Passage I
Two artificial marshes were built to help reduce the amounts of iron and manganese in, and the acidity of, water seeping into a stream from a coal mine site (see Figure 1). Table 1 shows precipitation, in centimeters (cm); flow rate, in liters per minute (L/min); pH (acidity); and iron and manganese content, in milligrams per liter (mg/L), of inlet and outlet water over 5 days.
Water having a higher level of iron or manganese or a lower pH than the values given in Table 2 is said to be contaminated.
1. Which of the following figures best represents the iron concentrations at Outlet 2 for the 5-day period?
Your Answer is
Correct Answer is D
Explanation
Looking at table 1, the Iron concentration of Outlet 2 is the lowest on Day 2, which is 5.0 mg/L;
It is the highest on Day 3, which is 22.7 mg/L, so it should be option D