Abstract: A multiplicity of electrode plates, anodic and cathodic, are alternately arranged in an electrolytic tank side by side at short intervals in a row. A circulating current of the sludge being treated is caused to be produced within said electrolytic tank. Said circulating current including an upward current flowing upward between individual electrode plates and a surface current flowing above the row of the electrode plates and near the surface level of the sludge in a specified direction. Gas bubbles produced between the individual electrode plates and flocs present between the electrode plates are carried to the surface of the tank by said upward current. The surfaced bubbles and flocs being then carried by said surface current to a location which is generally outside the surface area above the elecrode plates. Air bubbles thus collected at one side of the electrolitic tank are beaten out by a shower of sludge falling thereon.

Abstract: The invention relates to an apparatus for cake removal in a filter press, and comprises a filter-cloth jolting mechanism as the cake removing means, with individual filter plates interconnected by loose connecting means for separating the filter plates one from another in equally spaced-apart relation. A jolting device for swinging the filter plates as carried by guide rails is connected to the filter plates, so that if the filter plates are caused to swing when they are in spaced-apart condition, lower end portions of adjacent filter plates are caused to strike against each other, such that a jolting effect is thereby given to associated filter cloths so that cakes are removed therefrom.

Abstract: A filter press of the type having a multiplicity of filter plates adapted to be sequentially separated from one another, one or more at a time, to allow removal of cakes from filter cloths between each two adjacent plates. A pair of filter cloths covering the opposed surfaces of each two adjacent plates are supported by support means adapted to allow up and down movement of the cloths between the two plates when separated from each other. Drive means for moving the cloths upwardly comprise a filter-cloth suspension-bar driving mechanism adapted for ready engagement with and disengagement from a filter-cloth suspension bar to which are secured the upper ends of the cloths.

Abstract: This invention relates to a filter press in which between a pair of heads a plurality of filter plates are connected to one another by loose connecting means. In the improved apparatus, the heads are both movable so that the filter plates may be moved in sequence, simultaneously from both end sides, toward the center to close the intervals therebetween or away from the center to provide intervals therebetween, whereby the time required in assembling and separating the filter plates can be considerably reduced. When the filter plates in assembled state, if one of the heads is pressed, while the other head is placed under action of stoppers, the filter plates are vigorously tightened by a cylinder having a shorter stroke than that in the prior-art apparatus.

Abstract: An arrangement for treating wastewater containing soluble organic matter through the proliferation of aerobic microorgnisms to purify the wastewater. In an apparatus having a wastewater tank, a water pervious drum rotatably mounted in the tank and partially submerged in wastewater therein, and a multiplicity of biological contactors packed in the drum, the improvement comprising the biological contactors being of hollow structure, each having at least two small openings, a subsidiary biological contactor being provided in the interior of each biological contactor where required, the contactors being compactly packed in the drum so as to be prevented from movement therein.

Abstract: A filter apparatus wherein the filter tank is separated by a water-penetrable partition wall into an upper section forming a filtrate reservoir and a lower section forming a filter chamber. Floating filter medium is placed in the filter chamber. Water to be filtered is fed into the filter chamber at the bottom thereof and caused to flow upward, passing through the floating filter medium. The filtrate is removed from reservoir.

Abstract: Sludge like sewage sludge is fed at the beginning of a path of travel of two endless belts of filter material. The sludge, carried between the two endless belts, is compressed and dehydrated between a drum which is supported in bearings with its periphery in contact with one of the endless belts and pressure belts which are trained around a plurality of rolls and brought into contact with the other of the endless belts. The pressure belts are composed of a multiplicity of narrow belts. Pressing by individual pressure belts is applied to the endless filter material belts at a suitable number of stages into which the path of the filter material belts is divided. Preferably, pressure is exerted on the sludge by a smaller number of pressure belts at early pressing stage and by a larger number of pressure belts at later pressing stages.

Abstract: A process for treating waste water such as sewage wherein waste water to be purified is brought successively into contact with a number of net units which are arranged in a treating tank with certain intervals therebetween. Organic substances in the waste water are removed due to decomposition caused by microorganisms which adhere to the net units. In the net units, water being in contact with the individual net units is always replaced, a disturbance is given to the water resulting in easy approach of the organic substances to the microorganisms, contact area between the organic substances and the microorganisms is large, and various kinds of microorganisms propagate. Thus, removal of the organic substances proceeds effectively and promptly. An apparatus which is suitable for carrying out the process is also proposed.

Abstract: An apparatus for treating waste water such as sewage in which at least one bundle of a number of straight tubes is submerged in waste water to be treated, said bundle being particularly provided with a plurality of crossing passages extending across the bundle which passages are arranged intermittently along the bundle with certain intervals therebetween so that no Poiseuille flow is substantially formed in each of the tubes. The waste water is flowed through the bundle of straight tubes in a direction along the bundle. In the bundle of straight tubes, organic substances in the waste water are removed due to decomposition caused by microorganisms which adhere to the inner surface of each tube. Owing to the presence of the crossing passages, removal of the organic substances proceeds effectively and promptly due to uniform flow distribution across the bundle, a disturbance of flow given to the water, propagation of various kinds of microorganisms and the like.

Abstract: In the filter press of the type in which a plurality of movable frame members are arranged between a pair of heads with at least one filter cloth supported therebetween, one of the heads of the press is movably supported so that the movable head may be advanced and retracted by a hydraulic cylinder for tightening the frame members, being carried out under a condition that the heads are closest to each other so that the frame members are tightened and the cakes-discharging operation being carried out by travelling the filter cloth under another condition that the heads are remotest from each other so that the frame members are separated and the other head of the press, which is fixed in conventional filter presses, is also supported movably so that it may be advanced and retracted.