Question

16-Ciy-A3 May 2017 Closed-Book Problem 1 Provide answers to the following questions as relate Elementary Environmental Engineering d to environmental engineering material balances, reaction kinetics and microbiology and (6) (i) Under ambient environmental conditions the rate of iron (Fe2) oxidato and precipitate out of solution is sccond order with the rate constant these conditions apply, what mean residence time (t in min) is lower the necessary in a completely stirred tank reactor (CSTR) at steady state to Fe2t concentration from 10 μΜ to 5μΜ? If the flow rate is 1 m3/s, what reactor size is required? Recall that: dC kd resulting in Co C C, (6) (ii) Consider the reaction of cumene hydroperoxide (CHP) to phenol and acctone: (CsHs)C(CH3)200H → (C6Hs)OH + (CH3)2CO CHPPhenol +Acetone Assuming that the reaction is pseudo-first order with rate constant r -k CCHP, lind the reactor volume (V in m3) to Assume that the flowrate into the reactor is Q 30 m3/hr and k- 4 hr- achieve a 90% conversion of CHP at steady state

Answer 1

Solutioh t= 20 Sec dc kt 2.302, t-o.sg劾. ~ V'= 3 xo.sg ם , 7.27m3