Water Pollution: Causes And Human Impact

Water pollution is a pressing global issue that poses a threat to human health, wildlife, and the environment. It occurs when harmful substances contaminate water bodies, degrading water quality and rendering it toxic and unsafe for human use. Water pollution can happen through various human activities, such as industrial waste discharge, agricultural runoff, sewage and wastewater treatment, oil leaks and spills, radioactive waste, and plastic pollution. These activities introduce toxic chemicals, microorganisms, and debris into water sources, endangering aquatic ecosystems and human health.

Industrial waste

The production of industrial goods generates wastewater that can be contaminated with these toxic substances. In some cases, this wastewater is discharged untreated into nearby public waters, such as rivers, lakes, and seas. This is particularly common in emerging countries with a growing number of industrial plants, such as China, India, Africa, and South America.

The consequences of industrial wastewater pollution are severe. Many hazardous substances from industry are difficult to biodegrade and accumulate in water sediments. This can lead to illness and death among fish, crustaceans, and other aquatic creatures, disrupting biodiversity. Additionally, polluted water from rivers and contaminants from water sediments can enter groundwater, affecting drinking water supplies.

To prevent water pollution from industries, it is crucial to implement appropriate environmental legislation and ensure compliance through new technologies that enable companies to adopt sustainable and economical industrial wastewater recycling systems.

Marine dumping

The ocean is the basin that catches almost all the world's water. Water evaporates from the ocean, leaving salt behind, and becomes rainfall over land. Water from melted snow ends up in rivers, which flow through estuaries and meet saltwater. Fertilizers, pesticides, and oil, mostly from farms, seep into the ground after rainfall and eventually stream into the ocean. This encourages algal blooms that clog up waterways, causing meadows of seagrass, kelp beds, and entire ecosystems to die. These "dead zones" can be the size of entire states, and all major bays and estuaries now have them due to pollution runoff.

Sewage and wastewater

More than 80% of the world's wastewater is released back into the environment without any treatment, according to the United Nations. This untreated wastewater contains a variety of harmful substances, including pathogens, pharmaceuticals, microplastics, heavy metals, and endocrine disruptors. These contaminants pose a serious risk to both the environment and human health, threatening aquatic life, food and water security, and public health.

Inadequate wastewater treatment can lead to habitat loss, extinction, and the introduction of toxic substances into the water. It is important to recognize that sewage treatment plants are not the actual source of pollution, as they treat the wastewater generated by human activities. The main sources of sewage pollution are incorrect disposal practices, such as flushing wipes, nappies, or cotton buds down the toilet, and pouring cooking fats, oils, and grease down the drain. These actions can cause drain blockages and flooding, leading to environmental pollution. Additionally, misconnections, resulting from incorrect plumbing, can pollute waterways by connecting drainage from a building to the wrong sewer network.

To address sewage and wastewater pollution, it is crucial to raise awareness, implement proper waste disposal practices, and advocate for improved wastewater treatment systems and infrastructure. By taking these steps, we can minimize the impact of sewage and wastewater pollution on our environment and protect our valuable water resources.

Oil leaks and spills

Oil spills can result from the release of crude oil from tankers, offshore platforms, drilling rigs, and wells, as well as refined petroleum products such as gasoline and diesel fuel. They can also involve spills of heavier fuels used by large ships, such as bunker fuel, or any oily refuse or waste oil. These spills can have severe environmental consequences, particularly for local marine wildlife such as fish, birds, and sea otters. Oil forms a thick sludge in water, suffocating fish, impairing the movement of marine birds, and blocking light from reaching photosynthetic plants.

The cleanup and recovery process after an oil spill is challenging and can take weeks, months, or even years. It depends on various factors, including the type of oil spilled, the temperature of the water, and the types of shorelines and beaches involved. Physical cleanups can be expensive, and chemical remediation is often required to break down or remove the oil.

Oil spills can also have negative impacts on human health, including respiratory and reproductive problems, liver damage, and immune system issues. They can contaminate drinking water supplies, leading to the spread of dangerous diseases. Additionally, oil spills can disrupt tourism and marine resource extraction industries, causing economic losses for the affected regions.

To prevent and mitigate the impacts of oil spills, regulations and safety measures have been put in place, such as the Oil Pollution Act of 1990 in the United States, which holds responsible parties accountable for cleanup and restoration costs. However, despite these efforts, oil spills continue to occur and pose a significant threat to our oceans and coastal ecosystems.

Radioactive waste

There are several treatment technologies available for radioactive wastewater, each with its advantages and limitations:

• Ion Exchange: This method uses ion exchangers to separate and extract specific ions from the wastewater. It is suitable for treating low-salt wastewater and is often used for low-level radioactive waste.
• Chemical Precipitation: A simple and cost-effective method that involves co-precipitating the radionuclides with a precipitant to reduce their specific activity. However, it has limitations in treating anionic radionuclides and can be challenging to separate solid-liquid post-treatment.
• Evaporative Concentration: This method evaporates water from the wastewater, leaving behind the non-volatile radionuclides for further treatment. It has a high decontamination coefficient and volume reduction capability but consumes a lot of energy.
• Membrane Separation: This method uses selective membranes to separate, purify, and concentrate the wastewater. It is flexible and has a high purification coefficient but requires high-quality raw water and is prone to membrane fouling.
• Adsorption: This method uses adsorbent materials to remove radionuclides from the wastewater. It offers high selectivity and simple operation but can be costly and challenging to regenerate the adsorbent materials.
• Biotechnology: This approach uses plants or microbial cells to remove radionuclides through various mechanisms. It is environmentally friendly and cost-effective but has limited applications due to the sensitivity of microbes to radiation.
• Photocatalysis: This method uses solar energy to chemically change the reactants, allowing for the treatment of organic wastewater. However, it has limited applications in natural uranium-containing wastewater due to low charge separation efficiency and sunlight utilization.

Combining multiple treatment processes can enhance their effectiveness and address their individual limitations. Integrated radioactive wastewater treatment equipment is becoming an attractive solution, offering lower investment, simpler operation, and flexible water reuse options.

Frequently asked questions