The present invention comprises a method for controlling (e.g. inhibiting) or killing microorganisms in an aqueous environment. The method includes the addition of an effective amount of monochlorourea or modifled monochlorourea to an aqueous solution. This aqueous solution may be a cooling water system, a recreational water system, a water treatment facility, or any circulating water system (i.e. a papermaking facility). A method of producing monochlorourea or modified monochlorourea is also disclosed.本發明包括控制(例如抑制)或殺滅水性環境中之微生物之方法。該方法包含向水溶液中添加有效量之單氯脲或經修飾單氯脲。此水溶液可為冷卻水系統、娛樂性水系統、水處理設施、或任一循環水系統(亦即造紙設施)。亦揭示製備單氯脲或經修飾單氯脲之方法。
