Question

how does the river water gets polluted ?​

Answer 1

Answer:

Fertilizers and pesticides are harmful because they cause algae to grow. The algae then destroy water plants. Factories use water from rivers to power machinery or to cool down machinery. Dirty water containing chemicals is put back in the river.

Answer 2

Explanation:

Dirty water containing chemicals is put back in the river. Water used for cooling is warmer than the river itself, and this is also a form of pollution. People are sometimes careless and throw rubbish such as bottles and crisp packets directly into rivers. Pollution kills water plants and animals.