The European objectives in terms of quality of water bodies are increasingly strict and in addition to macropollutants, attention is also focused on micropollutants. The chemical sector is itself a producer of patents for their inventions for products used in water treatment. This Technology Watch of the essenscia Patent Cell includes a general study of the patents selected for their relevance in wastewater treatment in the chemical and pharmaceutical sector over the period 2005 to 2022, in which both the technology and substance axis were analysed.