Question

A test bottle (Blank) containing just seeded dilution water has its DO level drop by 1.2 mg/L in a five-day test. A 300-mL BOD bottle filled with 30 mL of

wastewater and the rest seeded dilution water (this is a ratio of 30:300 or 1:10) experiences a drop of 6.8 mg/L in a five-day test. What is the BOD5 of the original wastewater (in mg/L)?

Fig: 1