1933 (U.S. Patent Office) 5 Sept. 177/1 An anaerobic digester compartment beneath said clarifier compartment to receive the raw sludge therefrom.
2012 5 June 12/3 He has for the past four years made more than £1,000 a day feeding the local electricity grid via an anaerobic digester (AD) that provides power from cattle manure and other waste products.