A soft-drink bottling plant discharges a wastewater with a dissolved solids concentration of 10,000 mg/l NaCl at a rate of 100 gal/min to a stream. The stream above the discharge has a volumetric flow rate of 1.0 MGD and a dis- solved solids concentration of 25 mg/l. Below the discharge point is a prime fishing spot, and the fish are intolerant of salt concentrations above 200 ppm.
- Write the general equation for a mass balance.
- What is the combined flow in MGD of the stream and wastewater down-stream of the discharge?
- What is the concentration of dissolved solids (as NaCl) in the combined stream downstream of the discharge?