CAUTION: Maintain significant figures through all calculations! A tracer study was conducted on a full-scale reactor that has a volume of 780,000 gallons by injecting a slug of chloride into the influent and then measuring the effluent concentration with time. 25 36 43 45 46 Time (minutes after dye was injected) 0.10 0.20 0.30 0.40 0.50 0.75 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Chloride Concentration (mg/L) 0.0 5.0 5.5 6.0 6.6 7.4 8.6 9.4 10 11 12 13 14 15 5.0 6.0 7.0 8.0 9.0 10 11 12 13 14 15 45 44 21 9.8 8.7 7.3 6.2 5.6 4.7 4.1 3.0 16 17 18 19 20 5. A sub-surface wetland treating runoff from a dairy farm is to be modeled as a first order plug flow reactor with a k' of 2.76/day. The storm water entering the wetland has a BODs of 225 mg/L and regulatory discharge limits of 10.0 mg/L of BODs. If the wetland has a surface area of 2.70 acres and an average depth of 6.00 inches, how much flow can be treated and what is the detention time of the water within the wetlands? 6. Discuss all assumptions associated with the calculations in question number 5