Professor Rittmann is a pioneer in using pre-genomic, genomic and post-genomic tools for studying the microbial ecology of engineered biological treatment processes. He is also an eminent international leader in the field of environmental biotechnology using microbial communities to provide services to society, with focus on biological wastewater treatment, microbial electrochemical technology, water recycling and resource (nutrients, energy) recovery.  He has published 520 manuscripts with over 17,611 citations (h index = 66 based on Scopus). His work is leading to new ways to clean up pollution, treat water and wastewater, capture renewable energy, and improve human health. He was elected to the National Academy of Engineering in 2004. He was named the Association of Environmental Engineering and Science Professors (AEESP) Distinguished Lecturer for 2004. The Distinguished Lecturer is selected by the Lecturers Committee of AEESP, in recognition of his or her excellence as both a researcher and educator and ability to give engaging oral presentations to members of the environmental engineering community and the general public. He is a Fellow of the American Association for the Advancement of Science, a recipient of the Clarke Prize for Outstanding Achievement in Water Science and Technology, a Distinguished Member of the American Society of Civil Engineers, and one of the world's most highly cited researchers in our field (Environmental Biotechnology), according to ISI. He was a recipient of the 2016 Perry L. McCarty/AEESP Founders' Award. This award is given annually to recognize the significant contributions of Professor McCarty to environmental engineering education, research, and practice and will be given to an environmental engineering or science professor who has record of excellence in these areas.