The maximum temperature at which thermophilic microorganisms remain active in sludge digester is ___________
(a) 60^oC
(b) 40^oC
(c) 30^oC
(d) 20^oC
This question was addressed to me in unit test.
Asked question is from Digestion of Sludge, Sludge Digestion Tank in section Sewage Filtration and Activated Sludge Process of Environmental Engineering