30)3. A treatment lagoon with volume 1000m3 has been receiving a steady flow of a waste at a rate of 30m3/ day for a long enough time to assume that steady-state conditions apply. The waste entering the lagoon has a concentration of 50mg/L and a first-order decay rate of 0.02/d. Assuming completely mixed conditions, (a) What would be the concentration of pollutant in the effluent leaving the lagoon? (b) If the input waste concentration suddenly increased to 100mg/L, what would be the steady-state concentration under the increased waste input? And what would be the concentration in the effluent 10 days after such increase? (c) If the lagoon has been operated for a long time under the conditions specified in (b), what would be the steady-state concentration after the input waste concentration is suddenly decreased to 25mg/L ? And what would be the concentration of pollutant in the effluent 30 days after this change of the waste input concentration