Water Pollution's Impact On Our Bodies Of Water

Water pollution is a pressing issue that affects various bodies of water, including rivers, lakes, oceans, aquifers, reservoirs, and groundwater. It occurs when harmful substances contaminate these water sources, rendering them toxic and unfit for human use or ecological systems. The main sources of water pollution are sewage discharges, industrial and agricultural activities, and urban runoff, such as stormwater. These activities introduce contaminants like toxic waste, petroleum, chemicals, and disease-causing microorganisms into the water, degrading aquatic ecosystems and spreading waterborne diseases. This form of pollution poses significant risks to human health and the environment, making it a global challenge that requires urgent attention and effective solutions.

Sewage and wastewater

The four main types of wastewater are domestic, industrial, agricultural, and urban. Domestic wastewater consists of black water containing human and animal fecal matter, as well as greywater from household activities like bathing, washing, cooking, and gardening. Industrial wastewater consists of industrial waste like pulp, paper, petrochemical runoff, chemicals, salts, and acids. Agricultural wastewater comes from agricultural activities, contaminated groundwater, and farming techniques, especially those related to fertilizers and pesticides. Urban wastewater is a combination of domestic and industrial wastewaters, combined with sewage infiltration and rainwater.

Wastewater treatment has three phases. The first phase, or primary treatment, places the wastewater in holding ponds. Solid waste settles at the bottom, and low-density materials like fats and oils float to the top. These materials can then be removed. The second phase or secondary treatment removes dissolved and suspended biological material. Most secondary treatment systems use aerobic bacteria to consume organic material in the wastewater. Tertiary or third-phase treatment further cleans wastewater that will eventually be released into sensitive environments. Despite the Clean Water Act of 1972 requiring secondary treatment of wastewater, some U.S. municipalities filed and received exemptions.

According to the United Nations, more than 80% of the world's wastewater flows back into the environment without being treated or reused. In some least-developed countries, this figure tops 95%. Inadequate management of urban, industrial, and agricultural wastewater means the drinking water of hundreds of millions of people is dangerously contaminated or chemically polluted.

Biological hazards found in wastewater include bacteria, fungi, parasites, and viruses. Bacteria and bacterial diseases range from E. coli, typhoid fever, salmonella, cholera, and shigellosis. Fungi include aspergillus. Parasites include cryptosporidium, giardia, and roundworms. Viruses like hepatitis A can also be found in wastewater. An estimated 3.5 million Americans get sick from recreational activities like swimming and boating each year due to contaminated water.

Nutrient-rich materials from fertilizers, especially nitrogen and phosphorus, and waste material cause eutrophication in both fresh and marine ecosystems. Algal blooms from the excess of nutrients decrease light transmission in the water, impacting plants and plankton while reducing the amount of oxygen in the water. As the algae die, decomposer bacteria consume even more of the dissolved oxygen, creating "dead zones" where aquatic life cannot survive due to a lack of oxygen.

Industrial waste often passes through the same sewer treatment facilities as domestic waste. Industrial waste often contains a variety of chemicals and may also contain heavy metals like lead, mercury, cadmium, and arsenic. Not all of these chemicals are completely removed in sewage treatment plants, so they are released into rivers, lakes, and marine waters.

##

Plastics and garbage

Plastics and other garbage are a major source of water pollution, with plastic waste being one of the most pressing environmental issues. Plastic pollution is most visible in developing Asian and African nations, but it is a global problem. Every year, about eight million tons of plastic waste escapes into the oceans from coastal nations. This is the equivalent of setting five garbage bags full of trash on every foot of coastline around the world.

The production and use of plastic are widespread, with plastic being used in almost all consumer and industrial activities, from construction and vehicles to electronics and agriculture. Single-use plastics, in particular, are a major contributor to plastic pollution, with items such as plastic bags, bottles, caps, cigarettes, shopping bags, cups, and straws being used only once before being discarded. Many of these products have a very short lifespan, yet they can persist in the environment for hundreds of years.

Once plastic waste enters rivers and oceans, it is difficult, if not impossible, to retrieve. Mechanical systems can be effective at picking up large pieces of plastic from inland waters, but once plastics break down into microplastics (smaller than 5mm in width), they become virtually impossible to recover. Microplastics are spread throughout the water column and have been found in every corner of the globe, from Mount Everest to the Mariana Trench.

The impacts of plastic pollution on human health and the environment are significant. Microplastics have been found in human blood, placentas, and in food and drinks, including tap water, beer, and salt. Several chemicals used in plastic production are known to be carcinogenic and can cause various health disorders. Plastic pollution also affects biodiversity and ecosystems, with nearly 2,100 species, including endangered ones, known to be affected. Wildlife such as birds, whales, fish, and turtles often mistake plastic waste for food, leading to ingestion, suffocation, and entanglement.

To address plastic pollution, a global plastics treaty is needed to reduce plastic production, phase out harmful subsidies, eliminate harmful products and chemicals, and improve waste management systems. Individual actions, such as reducing plastic consumption, reusing and recycling plastic, and properly disposing of chemical cleaners, oils, and non-biodegradable items, can also make a difference.

Oil pollution

Sources of Oil Pollution

• Oil spills from large tankers, drill platforms, barges, and ships
• Pipeline ruptures or well blowouts on land
• Offshore drilling operations and accidental spills
• Natural seepage from the ocean floor and eroding sedimentary rocks
• Industrial and domestic runoff, including storm drains and pavement runoff
• Bilge pumping and other ship operations
• Landfill leaks and leachates from unlined municipal refuse
• Accidental or intentional discharge from vehicles, lawnmowers, and fuel depots

Impacts of Oil Pollution

• Ecosystems: Oil spills can contaminate beaches, sediment, plants, and animals. Oil-coated birds and marine animals lose their ability to insulate themselves, and ingestion of oil during cleaning can be harmful. Oil spills can suffocate fish and block light from reaching photosynthetic plants. It can also disrupt the reproductive cycles of fish and other aquatic life, leading to liver disease and growth problems.
• Water Sources: Oil pollution affects both marine and freshwater sources, including rivers, reservoirs, lakes, and seas. It can contaminate drinking water, posing risks to human health and safety.
• Communities: Oil pollution can severely impact fishing and hunting activities, particularly in rural communities that rely on these sources for sustenance and income. It can also lead to closed beaches and harbours, disrupting recreational activities and local economies.

Cleaning Up Oil Spills

The methods for cleaning up oil spills depend on the type and amount of oil, location, and weather conditions:

• Containment and Booms: The primary step is to contain the spill using booms, which are floating barriers that prevent the oil from spreading. Different types of booms, such as hard booms, sorbent booms, and fire booms, are used depending on the situation.
• Skimmers and Sorbents: Skimmer boats can remove oil from the water surface without altering its physical or chemical properties. Sorbent materials, both natural and synthetic, are used to absorb and remove oil from the water.
• Burning: In some cases, oil is burned off the water surface, but this can release additional pollutants and cause atmospheric pollution.
• Chemical Dispersants: Chemicals can be applied to the surface to speed up the natural process of oil breakdown, but their long-term effects are unknown.
• Bioremediation: Natural microorganisms can break down oil, and this process can be enhanced by adding nutrients.

Reducing Oil Pollution

To reduce oil pollution, it is crucial to properly dispose of oil, paint, and hazardous chemicals. The United Nations treaty, MARPOL, has implemented regulations for tankers and ships to use oil-pollution prevention equipment and enforce oil spill response plans. Individual countries have also passed legislation, such as the Oil Pollution Act, to strengthen regulations and assign liability for cleanup and damage costs.

Radioactive waste

Treatment of Radioactive Wastewater

The treatment of radioactive wastewater aims to eliminate its threats to the environment and human health. Here are some commonly used treatment technologies:

• Ion Exchange: This method uses ion exchangers to separate and extract specific ions from the wastewater. It is suitable for treating waste liquids with low salt content.
• Chemical Precipitation: This technique co-precipitates the precipitant and radionuclides in the waste liquid, reducing its specific activity. It is simple, cost-effective, and widely applicable but may have challenges with solid-liquid separation and treating anionic radionuclides.
• Evaporative Concentration: This method evaporates water from the waste liquid, leaving behind the non-volatile radionuclides for further solidification and isolation. It has a high decontamination coefficient and volume reduction capability but may have issues with energy consumption and equipment corrosion.
• Membrane Separation: Membrane technology uses selective separation membranes to achieve purification, concentration, and other goals. It offers advantages such as energy efficiency and flexibility but requires high-quality raw water and is prone to membrane fouling.
• Adsorption: This method uses porous adsorbent materials to remove radionuclides from the waste liquid. Different types of adsorbents, such as inorganic adsorbents (zeolite, activated carbon), biomass adsorbents, and synthetic polymer materials, can be selected based on the nature of the waste liquid.
• Biotechnology: This approach uses plants or microbial cells to remove radionuclides through biotransformation, biosorption, bioaccumulation, sedimentation, and solubilization mechanisms. It is environmentally friendly, efficient, and cost-effective but has limitations due to the radiation tolerance of microbes.
• Photocatalysis: This technique converts solar energy into chemical energy in the presence of a photocatalyst, allowing for the reduction of radionuclides. It offers a promising approach for treating organic wastewater but has limitations in terms of charge separation efficiency and sunlight utilization.

Environmental and Human Impacts

The release of radioactive wastewater into bodies of water can have both environmental and human health impacts. Radioactive contaminants can enter the food chain, raising consumer concerns, especially in fisheries. Exposure to radioactive elements can increase the risk of cancer and other health issues. The effects on marine life and humans depend on the type and concentration of radionuclides released. While dilution can help reduce the concentration of radionuclides, the potential for bioaccumulation and exposure pathways, such as organically bound tritium (OBT), should also be considered.

Future Directions

The management of radioactive wastewater is a critical aspect of nuclear technology utilisation. The combination of multiple treatment processes, such as ion exchange, membrane separation, and adsorption, can help improve the effectiveness of radioactive wastewater treatment. Additionally, the development of new membrane materials and anti-fouling membranes is essential to enhance the efficiency of membrane technology.

Furthermore, there is a need for internationally accepted regulations for radiation exposure levels across different species to ensure that only safe levels of nuclear waste are released into the ocean. As nuclear power continues to play a role in tackling climate change, transparency and advancements in nuclear security and waste management are crucial to building public confidence in nuclear energy.

Fracking

The potential for water pollution from fracking is not limited to groundwater but also extends to surface water. Spills and leaks of fracking fluids, inadequate well construction, and poor wastewater management practices have all been identified as contributing factors to water pollution. The chemicals used in fracking fluids are often not fully disclosed, making it challenging to assess the full impact of spills and leaks on water bodies.

The impact of fracking on water pollution has led to calls for stricter regulations and re-evaluation of existing drinking water policies. The health and environmental risks associated with fracking underscore the need for comprehensive oversight and regulation of the industry to mitigate potential harm to communities and the environment.

Frequently asked questions