LEARNING OBJECTIVES
In this article, the author has explained what is water pollution, Types of water pollution, causes of water solution and solution of water pollution.
Water is an essential for the life on earth. Water is essential part of every living organism. In order to maintain life every human being drinks several liters of water daily. Natural life is impossible without water.
What is water pollution?
Table of Contents
Surface water and ground water are the vital sources of fresh water for plants and animals. When the pollutants released by human and natural activities is mixed in water resources it becomes unhealth for living organism and doemstic purposes. This contamination of water in known as water pollution.
Causes of water pollution
The human society is based on human activities. All the activities are responsible for the contamination of water. These activities are as follows.
- Livestock waste
- Landfills
- Agriculture
- Pesticides
- Oil leaks
- Spills disposal of industrial effluents on open land
- Water bodies
- Septic tanks
- Mining
- Petroleum and natural gas production
Let us discuss all of these activities one by one in detail.
1: Livestock waste and water pollution
Livestock waste is damped on open land. Sometimes it is directly discharged into sewage, canals or rivers. This practice pollutes the surface and ground water. In this way serious problems are created for the population.
Bacteria is present in the livestock waste. It contaminates the surface and ground water. Due to this contamination many diseases are caused such as…
- Dysentery
- Typhoid
- Hepatitis
2: Oil spillage
Petroleum is one of the highly used thing on the planet. The world heavily It is a complex mixture of many compounds which are mainly hydrocarbons. It is transported from one place to another through sea.
Hydrocarbons and animal life
Many petroleum products are poisonous and create serious health problems to humans, animals and aquatic life.
Polycyclic hydrocarbons are carcinogenic even at very low concentration. Marine animals are seriously effected by soluble aromatic fractions of oil. The spilled oil damages the feather of the birds or fur of the animals and sometimes causes their death.
Following are the products of petroleum obtained after fractional distillation are used in making following products…
- Fuel
- Lubricants
- Manufacture of petrochemicals
- Plastics
- Electrical appliances
- Synthetic rubber
- Detergents
In order to prepare such a large varieties of substances, petroleum is handled on large scale in the world. So, the oil spillage can take place and it creates serious problems.
Pollution of water by petroleum
The largest petrol reserves are found in the bottom of the sea around the world. Water gets polluted by the petroleum in following ways…
- Accidental oil spills
- Leakage of petroleum from the cargo oil tankers in sea
- Leakage of tanker trucks
- Leakage of petroleum transporting pipe lines during offshore exploration
- Leakage of underground storage tanks in urban areas
Effects of Petroleum and aquatic life
The havocs of petroleum pollution are not limited to human being, but it also affects the aquatic life as well. When oil is spilled on the surface of sea then the light transmission is affected. The process of photosynthesis of plants does not remain that much efficient. Moreover, the concentration of oxygen in water is also decreased. This limited supply of oxygen affects both aquatic plants and fishes.
Many petroleum products are poisonous. When industrial waste is dumped into rivers and sea, these kills the fishes and other aquatic organisms.
3: Detergents
Definition of detergents
Detergents are the sodium salts of benzene sulphonates and are used as the cleaning agents in household and industries.
Detergents are the surfactant compounds. These compounds lower the surface tension of water and increase the wetting ability of water. The water can go into the fabric and cleaning action is improved.
Types of surfactants
There are various types of surfactants:
- Anionic surfactants
- Cationic surfactants
- Amphoteric surfactants
The most common types of surfactants are sodium salts of sulfates or sulfonates.
Those compounds which increase the function of detergents are called builders. The important builders are sodium tripolyphosphate. These release the phosphate ions in water which make soluble complex with Ca+ and Mg+.
Surfactants, builders and water pollution
Both the surfactants and builders are responsible for water pollution. These create a threat for aquatic life.
Nitrolo acetic acid is being used as a substitute of phosphate. Anyhow, it is also health hazard. It mobilizes heavy metals such as Pb, Cd, and Hg from sediments into water.
4: Pesticides
Definition of pesticides
Those substances which can directly kill an unwanted organism or control by interfering with its reproduction process are called pesticides.
Pests harms the crops and transmit different diseases both to humans and animals.
The question arises here is that why we use pesticides?
Well the answers is quiet simple. To feed the ever growing population we can produce the large amount of food on relatively small area of land by using pesticides.
Types of pesticides
There are more than ten thousand synthetic organic pesticides which have been formulated. There are several principal types according to their general chemical nature.
ii) Insecticides
these pesticides are used to kill insects
ii) Herbicides
These pesticides are used to kill undesired plants
iii) Fungicides
These pesticides are used to control the growth of fungus on the plants.
Pesticides and eradication of diseases
Various pesticides have been used for eradication of following diseases:
- Malaria
- Yellow fever
- Bubonic plague
- Sleeping sickness
Moreover, the pesticides boost up the crop production.
Pesticides and contamination of soil
When pesticides are used excessively then there is a possibility of greater crop yield. Anyhow, if this use is not properly checked and controlled then the soil is contaminated along with plants and water.
Following are different aspects in respect of pollution due to pesticides.
- Pesticides are used for agriculture. The drainage water from agriculture land has pesticides in it. This water transports the pesticides to those places which are still free of pollution.
- The agricultural food products and the drinking water is affected by the pesticides.
- Chlorinated hydrocarbons are not degradable. These remain in the environment for a very long period. This environment is consisted of soil, water and plants
- DDT is one of the most powerful insecticide. Its chemical name is para-dichlorophenyl dichloromethane. There was a time when it was widely used. In these days it is thought to be carcinogenic and therefore, its production has been banned in many countries.
- All the pesticides re poisonous.
- All the pesticides have serious health problems for human being and animals.
Organic chemical in drinking water
Organic chemicals join our fresh water resources by multiple ways. There are some organic chemicals which do not have invisible effect at lower concentration.
Anyhow, some synthetic organic chemicals have serious and great health hazards even at lower concentrations. This low concentration may be 10 parts per million or even below that.
Some of the organic chemicals are tasteless and odorless even at higher concentrations.
There are many light molecular weight chlorinated hydrocarbons in drinking water which are carcinogenic and they do not have any safe level. For this reason these cannot be consumed through the air, food or water without the risk of adverse health effects.
Effects of chlorinated hydrocarbons on human health
Synthetic organic chemicals including chlorinated hydrocarbons can cause the following health problems.
- Nausea
- Dizziness
- Tremors
- Blindness
- Skin eruptions
- Effect on central nervous system
One should be careful that when such compounds are taken in low concentration then there is a long period of time between exposure and the appearance of the disease.
5: Industrial waste effluents
Following are some important industries whose industrial wastes cause pollution. These industries are as follows:
- Leather tanneries
- Fertilizers
- Oil refining
- Petrochemicals
- Textiles
- Paper pulp and paper
- Rubber products
- Agrochemicals
- Leather goods
The waste products which are obtained from these industries may be in the form of waste heat, smoke and solid or waste water effluents.
Smoke of industries
Smoke and all other pollutants present in the air cause air pollution and are settled to the soil. These go to surface water through precipitation. These also reach the surface of earth by acid rain and contaminate the ground water. If these gases are not properly controlled then the air, soil and water are contaminated.
Metal pollutants of industries
Industrial waste pollutants may contain organic chemicals which include highly toxic synthetic organic compounds. Followings are some of the heavy metals which are present in the waste.
- Pb
- Cd
- Cr
- Hg
- As
- Sb
Anyhow oils, greases and mineral acids are also there. All these things contaminate both surface and ground water. This water is used for irrigation and drinkable water supply.
These things also cause irreversible degradation of environment.
Effects of industrial water pollution
The heavy metals are highly toxic and do not have any safe things. These are the following diseases that are caused by these toxic metals in water.
- Anemia
- Kidney disease
- Nervous disorder
- High blood pressure
- 6: Leather tanneries
There are many leather tanning units working all around the world. Their sizes vary from small to large scale industrial units.
Leather industries use chromium salts which have +6 oxidation state of chromium. Only a few industries have the facility of waste water treatment. This is done by reducing Cr+6 oxidation state to Cr+3 oxidation state. Cr+3 is precipitated as Cr(OH)3. Cr+6 salts are highly toxic and cause cancer.
Solution of water pollution
Water can be purified by using multiple ways.
- Boil the water for drinking purpose
- Use different water filters
- Use charcoal for water in pots
- Use chlorination method for purifying water for drinking and agriculture purposes.
- Allow the water to stay in large tank for several hours in order to remove larger physical pollutants