Abstract: An amidase or nitrilase is made by continuous culture under carbon limitation using a carbon source which includes, respectively, either (a) an amide or amide precursor or (b) a nitrile or nitrile precursor. Novel enzymes have particular stability. A novel microorganism is Rhodococcus rhodochrous NCIMB 40756 and is capable of producing a particularly stable amidase. The novel amidase, and the amidase made by the defined process, are effective for converting (meth)acrylamide to ammonium (meth)acrylate, for instance in or after the polymerisation of the acrylamide.

Abstract: A polymeric amphipathic stabilizer is formed of hydrophobic monomer units and hydrophilic monomer units which comprise carboxylic free acid or acid salt units and glycidyl or anhydride units. The glycidyl or anhydride units react onto reactive groups on polymer particles when dispersed in non-aqueous liquid and provide improved stability when the particles are subsequently dispersed in liquid electrolyte.

Abstract: A sludge, preferably derived at least in part from a paper mill, pulp mill or deinking plant, and which contains at least secondary sludge or primary sludge comprising deinking waste, recycled paper waste or mechanical pulping waste, is flocculated by being mixed with a phenolic material and a polyalkylene oxide and is then subjected to dewatering.

Abstract: The present invention relates to a method for ore pelletization including the step of adding binder polymer to particulate ore and moisture to form an intimate mixture. Green pellets are formed from the mixture and fired. A water soluble treatment polymer having a molecular weight of 1,000 to 20,000 is included in the intimate mixture in an amount of at least 0.001% by weight. The water soluble treatment polymer is formed by polymerization of water soluble ethylenically unsaturated monomer blend containing at least 50% by weight of anionic monomer.

Abstract: Flexographic or other printed paper is deinked by a process which comprises pulping in the presence of an emulsion of crosslinked, insoluble, ionisable and swellable polymer particles. The emulsion preferably provides a viscosity (at 3%) in the ionised state of below 50,000 cps (Brookfiled RVT) and is novel.

Abstract: The aqueous clay waste formed during a phosphate or other mineral recovery processes is flocculated in a well which is generally formed in a sedimentation lagoon, the supernatant is taken from the top of well and is recycled to the main flotation or other separation process (generally after running across sediment in the lagoon) and the thickened sediment which is formed in the well is pumped from the base of the well to one or more final lagoons where it is converted to a solid sediment by sedimentation and evaporation.

Abstract: Belt pressing or other pressure dewatering of a high solids mineral suspension is facilitated by flocculating the suspension by mixing into the suspension anionic flocculant having IV at least 5 dl/g and a minor amount of a cationic flocculant which generally has IV at least 4 dl/g. The flocculants are normally such that counterionic precipitation occurs.

Abstract: Primary polymer particles having a size at least 90% below 10 .mu.m and which contain water soluble and water insoluble polymer are made by reverse phase polymerisation of a water soluble ethylenically unsaturated monomer or monomer blend with cross linking agent, and the emulsion is then spray dried to form spray dried granules which disintegrate upon addition to water, thereby forming an aqueous composition of the insoluble particles having activity similar to the starting emulsion. This aqueous composition of insoluble particles is particularly useful for flocculation, for instance flocculation of sewage sludge followed by centrifugation or belt pressing, or for viscosification.

Abstract: An oil in water emulsion comprises a continuous aqueous phase and a discontinuous oil phase which is either a hydrophobic liquid which is immiscible with the aqueous phase or is a solid phase obtained by providing an emulsion in the aqueous phase of a solution of potentially solid material in the hydrophobic liquid and converting this solution to a solid phase, and the emulsion is stabilized by the inclusion of water-soluble stabilizing polymer in the aqueous phase and oil solubilizing stabilizing material, generally polymer, in the oil phase. The or each polymer is preferably a copolymer of hydrophilic and hydrophobic groups, preferably being formed by copolymerization of water-soluble monomer and oil-soluble monomer that provide the desired groups in the polymer without further reaction. Partially hydrolyzed polyvinyl alcohol can be used as the water-soluble polymer.

Abstract: Paper making processes, including microparticulate processes, which utilise bentonite are provided with bentonite in the form of a concentrate, or a dilute dispersion made by diluting the concentrate, wherein the concentrate is a dispersion of 15 to 40% by weight bentonite in water containing citrate and has a viscosity below 5000 cps and is a stable fluid. The concentrates are novel. They are preferably made by mixing alkaline earth bentonite with water and sodium citrate.

Abstract: Surface solids formation during sedimentation of a flocculated mineral suspension is minimised by flocculating the suspension with flocculating agent in the presence of surfactant, provided that the flocculating agent and surfactant are not counterionic.

Abstract: A stable, pourable, liquid composition contains 20 to 60% by weight of a blend of a water soluble high IV polymer and a water soluble low IV cationic coagulant polymer, is selected from polyamines, cationic dicyandiamide polymers and polymers of 70 to 100% ethylenically unsaturated cationic monomer with 0 to 30% by weight acrylamide, and contains 0.01 to 1 part by weight of a water soluble multi-hydroxy compound per part by weight of the coagulant polymer.

Abstract: Alkaline earth bentonite can be activated by the use of sodium citrate or other organic sequestering agent as activator. Dry blends of the activator and the bentonite can be provided.

Abstract: Aqueous drilling and reservoir fluids are provided comprising polymers with shale and clay inhibition characteristics. These polymers are dissolved in the fluid and are formed from 50 to 100 mo % monomers of formula (I), wherein R.sup.1 is selected from H and C.sub.1 to C.sub.4 alkyl groups; R.sup.2 is selected from C.sub.1 to C.sub.4 alkyl groups, --C(CH.sub.3).sub.2 CH.sub.2 COCH.sub.3, --CH.dbd.CH.sub.2 and --C(CH.sub.3).dbd.CH.sub.2. R.sup.3 is selected from H, C.sub.1 to C.sub.4 alkyl groups, CH.sub.2 .dbd.CH-- and CH.sub.2 .dbd.C(CH.sub.3)--; wherein when R.sup.3 is H or C.sub.1 to C.sub.4 alkyl then R.sup.1 is H and R.sup.2 is --CH.dbd.CH.sub.2 or --C(CH.sub.3).dbd.CH.sub.2 and when R.sup.2 is --C(CH.sub.3).sub.2 CH.sub.2 COCH.sub.3 then R.sup.1 is H; 0 to 50 mol % other ethylenically unsaturated non-ionic monomers and 0 to 20 mol % ionic ethylenically unsaturated monomers and the polymer has a molecular weight of below 1 million.

Abstract: Large crop areas are irrigated, for instance by pivot irrigation, by being sprayed with water into which a substantially stable dispersion in a liquid of water soluble polymer particles has been metered at a predetermined low rate.

Abstract: Nitrilase enzymes are provided which have Km at pH 7.0 for acrylonitrile of 500 .mu.M or below. The enzymes also have Ki at pH 7.0 for ammonium acrylate of at least 100 mM. In particular, the nitrilases have a value of the ratio of the said Ki to the said Km of at least 200. Particularly preferred nitrilases are obtainable from the microorganisms Rhodococcus rhodochrous NCIMB 40757 or NCIMB 40833. These nitrilases can be used in processes of converting acrylonitrile to ammonium acrylate in aqueous or vapor form and for detecting low levels of nitrile in aqueous or vapor form.

Abstract: Acrylamidase enzymes are provided which have acrylamidase activity at pH 4.0 which is at least 50% of their acrylamidase activity at pH 7.0. Such enzymes can be produced by the novel microorganisms Rhodococcus strains NCIMB 40889 and NCIMB 40755. Such enzymes and microorganisms can be used for reducing free acrylamide in polyacrylamides which are produced at low pH and in particular cationic and substantially non-ionic polyacrylamides.

Abstract: Paper is made by a dual soluble polymer process in which a cellulosic suspension which usually contains alum or cationic coagulant is first flocculated with a high intrinsic viscosity cationic synthetic polymer or cationic starch and, after shearing, the suspension is reflocculated by the addition of a branched anionic water soluble polymer having an intrinsic viscosity above 3 dl/g and tan delta at 0.005 Hz of at least 0.5. The process gives an improved combination of formation, retention and drainage.

Abstract: Substantially clear gelled compositions suitable for use in cosmetics or pharmaceutical compositions and containing cationic polymer are formed by solvating a reverse phase emulsion of water soluble or water swellable cationic polymer in a liquid hydrophobic ester of a polyol with a polyol mixture which contains propylene glycol and/or butylene glycol together with glycerine in proportions which result in a composition having a clarity of below 30 NTU.