What is water pollution?
Water pollution happens when there is a significant amount of substances are released into subsurface groundwater or into water bodies such as oceans, estuaries, rivers, streams, and lakes to an extent where the substances impact and interrupt the usefulness of the water or with the natural composition of the water and the surrounding ecosystem.
Apart from certain substances such as microorganisms, trash, and chemicals, water pollution is also caused by a release of energy in either heat or radioactivity into water bodies. Therefore, when water bodies get polluted, they negatively impact all life forms that either directly or indirectly depend on those sources. The consequences of water pollution can last years and years.
Sources of water pollution and Types of water pollution
Water bodies are polluted by various factors and substances, including fertilizers and plant nutrients, toxic chemicals, sediments, putrescible organic Waste, pathogenic microorganisms, heat, petroleum and radioactive substances.
Water pollutants’ origin can be classified into dispersed or point sources, the latter being a point from which the substances are directly discharged into the sewage system. A dispersed source is an unconfined area from which a variety of water pollutants may originate. Some of the origins of water pollutants are listed below:
- Domestic sewage: some of the most prominent disease-causing pathogens, microorganisms and putrescible organic substances are found in domestic wastewater. And this leads to a significant threat to public health. The organics present in the sewage are decomposed by bacteria naturally, resulting in a reduced level of oxygen content. It impacts the quality of life in the lakes and streams as organisms require high oxygen levels. Domestic sewage also leads to excessive algae production, sometimes known as algal blooms, because they are a potent source of nutrients, such as nitrates and phosphates, which result in excessive growth of organisms like Algae.
- Solid Waste: When solid Waste is not disposed of properly, it leads to significant water pollution. Solid Waste can include electronic Waste, garbage, demolition, and construction waste, produced by institutional, industrial, commercial and residential activities. In addition, land pollution can often turn into water pollution if the debris or trash is carried over by wind, rainfall or animals’ land in the water.
- Solid Waste pollution is significantly harmful to aquatic ecosystems’ health and can directly harm wildlife. Solid Waste, such as electronic waste and plastics, can leach harmful and dangerous chemicals into the water bodies, making them hazardous and toxic.
- Toxic Waste: any waste that is explosive, radioactive, poisonous or carcinogenic, mutagenic, teratogenic, or bio-accumulative is considered toxic. Toxic Waste can come from wastewater from industrial plants and chemical process facilities that are not disposed of properly, as well as runoff that contains pesticides used in agricultural lands and lawns.
- Sediment: surface runoff can also cause soil erosion and other construction products to run into water bodies. This sediment suspended on the surface of the water can disrupt the penetration of sunlight and disbalance the water body’s ecology.
- Thermal pollution: Temperature changes can also act as pollutants; heat, for instance, can be a water pollutant, as it lowers water’s capacity to contain dissolved oxygen in solution and simultaneously enhances fish’s metabolism. Many marine organisms cannot survive in low levels of oxygen in the water. In addition, heat is usually produced by cooling water discharged from power plants into rivers.
- Petroleum oil pollution: petroleum pollution happens as a result of oil from lands and roads running into water bodies. Oil spills are an example of this. Accidental oil spills are a huge source of oil pollution.
Effects of Water Pollution
on groundwater: water beneath the surface is a drinking water source for many people worldwide. Although groundwater undergoes filtration of several layers as it passes through the soil, it still contains pollutants, including dissolved chemicals, bacteria and viruses. It can be harmful in areas where the subsurface sewage disposal system is not maintained correctly.
In addition, industrial wastes that are not disposed of properly, petroleum and mining production, and leaking underground storage tanks of gasoline stations can all contribute to contaminated groundwater.
On Oceans: although oceans are vast, their ability and capacity to absorb pollutants are constrained. Seas can be contaminated by sewage outfall pipes, the dumping of wastes and sludge, and oil spills. Oil spills, in particular, can severely impact marine life, which, in turn, can affect the ecosystem of the entire aquatic region.
Dangerous and toxic waste materials can also travel back to the shore, making beaches hazardous. Studies have shown that by 2010, about 4.8 million and 12.7 million tonnes of plastic debris were dumped into the oceans yearly.
Water Pollution can also significantly impact the food chain as it disrupts Toxic substances such as cadmium and lead into the food chain via animals and then disrupts it at higher levels.
Water pollution also severely impacts humans directly, who can contract diseases through faecal matter in the water, such as Hepatitis B. Poor treatment of drinking water can also lead to conditions such as cholera which are infectious.
Controlling Water Pollution
Although we have significantly polluted our water bodies, there are particularly effective ways to control water pollution. Instead of releasing sewage waste directly into the water bodies, we should treat them before discharging them into the water. It will prevent the initial toxicity, and the decomposition of the remaining substances can happen in the water body.
If the water has been treated in secondary treatment, it can be reused in agriculture fields and sanitary systems. Additionally, water hyacinth, a plant, has been known to absorb toxic chemicals dissolved in water, such as cadmium and others. Planting these in regions affected by water pollution can help decrease the effects.
There are chemical methods as well that help the curbing of water pollution. They include precipitation, reverse osmosis, coagulation, and ion exchange.
At the individual level, we can help curb water pollution by reusing recycling and reducing it as much as possible to help curb water pollution in the long run.
Management of erosion and soil erosion and sediment control is another effective way of curbing pollution in water bodies. It can be done by installing erosion controls, such as hydroseeding, mulching, and sediment controls, such as silt fences and sediment basins.
Stormwater management: if we learn to manage stormwater which flows along the sides of lawns, streets and sidewalks and picks up harmful chemicals and pollutants that are then drained into the streams and rivers, we will be able to curb water pollution to some extent. Stormwater can be managed through treatments in a variety of processes, including electrocoagulation and sand filtration, reverse osmosis, etc.
Green agriculture: Since the agricultural sector deploys 70% of surface water, it should also be able to manage that water without causing water pollution. However, pesticides and fertilizers are an important cause of water pollution as they run off into the water bodies, taking viruses and bacteria along with them. Therefore, to enact green agriculture, one has to plant more trees near water bodies, preventing water from running into the water bodies.
Denitrification: denitrification is one of the most simple processes that can help convert nitrates into nitrogen gas, preventing nitrates from being absorbed into the soil and contaminating groundwater. A high nitrate level can cause algae and phytoplankton to grow continuously in water bodies.
In conclusion, water pollution is caused when the natural composition of a water body or ecosystem is altered by substances or releases of energy that come from human civilization. Humans are the primary agents responsible for causing water pollution. A contaminated or polluted water body can lead to several dangerous consequences, including human health and life, disruption of natural ecosystems and food chains and a disastrous impact on the earth’s future.
What are some of the most important causes of water pollution?
Water pollution is caused by various factors, including agricultural runoff, urbanization, industrial activities, religious and social practices, accidents such as nuclear fallout, oil spills etc.
What are some of the most critical steps in sewage treatment?
There are four primary steps in wastewater treatment, namely:
2. primary treatment
3. secondary treatment
4. final treatment
What are inorganic contaminants?
Inorganic pollutants in water include heavy metals that come from motor vehicles, Ammonia that comes from food processing waste, phosphates and nitrates that come from agricultural and sewage, and silt that is runoff from construction sites or sewage logging and land clearing sites. Salty runoff also contaminates freshwater bodies.