Penicillin is recovered from an aqueous stream (H2O = 1000kg/m3 ) in a solvent extractor mixer-settler unit

Penicillin is recovered from an aqueous stream (ρH2O = 1000kg/m3 ) in a solvent extractor mixer-settler unit using MIBK (ρMIBK = 797.8 kg/m3 ) as a solvent. For a feed of 25 m³/h containing 10 kg/m³ of penicillin, 

(a) Determine the volumetric flow rate of solvent required if the final penicillin concentration in the aqueous stream is to be reduced by 90%. 

(b) If a second mixer settler is available determine the fresh solvent feed needed to reduce the aqueous penicillin stream from the first unit by a further 90%. 

Note: the equilibrium relationship between the penicillin concentration in the organic (kg/m3 ) and aqueous (kg/m³) phases is K=  C_org / C_aq  = 20