4. Which one of the following statements is correct with respect to Biochemical Oxygen Demand (BOD)? A. Secondary treatment of effluent decreases the BOD B. Secondary treatment of effluent increases the BOD C. Secondary treatment of effluent does not change the BOD D. Secondary treatment of effluent first increases and then decreases the BOD

4. Which one of the following statements is correct with respect to Bi

1.	4. Which one of the following statements is correct with respect to Biochemical Oxygen Demand (BOD)? A. Secondary treatment of effluent decreases the BOD B. Secondary treatment of effluent increases the BOD C. Secondary treatment of effluent does not change the BOD D. Secondary treatment of effluent first increases and then decreases the BOD
Answer» 4. Which one of the following statements is correct with respect to Biochemical Oxygen Demand (BOD)? A. Secondary treatment of effluent decreases the BOD B. Secondary treatment of effluent increases the BOD C. Secondary treatment of effluent does not change the BOD D. Secondary treatment of effluent first increases and then decreases the BOD