Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: A method and an apparatus for treating organic wastewater and sludge which remarkably reduce the generated amount of sludge at a much lower running cost, and which reduce the size and the capacity of the solubilization tank. The method and apparatus for treating sludge employs a biological treatment system, wherein a biological treatment of wastewater is carried out, and a solid-liquid separation unit for separating a solid from a liquid in the wastewater after the biological treatment, to obtain a treated wastewater and a sludge. The apparatus has a means for obtaining a withdrawn sludge from a part of the sludge and an alkali-treatment tank, wherein an alkali-treatment of the withdrawn sludge is carried out. The apparatus also has a biological solubilization tank which solubilizes the sludge after the alkali-treatment under an anaerobic, anoxic or microaerophilic condition, and a means for recycling the solubilized sludge to the biological treatment system.

Abstract: Provided are a method and an apparatus for treating organic wastewater and sludge, which remarkably reduce the generated amount of sludge at much lower running cost, and which get the size smaller the capacity of the solubilization tank. The method and apparatus for treating sludge has: an biological treatment system, which applies biological treatment to wastewater, a solid-liquid separation unit for separating a solid from a liquid in the wastewater after treating the biologically, to obtain a treated wastewater and a returned sludge. And the apparatus has means for obtaining a withdrawn sludge from a part of the returned sludge, an alkali-treatment tank, which applies alkali-treatment to the withdrawn sludge. The apparatus, also, has a biological solubilization tank, which solubilizes the sludge after treating the alkali-treatment under an anaerobic, anoxic, or microaerophilic condition, and a means for returning sludge to recycle the solubilized sludge to the biological treatment system.

Abstract: Phosphorus in wastewater is removed by using an apparatus including a settling tank, an anaerobic tank, an aerobic tank, and a final settling tank. Nitrogen in wastewater is removed by using an apparatus including a settling tank, an anaerobic tank, a nitrification tank, and a final settling tank.

Abstract: Phosphorus in wastewater is removed by using an apparatus including a settling tank, an anaerobic tank, an aerobic tank, and a final settling tank. Nitrogen in wastewater is removed by using an apparatus including a settling tank, an anaerobic tank, a nitrification tank, and a final settling tank.

Abstract: A composite member is made by fitting a functional member constituted by an aluminum composite material capable of providing a desired target function to a recess of a base material constituted by an aluminum alloy and provided with the recess on the surface required to exhibit the desired target function. The entire peripheral section exposed at the outer surface among the joining sections of the base material with the functional member is beam-welded in a non-oxidizing atmosphere. The beam-welded base material and the functional member are then subjected to diffusion bonding by pressing them at least in the fitting direction and heating them.

Abstract: A method for manufacturing an apex seal for rotary piston engines, comprising steps of providing a substrate made of an iron based material and having a portion wherein a sliding surface is provided, spraying the portion of the substrate with a molten-state Co-Mo-Si type intermetallic compound to form a coating of the compound, heating the coating of the compound by applying electron beams or laser beams to thereby make the intermetal compound dispersed in the substrate, heating the substrate to 580.degree. to 780.degree. C. to anneal it and machining the substrate into a configuration of the apex seal. The apex seal made in accordance with this method is also disclosed.

Abstract: A sliding member having a number of oil retaining pores is manufactured by forming a hard plating layer on a metal base, forming a masking resist film on the hard plating layer by exposure to light and development, forming a number of pores in the hard plating layer by effecting electrolytic etching at a current density of 50 to 600 A/dm.sup.2, dissolving said masking resist film and removing the same, and forming a hard ceramic film on the hard plating layer by vapor phase plating.

Abstract: An apex seal for rotary piston engines comprising a material containing in weight 2.5 to 4.0% of C, 1.5 to 3.0% of Si, less than 1.0% of Mn, 0.25 to 2.0% of Ni, 0.25 to 2.0% of Mo, 0.25 to 2.0% of Cu, 0.05 to 0.3% of B, 0.2 to 1.5% of Cr, 0.05 to 1.0% of V and balance substantially of Fe. The sliding surface portion of the seal is of a chilled structure containing in area ratio more than 55% of carbides and the body portion is essentially of bainite structure containing in area ratio less than 15% of carbides.