A sewage lagoon that has a surface area of 10 ha and a depth of 1 m recieving 8640m3*d-1 of sewage containing 100 mg*L-1 of biodegradable contaminant. At a steady state, the effluent from the lagoon must not exceed 20mg*L-1 of biodegradable contaminant. Assuming the lagoon is well mixed and that there are no losses or gains of waterin the lagoon other than the sewage input, what biodegradation reaction rate coefficient (d-1) must be achieved fo a first-order reaction?