Biography

Gerrit v R. Marais

Distinguished Departed Pioneer

Professional background

Gerrit van Rooyen Marais (1927-2005) was professor at the University of Cape Town, South Africa.  

Early in his career he made significant contributions to low-cost water supply and sanitation, for example in Zambia. In the 1960s he developed a novel instrument for measuring dissolved oxygen in oxidation ponds and was awarded a prize in 1967 by the South African Institute for Civil Engineers for the most innovative paper. He was member of the Expert Committee on Environmental Sanitation of the World Health Organization and was invited as a Distinguished Foreign Professor by the American Society of Sanitary Engineering. In 1989 he was elected Fellow of the Royal Society of South Africa. 

Major Contributions to IWA

Marais’ research at the University of Cape Town has had a major influence within IWA on biological nutrient removal, filamentous bulking, and anaerobic digestion. In 1983 Gerrit was appointed by IAWPRC (the predecessor of IWA), together with four other researchers (Willi Gujer, ETH, Switzerland; Les Grady, Clemson University, USA; Tom Matsuo, University of Tokyo, Japan; Mogens Henze, DTH, Denmark) to serve as an International Task Group for modelling biological wastewater treatment systems. The group created the Activated Sludge Model in various versions (ASM1, ASM2 etc.). The models have been the cores for development of numerous biological wastewater treatment models since 1986. The stepwise ASM development was built on the original approach in 1976 by Marais and his colleague George Ekama.  

Author:  Gustaf Olsson, Sweden