Abstract: A compound selected from the group consisting of 4-quinolone and derivatives thereof, homoserine lactone derivatives, and indole and derivatives thereof, and salts thereof have an action of a microbial activity improvement agent, and when it is used for a microbial activity improvement method and a biological waste treatment method, the compound or the salt thereof is useful to achieve the improvement in the treatment capacity that transcends the limit of improvement in the treatment capacity of conventional biological waste treatment facilities.

Abstract: The present invention provides a method for treating wastewater containing ammonia nitrogen, in which an entire nitrification reaction to convert ammonia nitrogen to nitrate nitrogen via nitrite nitrogen is promoted by allowing nitrifying bacteria to perform the nitrification reaction in the presence of an intermicrobial signaling molecule.

Abstract: A compound selected from the group consisting of 4-quinolone and derivatives thereof, homoserine lactone derivatives, and indole and derivatives thereof, and salts thereof have an action of a microbial activity improvement agent, and when it is used for a microbial activity improvement method and a biological waste treatment method, the compound or the salt thereof is useful to achieve the improvement in the treatment capacity that transcends the limit of improvement in the treatment capacity of conventional biological waste treatment facilities.

Abstract: The present invention provides a method for treating wastewater containing ammonia nitrogen, in which an entire nitrification reaction to convert ammonia nitrogen to nitrate nitrogen via nitrite nitrogen is promoted by allowing nitrifying bacteria to perform the nitrification reaction in the presence of an intermicrobial signaling molecule.

Abstract: 1. A coating composition to form a coating layer or film of a hydrophilic polyurethane resin having a moisture permeability and being substantially non-porous, which comprises, as an essential component, an isocyanate group-containing prepolymer obtainable by reacting diphenylmethane diisocyanate with the following polyoxyalkylene polyol: A polyoxyalkylene polyol which contains at least 60 wt % of a polyoxyethylene polyol having at least three hydroxyl groups and having an oxyethylene group-content of at least 10 wt %, satisfies 3.0<n<3.5, where n is the average number of hydroxyl groups, and has an average oxyethylene group-content of from 60 to 90 wt %.

Abstract: A coating composition to form a coating layer or film of a hydrophilic polyurethane resin having a moisture permeability and being substantially non-porous, which comprises, as an essential component, an isocyanate group-containing prepolymer obtainable by reacting diphenylmethane diisocyanate with the following polyoxyalkylene polyol: