Some O2 is present in water. The water will be considered as “polluted water” when concentration of O2 in it will be?
A. 4 – 8 ppm
B. Less than 4 ppm
C. Greater than 4 ppm
D. Greater than 8 ppm
Answer:B
Some O2 is present in water. The water will be considered as “polluted water” when concentration of O2 in it will be?
A. 4 – 8 ppm B. Less than 4 ppm C. Greater than 4 ppm D. Greater than 8 ppm