Abstract: An improved method and apparatus for regeneration and reuse of He--N.sub.2 --CO.sub.2 mixed gas for carbon dioxide gas laser. The laser gas after use is contacted with a noble metal catalyst (for example, Pt--Al.sub.2 O.sub.3) at a temperature of 200.degree.-300.degree. C. to react CO and O.sub.2 formed by laser discharge so as to form CO.sub.2. A suitable quantity of moisture in the contained laser gas causes steam-reforming reaction of H.sub.2 O and CO, and reaction of H.sub.2 and O.sub.2 following thereto, and continuous operation over a long period is thus possible. Poisoning of the catalyst by NO.sub.x is suppressed at this relatively high temperature of reaction. Activity of the catalyst, when decreased, may be recovered by reactivation by passing a reactivating gas consisting of carbon monoxide, oxygen and helium through the catalyst bed at a temperature of 400.degree. to 500.degree. C.

Abstract: A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed.After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement.The concentrated liquid may also be dried into a powder using a thin film evaporator.

Abstract: An apparatus for compacting a solid waste material includes a hollow cylindrical body having a charging inlet for charging the solid waste material therethrough into the hollow cylindrical body, a heating portion for heating the solid waste material in the hollow cylindrical body, and a discharging outlet for discharging the solid waste material from the hollow cylindrical body; a rotatable shaft disposed in the hollow cylindrical body and having a helical screw blade thereon, the screw blade and an inner wall surface of the hollow cylindrical body being spaced from each other with a clearance provided therebetween for allowing the solid waste material in the hollow cylindrical body to form a bridge therein; a support for radially movably supporting an end of the rotatable shaft; a prime mover coupled to the end of the rotatable shaft through the support; and an outlet nozzle coupled to the discharging outlet for compressing the solid waste material discharged from the discharging outlet.

Abstract: An apparatus for filtering a suspension by at least one aggregate of membranes made of a high molecular weight compound porous hollow fibers to separate a filtrate from the suspended matter contained in the suspension, backwashing the aggregate of membranes with a backwashing gas to clean it and minimizing the amount of suspended matter entrained by the backwashing gas, and repeating the filtration and backwashing alternately, comprises a filtering vessel divided into a feed region and a filtrate region, the filtrate region being above the feed region, an inlet for the suspension at the feed region, an outlet for the filtrate at the filtrate region, an inlet for a backwashing gas in the filtrate region, an outlet for the backwashing gas in the feed region, a partition plate in the filtering vessel to support the aggregate of membrane filters and to divide the inteior of the filtering vessel into the filtrate region and the feed region, an outlet for a portion of the suspension in the feed region at a position

Abstract: A liquid-gas contactor which comprises a first liquid-gas contacting region of which the lower part is provided with a gas inlet and the upper part is provided with a liquid feed inlet and a second region through which flows a gaseous fluid comprised of particles of at least a portion of the liquid fed into said first contacting region suspended in the greater part of the gas supplied through the gas inlet. The first and second regions are interconnected in the form of an inverted U-shape, the bottom ends of both regions opening into a liquid tank and at least the bottom end of the first liquid-gas contacting region being submerged in the liquid in the tank. A liquid-gas contact process employs this contactor.