Excessive inhalation of manganese causes:

The $BOD$ limit prescribed by the Central Pollution Control Board $(CPCB)$ for the discharge of industrial and municipal wastewater into natural surface water bodies is .....

The secondary pollutant that inhibits the Hill reaction is:

The addition of elements like nitrogen and phosphorus to a lake through streams leads to:

$A$: Taj Mahal is being destroyed by $SO_2$ coming from Mathura refinery.
$R$: This converts $CaCO_3$ into unstable calcium sulphate.

Define/Explain the following terms:
$(i)$ Eutrophication
$(ii)$ Jhum cultivation