Dr. Eng. Christoph Julius PLATZER is a civil-sanitary engineer from the Technical University of Munich/Germany (1990), with a doctorate in sanitary engineering from the Technical University of Berlin/Germany (1997), specialist in effluent treatment. He works mainly with sewage treatment solutions, including activated sludge, its variations, sludge and effluent treatment wetlands, energy efficiency and biogas. He is an author of more than 70 publications, director at Rotária do Brasil – a company that implements turnkey solutions for STPs – and he is also an international consultant.