Water may be purified by passage through a filter of thickness 2 cm to 1 m composed from fibers obtained from a melt of composition about 80% diabase mineral and about 20% lime, at least 90% of the fibers having a diameter below 15 microns, the fiber solids content of the material being at most 20% of the volume at a flow rate above 10 meters per hour to remove suspended particles.

A process is described for purifying lactams, in particular the lactams obtained by cyclizing hydrolysis of an aminoalkylnitrile, and more particularly to the purification by crystallization of .epsilon.-caprolactam obtained by cyclizing hydrolysis of aminocapronitrile. This crystallization is carried out on the cyclization reaction medium after hydrogenation, removal of volatile compounds, and treatment with an ion-exchange resin.

Exhaust gas purifying catalyst characterized in that a carrier carries as the catalytic elements, a Pt-family element or elements containing over 50 weight % of Pt and an alkaline metal in proportions of 0.001.about.1 mole per 1 kg of catalyst; or the carrier carries Ce additionally.

An exhaust gas purifying catalyst includes a carrier and a catalyst layer provided on the carrier. The catalyst layer includes active Al.sub.2O.sub.3 on which a noble metal is carried, an oxygen storage agent on which Rh is carried, Al.sub.2O.sub.3 coated with ZrO.sub.2 on which Rh is carried, and a binder material.

A method for purifying yellow phosphorus is disclosed comprising contacting the molten phosphorus with a solid phosphorus acid containing catalyst comprising an oxygen acid of phosphorus carried on an inert absorbant support. The purified phosphorus is thereafter separated from the solid catalyst and preferably is separated therefrom by filtration through the catalyst layer.

The invention relates to a method and an installation for separating sulphur dioxide from exhaust gas, wherein sea water is added to the exhaust gas in an absorption column and the sea water charged with sulphur compounds is extracted from the liquid sump of the absorption column and fresh sea water is added thereto.In order to omit the very expensive and large secondary reaction basis according to the state of the art, it is proposed to extract the liquid, which contains the bisulphates, from t...

A process is provided for removing suspended solids from a waste water stream exiting from a wet rendering plant, a centrifugal rendering plant and/or a hide curing brine system before the stream enters a public sewer system. Such waste water typically has some oils, fats and/or protein particles in addition to easily settled solids previously removed therefrom. The waste water is delivered to a holding tank wherefrom the waste water is drawn and pH adjusted with sodium carbonate, sodium hydroxi...

There is disclosed an exhaust gas purifying filter of the present invention comprising a honeycomb structure formed of a porous ceramic material and including: a large number of through-holes 3; plugged portions 10 formed in one end portion of each of predetermined through-holes 3 and in the other end portion of each of remaining through-holes 3; and partition walls 2 partitioning the through-holes 3 and formed into filter layers, characterized in that a plugging length is non-uniform for each p...

Provided is a method of purifying a macrolide, especially tacrolimus, that includes loading macrolide onto a bed of sorption resin and elting with a suitable eluent such as a combination of water and tetrahydrofuran.

A process for purifying propylene oxide characterized by subjecting a liquid reaction mixture containing propylene oxide, and water, hydrocarbons and oxygen-containing organic compounds as impurities obtained by reacting cumene hydroperoxide with propylene to extractive distillation using an extractant of a hydrocarbon having 7 to 20 carbon atoms with an extractive distillation column, and controlling a concentration of propylene glycol in the extractant supplied to the extractive distillation c...