Dr. Domènec Jolis has more than thirty-five years of experience in wastewater treatment engineering, with special emphasis on biological treatment. He has led numerous research projects covering many unit processes including primary, secondary, and tertiary treatment as well as anaerobic digestion and solids handling and has published extensively on the results. While working at publicly owned treatment facilities on optimization, troubleshooting and upgrade of processes, Dr. Jolis enjoyed teaching the fundamentals of process engineering to engineers and operations and maintenance staff.