Assertion: A mere 0.1 per cent impurities make domestic sewage unfit for human use.
Reason: Domestic sewage primarily contains biodegradable organic matter.

Fill in the blanks ____ % impurities make domestic sewage unfit for human use.

Read the following statements carefully and find the incorrect statements: A. More than 1 percent impurities make domestic sewage unfit for human use. B. Less BOD causes mortality of fish and other aquatic creatures. C. Presence of large amounts of nutrients in water also causes excessive growth of planktonic algae, called an algal bloom. D. Algai bloom causes deterioration of the water quality an decreases fish mortality. E. Some bloom-forming algae are extremely toxic to human beings and animals. F. Eichhornia crassipies is the world's most problematic aquatic weed.

Read the following statements carefully and find the incorrect statements: A. More than 1 percent impurities make domestic sewage unfit for human use. B. Less BOD causes mortality of fish and other aquatic creatures. C. Presence of large amounts of nutrients in water also causes excessive growth of planktonic algae, called an algal bloom. D. Algai bloom causes deterioration of the water quality an decreases fish mortality. E. Some bloom-forming algae are extremely toxic to human beings and animals. F. Eichhornia crassipies is the world's most problematic aquatic weed.

Make a list of impurities present in domestic sewage.

Assertion : BOD of river polluted by sewage is more than 20 ppm. Reason: Polluted river contains excess of organic matter.

Assertion : BOD of river polluted by sewage is more than 20 ppm. Reason: Polluted river contains excess of organic matter.

Assertion: Discharge of sewage into river results into a sharp details in disolved oxygen Reason:- Micro-organisms invovled in biodegradation of organic matter in the reciving water body produce a lot of oxygen to facilitate degration of organic matter.

Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microoganisms ionvolved in biodegradation or organic matter in the receiving water body consume a lot of oxygen.

Assertion : There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Reason : Microoganisms ionvolved in biodegradation or organic matter in the receiving water body consume a lot of oxygen.