A toxic substance was inadvertently added to the lagoon in the previous problem. If the toxic substance killed all of the microbes in the lagoon that were responsible for the degradation of the watse,what would the waste concentration be in the lagoon a week after the kill?Assume that prior to the kill,the concentration of waste leaving the lagoo was 3mg/l. The incoming waste concentration remains at 7 mg/l,and the flow through the lagoon remains at 1.2 million gallons pe day.