g wastewater is to be treated with aerated lagoons. You are considering two different design options: A) A single lagoon with a surface area of 180 m2 B) Two lagoons in series with surface areas of 90 m2 each. All ponds have a depth of 2 m. The flow rate of wastewater is 5000 L/day. The waste contains 600 mg/L of organic material that is readily biodegradable with a first-order rate constant of 0.35 day-1. What final effluent concentration of organic material would you expect for each design