In general pollution is anything hat negatively impacts the environment. Warming of the water by introducing a warm effluent:
This is called thermal pollution because it raises the water temperature of the river above its normal value.
water pollutant
Every chemical that goes to rivers and lakes are water pollutants.
Detergents are not considered as water pollutants since the use of phosphates in detergents was outlawed.
these have more water in those days
This is one example of water pollution. Water pollution can be accidental or intentional, and could include oil, sewage, dyes, or any kind of other chemical that is not supposed to be there. In some cases, very hot or cold water can even be considered a kind of pollution.
No. Water vapor occurs naturally and is harmless, and is needed for precipitation. ********************* It could be argued both ways. Water vapour is considered a pollutant by people because of its apparent 90% contribution to the natural greenhouse effect. Though this may be the case, water vapour is, well, simply that: water vapour. It is what turns into rain, and rain is good. So both ways, rain could be considered a pollutant or not.
Water pollution can be pollutant if the polluted water floods to places of human residences.
the runoff of the rainfall from the land into rivers and the sea.
Pollutant
The discharge of a river is the discharge that the river puts out into the sea. This is often the finer silt that the river has picked up and carried from the upper and lower reaches of the river.
Water is used to produce energy by letting it flow. This form of energy is called hydroelectric power and is considered non-pollutant.
The pollutant is acid rain