A manufacturing process uses 100 kg/month of Solvent S to clean machine parts. Solvent S is volatile and 15% of it is lost to the atmosphere. 40% is recovered for recycling each month. The remainder leaves the plant in wastewater. What is the average concentration in mg/L of the solvent in the wastewater discharge if the average flow of the wastewater is 10 m3/d? a) 0.15 mg/L
b) 1,500 mg/L
c) 150 mg/L
d) None of the above