Streptomycin is used as an antibiotic to fight bacterial diseases in humans as well as to control bacteria, fungi, and algae in crops. First an inoculate is prepared by placing spores of strains of Streptomyces griseus in a medium to establish a culture with a high biomass. The culture is then introduced into a fermentation tank which operates at 28C and a pH of about 7.8 with the nutrients of glucose (the carbon source) and soybean meal (the nitrogen source). High agitation and aeration are needed. After fermentation, the biomass is separated from the liquid, and Streptomycin is recovered by adsorption on activated charcoal followed by extraction with an organic solvent in a continuous extraction process. If we ignore the details of the process and just consider the overall extraction process, Figure 1 shows the net result.

Determine the mass fraction of Streptomycin in the exit organic solvent based on the data in Figure 1, assuming that:

(1) no water exits with the solvent and no solvent exits with the aqueous solution, and

(2) the density of the aqueous solution is 1 g/cm³ and the density of the organic solvent is 0.6 g/cm³

Organic solvent S 10 L/hr p = 0.6 g/cm3 No Strep Aqueous solution A 200 L/hr 10 g Strep /L p = 1 g/cm3 Extraction Process Aqueous solution B 0.2 g Strep/L Organic solvent Extracted Strep