Question

define
water polution​

Answer 1

$\bold\red{Water\: pollution :- }$$<i><b>$Water pollution is the contamination of water bodies, usually as a result of human activities. Water bodies include for example lakes, rivers, oceans, aquifers and groundwater. Water pollution results when contaminants are introduced into the natural environment . Water bodies include for :- example lakes, rivers, oceans, aquifers and groundwater. Water pollution results when contaminantsare introduced into the natural environment. For example, releasing inadequately treated wastewater into natural water bodies can lead to degradation of aquatic ecosystems .

Answer 2

$\huge {\bf{\blue{Water \:Pollution}}}$

Mixing of harmful substances such sewage, toxic chemicals, silt, etc. with water, is called water pollution. The substances that pollute water are called water pollutants. Water becomes dirty after we as use it for washing clothes, bathing, cleaning utensils, etc. This means that something is being added to water, which spoil its quality and change its smell and colour.

Besides being polluted, usable water is becoming scarce due to increase in population, industries and agricultural activities. The enormous amount of water in the oceans is not usable, and is unfit for consumption by human, animals and plants and even industries.

$\bf{\green{How\: does\: Water\: Get\: Polluted?}}$

Our main sources of drinking water and usable water are rivers and lakes and underground water. When rivers and lakes are polluted, their polluted water aslo reaches underground by seeping through the ground. The main reasons for the pollution of water in our rivers and lakes are the following.

1. Discharge of untreated sewage into rivers and lakes : The untreated domestic domestic sewage contains food wastes, detergent, faeces urine, such as bacteria, fungi, viruses, protozoa and parasites. These microorganisms may cause diseases like cholera, jaundice, typhoid, microganisms etc.

2. Discharge of toxic industrial wastes into rivers and lakes : Industrial units discharge toxic chemical wastes such as fertilizers, detergent, pesticides and dyes along with various acids, alkalies and salts and toxic metals such as lead and arsenic.

3. Excessive use of fertilizers and pesticides in agriculture : Residual fertilizers and pesticides dissolve with rainwater and reach rivers and lakes. These all pollutants make the water coloured, foul smelling, bad in taste and sometimes poisonous.

$\bf{\green{Harmful \:Effects\: of\: Water\: Pollution}}$

Polluted water has many germs which cause many diseases like cholera, dysentery typhoid, hepatitis (jaundice), diarrhoea and skin diseases. Various industrial chemicals in polluted water harm both aquatic animals and human beings very much.

Eutrophication : The excessive quantities of chemicals (fertilizers) which get washed from the fields, act as nutrients for weeds like algae to flourish in water. Once these algae die, they serve as food for decomposers like bacteria. These weeds consume most of the dissolved oxygen. The deficiency of oxygen in the water may kill other aquatic organisms like fish. This loss of dissolved oxygen from water in water bodies is called eutrophication.