Abstract: A method for reducing the level of hydrogen sulfide in water containing sulfur-reducing bacteria and hydrogen sulfide-metabolizing bacteria by addition of an aqueous solution of metallic nitrogen oxides and small particles of water-insoluble polycyclic quinones.

Abstract: A biodegradable composition suitable for the manufacture of low density loose-fill packing by extrusion, which is an aqueous dispersion comprising (1) finely divided particles of a gelatinizable starch product and (2) a water-soluble polymer dispersed in (3) water having dissolved therein (4) a copolymer of vinyl, methyl, ether and maleic anhydride.

Abstract: An improved process for the recovery of lactide or other dimeric cyclic ester from a gas stream containing the cyclic ester and such hydroxylic impurities as water and open-chain hydroxycarboxylic acids, by scrubbing the gas stream with a water immiscible solvent, such as, a non-polar hydrocarbon, a cycloaliphatic hydrocarbon or a halogenated hydrocarbon solvent, at a temperature at which the cyclic ester and the open-chain hydroxycarboxylic acids are scrubbed from the gas stream and any water present in the gas stream is carried away. The crude cyclic ester-acid composition is separated from the solvent and purified by extracting the acid impurities therefrom. The acid impurities are recovered and recycled.

Abstract: A dimeric cyclic ester of an alpha-hydroxycarboxylic acid (lactide) is separated and recovered from a vapor product stream containing the cyclic ester, the corresponding lower-boiling hydroxycarboxylic acid (lactic), higher-boiling oligomeric hydroxycarboxylic acid and water without the use of solvents. More specifically, the vapor stream is condensed to obtain a condensate containing substantially all the cyclic ester, and the condensate is refined by distillation means alone to recover the cyclic ester substantially free of water, the alpha-hydroxycarboxylic acid and the higher-boiling oligomers.

Abstract: Non-halogenated aqueous degreasing compositions-useful for removing inks and cleaning printed circuit boards comprising a three-component mixture of (1) an organic acid consisting essentially of an alkanoic acid, preferably a hydroxy-substituted alkanoic acid, (2) a straight chain alkanol having at least four carbon atoms or an alkyl ester derived from an unsubstituted or substituted alkanoic acid and a straight chain alkanol having at least four carbon atoms and (3) water.

Abstract: An optical recording element comprising a light-absorptive layer supported by a dimensionally stable substrate in which the light-absorptive material is a uniformly smooth, thin, homogeneous layer of film-forming polymeric dye having a light absorptivity of at least about 0.046 in the visible and/or infrared spectral regions.