Water Treatment Operator-in-Training (OIT) Practice Test

To determine the rate of the chemical feeder in kg/min from its maximum rate of 900 kg per day, it's important to understand the conversion from days to minutes.

There are 24 hours in a day, and each hour has 60 minutes. Therefore, the total number of minutes in a day can be calculated as follows:

24 hours/day × 60 minutes/hour = 1440 minutes/day.

Now, to find the rate in kg per minute, you can divide the total daily rate by the total minutes in a day:

900 kg/day ÷ 1440 minutes/day = 0.625 kg/min.

This value can also be represented as a fraction, which is approximately 0.63 kg/min when rounded to two decimal places. This calculation highlights that the chemical feeder can provide a continuous and specific feed rate, maintaining consistency in the treatment process.

The value of 0.63 kg/min is thus the correct answer, as it accurately reflects the conversion of the daily maximum feed rate into a per-minute feed rate.