Water's Journey: Store Pollution And Prevention

Water pollution is a pressing issue that poses a threat to human health, the environment, and the economy. It occurs when harmful substances contaminate water bodies, degrading water quality and rendering it toxic. With only 3% of freshwater available for human consumption, it is crucial to address the sources of water pollution and implement effective solutions. The major sources of water pollution include agricultural runoff, urban stormwater runoff, industrial discharges, plastic litter, and household waste. These sources release toxic chemicals, microorganisms, and waste into water systems, endangering aquatic life and human health. To combat water pollution, individuals can properly dispose of waste, reduce plastic consumption, and minimize the use of harmful chemicals. Additionally, promoting sustainable agriculture and implementing green infrastructure are essential steps toward reducing water pollution and ensuring access to clean drinking water.

Sewage and wastewater

According to the United Nations, more than 80% of the world's wastewater is released back into the environment without proper treatment. This untreated wastewater contains harmful chemicals, bacteria, and pathogens that breed diseases and cause health issues in humans and animals. It also introduces a cocktail of contaminants such as pharmaceuticals, microplastics, heavy metals, and endocrine disruptors, which threaten food and water security and harm marine life.

Inadequate wastewater treatment can lead to habitat loss, extinction, and the collapse of fisheries. It also contributes to eutrophication, where excessive nutrients cause dense plant growth and deplete oxygen levels, leading to the death of aquatic animals.

To address wastewater pollution, it is essential to implement treatment options that protect carbon-storing ecosystems and invest in innovative practices that divert waste into valuable resources. Additionally, public awareness and education are crucial in reducing the stigma around wastewater and inspiring action to protect aquatic ecosystems.

Oil leaks and spills

Oil spills are a significant contributor to water pollution. Oil spills can occur due to human error, natural disasters, technical failures, or deliberate releases, with human error and equipment failure being the most common causes. Oil spills have severe environmental, economic, and social consequences. They can harm marine wildlife, such as fish, birds, and sea otters, and can also contaminate drinking water supplies.

Oil spills at sea are particularly damaging because the oil can spread for hundreds of nautical miles, coating beaches, seabirds, mammals, shellfish, and other organisms in its path. Oil spills on land are more containable, as makeshift earth dams can be built to prevent the oil from escaping, and animals can more easily avoid the spilled oil.

The impact of oil spills on marine life is twofold:

• Fouling or oiling: Oil can coat a bird's wings, leaving it unable to fly, or strip away the insulating properties of a sea otter's fur, making it vulnerable to hypothermia. The degree of oiling often determines the affected animal's chances of survival.
• Oil toxicity: Oil contains various toxic compounds that can cause heart damage, stunted growth, immune system issues, and even death. The 2010 Deepwater Horizon oil spill led to an expanded understanding of oil toxicity.

Cleanup and recovery from an oil spill are challenging and depend on factors such as the type of oil spilled, water temperature, and the presence of shorelines and beaches. Physical cleanups can be expensive, and chemical remediation is often used instead. Bioremediation, which uses microorganisms or biological agents to break down or remove oil, is also an option.

To prevent oil spills, double hulls have been built into vessels, reducing the risk and severity of spills in the event of a collision or grounding. Additionally, innovations like GPS, sectioning of vessels, and sea lanes in narrow straits have contributed to a decrease in oil tanker spills.

Industrial waste

The production of industrial goods generates wastewater contaminated with toxic substances. This wastewater is often discharged untreated into nearby public waters, polluting lakes, rivers, and coastal waters. In fact, about 20% of freshwater withdrawn worldwide is used by industries and subsequently polluted. While some of this water is properly cleaned by wastewater recycling systems and reused or disposed of in an environmentally friendly manner, this is not always the case.

Some of the common industrial activities that cause pollution include:

• Burning coal and fossil fuels (oil, petroleum, and natural gas)
• Releasing chemical solvents
• Radioactive material leakage
• Releasing untreated waste

The waste generated during industrial processes can be both hazardous and non-hazardous. Hazardous waste includes substances such as ammonia, solvents, and petroleum, which are dangerous because they are difficult to biodegrade and can accumulate in water sediments. Non-hazardous waste, such as rubbish and debris, can also be harmful to the environment.

The consequences of industrial water pollution are severe. It leads to eutrophication, where an overabundance of toxic algae and plants increase carbon dioxide levels in the water, reducing sunlight and causing hypoxia (lack of oxygen), which is deadly for aquatic life. It also affects the soil and air, creating an unhealthy environment for humans, animals, and plants.

To reduce industrial water pollution, several measures can be implemented:

• Policy changes and effective enforcement
• Controlled industrial growth and forward planning
• Investment in new, sustainable technologies
• Improved waste disposal and treatment
• Reduced usage of natural resources that involve damaging extraction
• Adoption of water recycling and preservation practices
• Implementation of advanced water treatment technologies

Marine dumping

The deliberate disposal of waste into the ocean is now governed by international policies and regulations. The 1972 London Convention, which the United States ratified in 1975, is one of the first international agreements for the protection of the marine environment from human activities. It establishes global rules and standards for preventing, reducing, and controlling marine pollution by dumping. The 1996 London Protocol, a freestanding treaty that entered into force in 2006, implements a precautionary approach that prohibits all dumping except for wastes or other matters described in Annex 1 of the Protocol.

In the United States, the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972 regulates the transportation and disposition of materials in the ocean that would adversely affect human health, welfare, or amenities, or the marine environment, ecological systems, or economic potentialities. The MPRSA has been instrumental in preventing harmful materials from entering the oceans and will continue to protect ocean and coastal resources in the future.

Despite these regulations, marine dumping continues to be a significant issue. Dredged material, industrial waste, sewage sludge, and radioactive waste are among the most toxic materials dumped into the ocean. Dredging contributes about 80% of all waste dumped into the ocean, with several million tons of material dumped each year. Rivers, canals, and harbors are dredged to remove silt and sand buildup or to create new waterways. While most of the dredged material is dumped in the ocean, some of it ends up in landfills or is used for development.

The impacts of marine dumping are far-reaching and detrimental. It can destroy or degrade important habitats for aquatic species, cause coastal erosion, and lead to coastal salutation, affecting the health and productivity of the marine environment. Marine debris, such as plastic bags, balloons, and containers, can be mistaken for food by marine animals, leading to ingestion or entanglement. This has severe consequences for species like sea turtles, whales, dolphins, seabirds, and seals. Marine debris can also damage boat engines and propellers.

In addition to the direct impacts on marine life, marine dumping has indirect effects on the marine environment. For example, nutrient pollution from fertilizers, pesticides, and oil can cause algal blooms, which can clog waterways and lead to the death of seagrass, kelp beds, and entire ecosystems. These dead zones can be as large as entire states and are found in coastal zones, bays, and estuaries. Marine dumping also contributes to the presence of pollutants like mercury, PCBs, and pesticides in seafood, posing risks of birth defects, cancer, and neurological problems, especially in infants.

While there have been efforts to address marine dumping, such as the Ship to Shore Trash Campaign, where fishermen bring their garbage ashore instead of tossing it overboard, more widespread action is needed to curb this practice and mitigate its detrimental effects on the marine environment and human health.

Radioactive waste

There are several treatment technologies for radioactive wastewater:

• Ion exchange: This technology uses ions on an ion exchanger to separate and extract certain specific ions from the wastewater. It is usually suitable for treating waste liquids with low salt content.
• Chemical precipitation: This technology reduces the specific activity of radioactive wastewater by co-precipitating the precipitant and the radionuclides in the waste liquid. It has the advantages of a simple process, low cost, and a wide application range.
• Evaporative concentration: This method is commonly used to concentrate radioactive waste liquid. The basic working principle is to send the radioactive waste liquid into an evaporator and heat it with an electric heater or introduce heating steam. The water in the waste liquid is heated to form water vapour, which is then cooled to form condensed water. After passing the test, it is discharged or reused, while the non-volatile radionuclides remain in the water and are then discharged and undergo subsequent solidification treatment.
• Membrane separation: Membranes are functional materials with selective separation capabilities. They can be used to separate, purify, concentrate, etc. Due to their advantages of saving energy, environmental protection, high efficiency, economy, and easy control, they are widely used in sewage treatment.
• Adsorption: This technology uses porous adsorbent materials to remove radionuclides from the waste liquid. Different types of adsorbents can be selected depending on the nature of the waste liquid.
• Biotechnology: This technology uses plants or microbial cells as media to remove radionuclides through biotransformation, biosorption, bioaccumulation, sedimentation, and solubilization mechanisms. It has the advantages of being environmentally friendly, highly efficient, mild, low cost, low energy consumption, and producing no secondary pollution.
• Photocatalysis: This technology converts solar energy into chemical energy in the presence of a photocatalyst. The photocatalyst can chemically change the reactant after absorbing light, and the excited photocatalyst can interact with the reactant multiple times.

The combination of multiple treatment processes can develop their advantages and compensate for their shortcomings. For example, the activity and recovery rate of the 90Sr purified fraction have been improved by combining ion exchange chromatography, extraction chromatography, and precipitation. However, the combined process has high design requirements and operating costs, restricting its application and operation.

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