Current Concern Of Water Pollution: Types, Causes And Methods To Reduce
Introduction
Water is necessary for all living organisms. There is always the chance of the presence of any form of life on the planet which contains water. The exponential increase in the world’s population has drastically increased the consumption of water. The world population is expected to reach 9. 7 billion in 2050, according to a new UN DESA report, “World Population Prospects: The 2015 Revision”. This growth in population combined with sanitation and industrialization will result in an increased consumption of water and will have bad effects on the environment. About two third of the Earth’s surface is covered with water; However, most of the water cannot be used for drinking purposes because of too much salt present in it. Only 2. 5% of the world’s water is fit for drinking, and 1. 7% of it is frozen in the glaciers, and the ice caps of Antarctica and Greenland.
Water pollution is one of the major problems of the Earth. According to the millennials who participated in World Economic Forum's Global Shapers Survey 2017, food and water security is the 7th most critical problem of the Earth. The effects of water pollution on human health if we put it bluntly: Water pollution kills. In fact, it caused 1. 8 million deaths in 2015, according to a study published in The Lancet. Contaminated water can also make you ill. Every year, unsafe water sickens about 1 billion people According to the United States Environmental Protection Agency (U. S. EPA) About 700 million people globally drink contaminated water. Aquatic animals face an extinction rate of five times more than that of terrestrial animals. At least 320 million people in China do not have access to clean drinking water.
Water pollution is defined as the presence of excessive amount of harmful contaminants that changes the water physically, chemically, and biologically that it is no longer safe for drinking, cooking, bathing or other uses. Groundwater is an essential source of freshwater for fulfilling the water demands of agricultural, domestic, industrial and other sectors as well as maintaining ecosystems in many countries all over the world. But the rapid increase in industries, unfair utilization, lack of proper sanitation, and planning for maintaining the availability of water in case of any crisis have led us towards the situation where the world is now facing the big threats for sustaining the freshwater resources. According to WWAP about 2 million tons of waste including Industrial, agricultural waste, and sewage is disposed of in water. Unable to provide proper sanitation is one of the major causes of contamination of freshwater resources. Around 2. 5 billion people are spending their lives with spoiled and outdated sanitation; Furthermore, around 844 million humans around the world are compelled to drink unsafe water. In addition to this, the health of half of the developing world is endangered because of utilizing polluted water. A survey shows that about 80% of the untreated wastewater is discharged into the sea or lakes. Because of this, deaths due to waterborne diseases have been drastically increased. Now, worldwide waterborne diseases are becoming major reason of deaths of children younger than 5 years; Moreover, drinking of unsafe water is becoming the reason of deaths annually more than all types of violence combined including war. Drinking unhealthy and polluted water, improper sanitation, and bad hygiene are causing worldwide around 3. 1 percent of all deaths daily. This discharged waste-water is not only affecting the human health but also causing harm to the aquatic life and eco-system. Around 50% of the freshwater species are now categorized as endangered species, and around 33% amphibians are at the risk of extinction. Extinction rate on the freshwater species is five times greater than the earthborn species.
Types of Water Pollution:
lthough groundwater and surface water are considered as two different freshwater resources but they are interrelated. Sources of water pollution on the basis of their origin are mainly classified into two types.
- Point source pollution
- Non-Point Source Pollution
Point source pollution refers to those pollutants whose direct sources can be identified. Examples of such types of pollution include industrial discharges from the industries, oil leak from a tanker, wastewater effluents, and storm sewer discharge.
Non-Point source pollution is caused by the addition of contaminants in water which does not originate from a single source. It occurs when the water from rainfall, snowmelt or from other human activities such as irrigation of crop, maintenance of garden and lawns flows across or under the land it picks up pollutants (natural or artificial) which can be deposited in the freshwater resources like lakes, rivers, and coastal waters. The discharge of different compounds of nitrogen from fertilized agricultural areas is a typical example of non- point source pollution.
Causes of Water Pollution
Pollution of water is caused by various sources. Industrial, agricultural and houses are the three major sources of water pollution. Major causes of water pollution are discussed below:
- Industrial waste: Industries due to different chemical and manufacturing processes produce a large amount of solid and liquid waste, which contains toxic chemicals and heavy metals. These chemicals possess the ability to change the color and chemistry of water, which is also known as Eutrophication and can pose serious damage to the organisms living in water.
- Oil Spillage: Accidental leakage of oil into the sea from cargo ships, and tankers carrying petrol, diesel, and derivatives are one of the major causes of water pollution. Extraction of oil near the coastal areas also lead to oil pollution in water. A large amount of oil does not dissolve into the sea and forms a thin layer on the surface of the water, which results in damaging not only fishes but birds and other living organisms whose life is dependent upon the sea.
- Sewage and Wastewater: The sewage and wastewater from houses and industries are beyond control. Annually 1500km3 of wastewater is produced, six times more water than exists in all rivers around the world. (UN WWAP 2003). Over 80% of all wastewater produced annually is discharged into the sea without any proper treatment. The wastewater from sewage contains harmful chemicals that affect all the living organisms include fishes, birds and, humans. Microorganisms in the wastewater can cause serious diseases also act as carriers of other diseases. Malaria is the common example of waterborne disease.
- Agricultural Wastes: Herbicides, pesticides, and fertilizers are the major constituents of wastewater from crop fields. Due to the increase in population, the demand for food has also increased. To fulfill these demands from limited crop fields use of different fertilizers, and herbicide has also been increased. The consumption of fertilizers has been extremely increased from 20 Tons to 100 Tons from 1967 to 2009. Most of them are non-biodegradable and stay in the water for a longer time and pose serious damage to aquatic life.
- Urbanization: This happens when humans decide to expand their cities to uninhabited areas of the environment to meet the increasing demand for houses. This results in the increase in soil erosion due to deforestation, increase in the construction activities, inadequate sewer, increase in the use of fertilizers for crop production, landfills as more garbage is produced, increase in chemical consumption and drainage for producing more material.
- Marine Dumping: It is the disposal of solid waste or other matter including food, paper, plastic, glass, rubber, and aluminum in the sea. Approximately 2 to 200 years are required to decompose this foreign matter. It causes serious damage to the marine life and their habitat. It can also affect the health and fertility of marine environment by erosion of coastal areas.
- Radioactive Waste: Radioactive Pollution is the result of the presence of any type of radioactive material in the water. If the rate of uptake of radioactive nuclides is high then it can cause serious damage and in some cases genetic mutation e. g. Radium can cause cancer, but Uranium can also affect the kidneys. The sources of radioactive waste are waste of nuclear power plants, water used in nuclear plants, radioactive sediments, lack of care during handling of radioactive minerals.
- Animal Waste: Waste of animals washed during rainfall and irrigation of land and enter into the freshwater reservoirs without any treatment. It causes serious damage to the chemistry of water and also become the cause of waterborne diseases like diarrhea, dysentery, jaundice, and typhoid.
Methods for Reducing Water Pollution
Water pollution is one of the major concerns of humanity nowadays. Different International and national organizations like Pacific Institute, World Water Council, Charity-Water, United Nations, and many others are working on providing awareness, and funding projects for developing methods to reduce the current concentration of pollutants in freshwater resources, and also to minimize their further addition. There are three major sources of water pollution i. e. Municipal, Agricultural, and Industrial sectors. Reducing the use of plastic bags, promoting the use of Biodegradable plastics, introducing recyclable materials, developing environment-friendly detergents and dishwashers, running campaigns for planting trees are examples of some steps taken to reduce water pollution at the municipal level. Similarly, in the Agriculture sector, these organizations are providing awareness to the farmers about this problem, promoting the culture of smart farming among the farmers. With the help of smart farming, the farmer can measure the amount of water given to the plant, determine the specific nutrition need by the soil, and can also determine the best crop to plant on the specific area according to the condition of the soil. Sustainable intensification, a newer technique, seeks to extend the production of crop whereas minimizing the pressure on the atmosphere.
With the application of smart farming technology farmers can minimize the excessive use of water, pesticides, and fertilizers. At the Industrial level, various steps have been taken to decrease water pollution, this includes optimization of the processes for minimizing the use of chemicals and production of wastewater. Different minimization techniques have been developed to reduce the consumption of water, as well as recycling of wastewater. A researcher applied reduction techniques in a woolen textile mill as a result 41-69% reduction in water consumption and 48-75% reduction in wastewater production is observed.
A group of researchers developed a Monte-Carlo based integrated model to enhance the control of industrial wastewater pollution and to improve the quality of water. Luana Morena Rodrigues applied various techniques on a fish processing plant in Brazil to reduce the liquid effluent generation and consumption of water. The results show the reduction in water consumption was 10. 3% which can further increase to 15. 92% by the recycling of effluents.
Different projects have also been patented to reduce the water pollution. A project patent by Edmund J. , Patent number # US4676908A, in which they enhance the capability of Wastewater Treatment plants for removing soluble organic materials from the wastewater to increase the purity level of water and to eliminate the treatment of wastewater with ozone.
