A lagoon with a volume of 1200 m3 and a surface area of 400 m2 has been receiving a steady flow of a contaminant at a rate of 100 m3 /d for a long enough time that steady-state conditions apply. The contaminant entering the lagoon has a concentration of 10 mg/L. The chemical is subject to volatilization with a rate of 0.050 m/d and decay with a first-order rate constant of 0.95 /d. Assuming completely mixed and steady-state conditions, determine the concentration of pollutant in the effluent of the lagoon (in units of mg/L). b) If the input concentration of contaminant suddenly increased from 10 mg/L to 100 mg/L, what would the concentration be in the lake (in units of mg/L) after 1 day of receiving this new input?