Raw sewage may be presently treated by mixing screened raw sewage with activated carbon. The mixture is then allowed to stand in a first tank for a period required to settle the suspended matter to the bottom of the tank as a sludge. Thereafter, the remaining liquid is again mixed with activated carbon and the mixture is transferred to a secondary settling tank, where it is permitted to stand for a period required for the remaining floating material to settle as sludge and for adsorption of sewa...

A system for filtering hydraulic fluid wherein a high flow rate of uncontaminated fluid is required. A housing having a paper filter element disposed therein is placed in a main oil flow line. The housing has a removable cover to which is fixed a rigid cylindrical baffle means which immediately confronts oil entering the inlet to the housing. With this arrangement cold, viscous oil entering the housing through the inlet thereof, which would normally tend to crush the paper filter element, imping...

The waste water of a sulfite pulp mill containing lignin and lignin derivves which are not bio-degradable is purified by contact with a fixed bed of granular, porous .gamma.-alumina having a particle size of 0.5-10 mm and a specific surface area of at least 140 m.sup.2 /g.

A semi-permeable membrane containing a catalyst for conversion of hydrogen peroxide introduced from one side of the semi-permeable membrane to molecular oxygen which is released from the opposite side of the semi-permeable membrane. The catalyst is preferably in the form of a ruthenium oxide or sulfide and preferably in assymetrical distribution in the membrane.

A flexible semi-permeable tubular assembly is provided which consists essentially of a cord comprising a textile sheath which carries a semi-permeable membrane, said sheath being composed of yarns, the external surface of the sheath being compressed and flattened, the internal surface of the sheath defining an axial channel which communicates with the exterior. This assembly is particularly suitable for the concentration, separation and purification of fluids by reverse osmosis, ultra-filtration...

An oil filter having a Belleville spring bypass valve mounted together with a rubber anti-drainback valve on a two-piece sheet metal filter cartridge support to form a subassembly which can readily be assembled in the oil filter canister and wherein the support member in addition to supporting a filter cartridge in the canister also provides a bypass passageway and valve seat for the bypass valve.

Liquid treating apparatus, for instance, a degasser for contaminated drilling mud returned from a well, comprising a treating chamber in which liquid to be treated is subjected to a suction source. A centrifugal impeller is rotatably mounted immediately adjacent the suction source communication with the chamber for repelling liquid droplets tending to enter the suction source, while admitting gaseous matter into the suction source.

Supply of zinc and nitrogen plant nutrients to plants growing in soil is effected by applying to the soil substantially anhydrous liquid ammonia containing an ionic solution of a zinc carboxylate.

A fertilizer from which potassium is released slowly comprises a frit produced from a potassium/silicon composition in the range K.sub.2 O.2SiO.sub.2 to K.sub.2 O.4SiO.sub.2 and containing from 5.5% to less than 10% by weight of calcium oxide.

Apparatus is disclosed for treating textile desizing effluent so as to provide effective pollution abatement, and to render feasible the recovery of sizing material from the effluent for reuse as well as the conditioning of the effluent so that it may be recycled for desizing purposes.