Patents are a rich and important source of scientific and technical information, much of which is not published elsewhere. The patent literature is interdisciplinary and international, encompassing innovations in every field of technology during the last two hundred years. Patents contain solutions to technical problems and engineering challenges. Patents reveal the current state-of-the-art and provide vital information for making informed decisions about new research projects and business opportunities.
The following selected CPC codes can be used to retrieve patents related to water, waste water, sewage, or sludge. Please note that these codes are starting points. Each may contain many subcodes related to specific designs, elements, methods, and applications. Also note that the list is not exhaustive.