Design a CSTR to provide pretreatment for an industrial wastewater that flows at a rate of 1,000 fpm with a phenol concentration of 200 mg/L. Phenol undergoes a first-order decay reaction in the CSTR with a rate constant, k=0.50 hr^(-1). The current industrial pretreatment permit limitation for phenol is 20 mg/L. The permit limitation may be changed, either higher or lower, in the future. 1. Determine the required CSTR volume, V (in gallons), and hydraulic residence time, in V/Q (hours), to comply with the current industrial pretreatment permit limitation for phenol. 2. Plot a graph with CSTR effluent phenol concentration in mg/L along the vertical axis as a function of CSTR hydraulic residence time in hours, on the horizontal axis for assessing the impact of changes in the permit limitation. Use a spreadsheet to perform the repetitive calculations and then use the spreadsheet's graphing tools to plot the graph. Comment on a type of "Law of Diminishing Returns" on effluent phenol concentration versus the V/Q that applies to CSTR design for first-order decay reactions.