to be discharged, while the sludge is discharged outside.

Abstract: A measuring method of bromate ion concentration includes a first fluorescence intensity measuring process including a process of passing hydrochloric acid through an anion exchanger to elute bromate ions adsorbed to the anion exchanger into the hydrochloric acid and a process of measuring the fluorescence intensity of the hydrochloric acid passed through the anion exchanger, a second fluorescence intensity measuring process including a process of passing a hydrochloric acid solution containing a fluorescent substance whose fluorescence intensity changes due to coexistence of bromate ions through an anion exchanger to elute bromate ions adsorbed to the anion exchanger into the hydrochloric acid solution and a process of measuring the fluorescence intensity of the hydrochloric acid solution passed through the anion exchanger, and a calculation process determining the bromate ion concentration in the water sample by using the difference between the fluorescence intensities of the hydrochloric acid solution and t

Abstract: A casing that squeezes sludge floc at one end portion, a screw shaft, a first screw blade spirally provided on an outer peripheral surface of the screw shaft, and a second screw blade provided side by side along a longitudinal direction of the screw shaft with the first screw blade with a predetermined interval from the first screw blade, are included. In the casing, a concentration zone and a separated liquid zone, which are substantially divided from each other by the first screw blade and the second screw blade, are formed. By rotation of the screw shaft, the sludge floc is squeezed in the concentration zone to be separated into sludge and separated liquid, and the separated liquid is moved rearward in the separated liquid zone to be discharged, while the sludge is discharged outside.

Abstract: A distributor pipe includes: a main pipe including a cylindrical part; and a plurality of branch pipes communicating with the main pipe and arranged, on a cylindrical curved surface of the main pipe, side by side along a longitudinal direction of the main pipe. A pipe diameter ratio D1/D0 of a pipe diameter D1 of the branch pipe to a pipe diameter D0 of the main pipe is greater than 0.2 and less than 0.8, and the plurality of branch pipes are arranged according to: respective effluent flow ratios, at a time a liquid flows into the main pipe in a predetermined flow velocity range, determined in accordance with respective arrangement orders of the plurality of branch pipes along a direction in which the liquid flows and along the longitudinal direction of the main pipe; and respective areas of circular or hollow-circular sections allotted to the plurality of branch pipes.

Abstract: A wastewater treatment apparatus includes: an air diffusing unit that supplies gas to nitrogen-containing water, so that ammonia contained in the nitrogen-containing water is nitrified to nitrate according to a flow of the water, and each desired proportion of the nitrate is denitrified at each position along the flow direction; a denitrification confirming unit provided at a halfway position between an upstream-side denitrification zone for obtaining a requisite minimum denitrified nitrogen amount and a downstream-side nitrification zone for obtaining ultimately required nitrified water quality, which follows the upstream-side denitrification zone on a downstream side thereof; and a gas supply-amount control unit that controls a gas supply amount from the air diffusing unit at least on an upstream side of the denitrification confirming unit, so that a desired proportion of the nitrate is denitrified at the halfway position, based on the denitrification state confirmed by the denitrification confirming unit.

Abstract: Provided is a water treatment system that prevents overlook and misdetection of abnormal flocculation. The water treatment system includes a mix tank, a flocculation tank, a plurality of floc-particle-diameter measurement devices, a fault detection device that detects abnormal flocculation, and a notification device that notifies occurrence of the abnormal flocculation. The fault detection device includes: a calculator that calculates at least one of a difference and a ratio between particle diameters of floc; a storage that stores therein a tolerable range of at least one of the difference and the ratio between the particle diameters of floc; a determiner that, when the calculated value is within the tolerable range, determines that it is normal, and when the calculated value is outside the tolerable range, determines that it is abnormal; and an outputter that transmits an abnormal flocculation detection signal to the notification device.

Abstract: A wastewater treatment apparatus includes an air diffusing unit, a denitrification confirming unit, a nitrification confirming unit, a gas supply-amount control unit. The air diffusing unit supplies gas to nitrogen-containing water. The denitrification confirming unit provided at a first predetermined position confirms a denitrification state whether a desired proportion of the nitrate has been denitrified. The nitrification confirming unit provided at a second predetermined position confirms a nitrification state whether a desired proportion of the ammonia has been nitrified. The gas supply-amount control unit controls a gas supply amount at least on an upstream side of the denitrification confirming unit, so that the desired proportion of the nitrate is denitrified at the first predetermined position, and controls the gas supply amount at least on an upstream side of the nitrification confirming unit, so that the desired proportion of the ammonia is nitrified at the second predetermined position.

Abstract: Disclosed herein is a method capable of economically treating water containing water-insoluble substance. The method for treating water containing water-insoluble substance, typified by produced water, using a porous material having functional groups on its surface and preferably made of an inorganic oxide includes: a first step of bringing an aqueous solution containing ions ion-exchangeable for the functional groups into contact with the surface to attach the ions to the surface; and a second step of allowing the water containing water-insoluble substance to pass through the porous material from the surface having the ions attached thereto to remove the water-insoluble substance from the water containing water-insoluble substance. The method may further include, after the first step but before the second step, the step of firing the porous material under a temperature condition of 300° C. to 500° C. for 1 to 5 hours.

Abstract: The process includes operation as follows: putting ozone generated by an ozone generator into raw water, in a normal mode, to subject the raw water to ozone treatment; injecting a flocculant into the raw water before or after the ozone treatment; filtering the raw water by a separation membrane after the ozone treatment and the injection of the flocculant; and intermittently setting cleaning mode to put a larger quantity of cleaning ozone than that in the normal mode into the raw water so as to intermittently increase the concentration of dissolved ozone, thereby cleaning the filtration membrane.

Abstract: A method for measuring bromate ions includes: an adding step of adding a fluorescent substance whose fluorescence intensity changes by the coexistence of bromate ions to sample water; a measuring step of measuring the fluorescence intensity of the fluorescent substance; a difference calculating step of calculating a difference between the fluorescence intensity measured and a reference fluorescence intensity of reference sample water that contains no bromate ion; and a concentration calculating step of calculating bromate ion concentration from the calculated fluorescence intensity difference. The measuring step includes a step of measuring the fluorescence intensity at any one of a case where an excitation wavelength is 264 nm and an emission wavelength is 400 nm, a case where the excitation wavelength is 264 nm and the emission wavelength is 480 nm, and a case where the excitation wavelength is 300 nm and the emission wavelength is 400 nm.

Abstract: A method of wastewater reutilization by which reusable water can be stably obtained from a wastewater. Ozone is added to a wastewater, such as water resulting from sewage treatment, in such a small amount as to result in a residual ozone concentration as measured before membrane filtration of 0.01-1.0 mg/L. Ozone is thus brought into contact with fine solids contained in the wastewater to alter the surface properties of the fine solids so that the solids are easily to coagulate. Thereafter, a coagulant, e.g., PACl, is added from a coagulant addition device (3). The fine solids are coagulated in a coagulation tank (5) or a line mixer and the resultant water is subjected to membrane filtration with an ozone-resistant separation membrane (6) such as ceramic membrane. Thus, reusable water is obtained which has a residual ozone concentration, as measured after filtration through the membrane, less than 0.5 mg/L.

Abstract: An inside of an incinerator body into which sludge is fed is divided into a lower portion, a portion above the lower portion, and a top portion in a height direction. The lower portion serves as a pyrolysis zone for supplying fluidizing air having an air ratio of 1.1 or less together with fuel to thermally decompose the sludge while fluidizing the sludge. The portion above the lower portion serves as an over bed combustion zone for supplying only combustion air having an air ratio of 0.1 to 0.3 to form a local high temperature place to decompose N2O. The top portion serves as a perfect combustion zone for perfectly combusting unburned contents. The quantity of N2O generated during sludge incineration can be drastically reduced while maintaining the use quantity of auxiliary fuel at the same level as that of a conventional incineration method.

Abstract: A method for measuring bromate ion includes: a first step of introducing a test water sample to an anion exchanger that selectively absorbs bromate ions; a second step of introducing, to the anion exchanger, a hydrochloric acid solution containing a fluorescent substance, a fluorescence intensity of which is changed by the coexistence of bromate ions; a third step of measuring the fluorescence intensity of the fluorescent substance contained in the hydrochloric acid solution discharged from the anion exchanger; and a fourth step of using a calibration curve, which shows a relationship between the fluorescence intensity of the fluorescent substance and the concentration of the bromate ions, to calculate the concentration of the bromate ions that corresponds to the measured fluorescence intensity.

Abstract: A method for measuring bromate ions includes: an adding step of adding a fluorescent substance whose fluorescence intensity changes by the coexistence of bromate ions to sample water; a measuring step of measuring the fluorescence intensity of the fluorescent substance; a difference calculating step of calculating a difference between the fluorescence intensity measured and a reference fluorescence intensity of reference sample water that contains no bromate ion; and a concentration calculating step of calculating bromate ion concentration from the calculated fluorescence intensity difference. The measuring step includes a step of measuring the fluorescence intensity at any one of a case where an excitation wavelength is 264 nm and an emission wavelength is 400 nm, a case where the excitation wavelength is 264 nm and the emission wavelength is 480 nm, and a case where the excitation wavelength is 300 nm and the emission wavelength is 400 nm.

Abstract: A sewage treatment system, includes a solid-liquid separating apparatus having a first filtering medium packed layer packed with a predetermined filtering medium, configured to separate sewage to be treated into solid components and filtered water by passing the sewage through the first filtering medium packed layer upward, and configured to reversely wash the first filtering medium packed layer by passing the filtered water through the first filtering medium packed layer downward at a predetermining timing; and a trickling filter installed on a latter stage of the solid-liquid separating apparatus, having a second filtering medium packed layer packed with a filtering medium attached with microorganisms, and configured to allow the filtered water to fall into the second filtering medium packed layer by trickling the filtered water onto an upper part of the second filtering medium packed layer to flow out treated water acquired by biotreating the filtered water by the microorganisms.

Abstract: A backwashing method incorporating a membrane filtration apparatus in which a ceramic filtration membrane including a substrate layer 11b having an extremely large number of filtration pores and a separating layer 11a having filtration pores smaller than those of the substrate layer is accommodated in a casing. Air controlled to a pressure p1 is supplied to the secondary side of the filtration membrane so as to drain the filtrated water in the membrane filtration apparatus gradually toward the primary side. After that, air pressure is increased to p3 so as to push the water in the filtration membrane toward the primary side together with the air, thereby peeling off any fouling substances. Unlike in conventional cases, a large amount of backwashing drain water is at no time drained at any one time, and thus, without reducing the effectiveness of backwashing, a backwashing drain pipe can be designed to have a small diameter.

Abstract: A filtering and condensing apparatus of a suction type includes: a sludge tank for containing sludge to be filtered and condensed; a plurality of filtering plates aligned with each other so as to be disposed to be adjacent to each other in the sludge tank; a means for constantly applying a tension force to each of the filtering plates, which means is disposed to be over a periphery of each filtering plate. A filtering cloth of each filtering plate is divided in the lateral direction by a plurality of vertically extending seams to form multiple divided zones, in each of which zone a filtering chamber is formed. A weight member is attached to a lower portion of each filtering plate using a U-shaped body.

Abstract: A method for measuring bromate ion includes: a first step of introducing a test water sample to an anion exchanger that selectively absorbs bromate ions; a second step of introducing, to the anion exchanger, a hydrochloric acid solution containing a fluorescent substance, a fluorescence intensity of which is changed by the coexistence of bromate ions; a third step of measuring the fluorescence intensity of the fluorescent substance contained in the hydrochloric acid solution discharged from the anion exchanger; and a fourth step of using a calibration curve, which shows a relationship between the fluorescence intensity of the fluorescent substance and the concentration of the bromate ions, to calculate the concentration of the bromate ions that corresponds to the measured fluorescence intensity.