3 Water Chem-Pollutants (1)

Cohesion and Adhesion

• Cohesion: The attraction between molecules of the same substance, causing them to stick together. This property is vital for processes such as the formation of droplets and the rise of water in plants via capillary action.

• Adhesion: The attraction between molecules of different substances, allowing them to bond together. This property is important in helping water adhere to surfaces, which facilitates processes like water moving through soil and along the sides of plant cells.

The Water Molecule

• Water (H2O) molecule consists of two hydrogen atoms covalently bonded to one oxygen atom. The polar nature of water molecules leads to hydrogen bonding, which contributes to its unique properties, such as high surface tension and specific heat capacity.

Water on Earth

• Distribution of Water:

  • 97% of Earth's water is salt water (oceans), primarily unsuitable for human consumption.

  • 2% is found in polar ice caps, which are crucial for regulating the Earth’s temperature and sea levels.

  • Only 1% is available as fresh water for human use, making freshwater conservation vital.

Fresh Water Distribution

• Total Fresh Water (3%):

  • Ground water: 30.1%, crucial for drinking water and agriculture.

  • Ice caps and glaciers: 68.7%, serve as a long-term freshwater reserve.

  • Surface water: 3%, which includes:

    • Swamps: 11%, important for biodiversity and water filtration.

    • Lakes: 87% of surface water, a substantial resource for ecosystems and human usage.

    • Rivers: 2%, vital for transportation, irrigation, and energy production.

Interesting Facts About Water

• Ice is the second most common form of water on Earth, stable in various ecosystems.

• If all ice melted, sea levels would rise by approximately 70 meters, dramatically affecting coastal regions and ecosystems.

• If all melted ice fell as rain simultaneously, the entire planet would receive about 1 inch of rain, illustrating the substantial amount of water contained in ice caps.

Salinity of Ocean Water

• Average ocean water contains about 1 cup of salt per gallon, varying by location due to factors such as evaporation and freshwater influx.

• The Atlantic Ocean is saltier than the Pacific Ocean because of higher evaporation rates and less inflow of freshwater.

• Don Juan Pond in Antarctica is the saltiest water body on Earth, showcasing extreme conditions that can support certain microbial life.

• High salinity leads to a significant freezing-point depression, allowing liquid presence at extremely low temperatures (−50 °C), enabling the survival of specific organisms in harsh environments.

Water and Comets

• Earth's original water likely originated from rocky materials left behind during planetary formation, but comets, mainly composed of water ice, may have contributed significantly over geological time scales, altering theories about the origin of Earth’s water supply.

Human Dependence on Water

• Newborns have approximately 78% water content, which decreases to about 55-60% in adults.

• Water's critical roles:

  • Nutrient transport in blood, essential for cellular function and metabolism.

  • Waste removal from the body, playing a crucial role in kidney function and overall health.

  • Temperature regulation, where the high specific heat of water helps maintain stable body temperature during metabolic processes.

  • Cushioning for organs, protecting vital organs during physical impacts and reducing the risk of injury.

Global Water Issues

• Sewage Pollution: 2 million tons of sewage and pollution enter waterways daily, highlighting the need for improved sanitation and waste management strategies worldwide.

• Unsafe water results in more deaths each year than all forms of violence combined, primarily due to waterborne diseases such as cholera and dysentery.

Philippine Waters

• The Philippines has abundant water resources but low freshwater availability per capita, leading to significant water-related issues.

• Causes of water shortage in the Philippines include:

  • Poor water management practices, leading to inefficient water use and wastage.

  • Urbanization leading to increased household demand, outpacing available resources.

• Despite rich biodiversity, the country has faced water stress since 2017, indicating a need for sustainable water practices and policies.

Sustainable Development Goals (SDG) 6

• Global warming is projected to worsen the water cycle, increasing both droughts and flooding, thereby impacting water availability and quality around the world.

Countries with High Water Waste (2023)

• United States: 444.29 billion m³ of water wasted annually.

• Indonesia: 222.64 billion m³.

• Pakistan: 183.45 billion m³.

• Iran: 93.3 billion m³.

• Mexico: 89.55 billion m³.

• Philippines: 85.87 billion m³.

• These statistics highlight regions facing severe water stress and necessitate intervention.

Israel and Water Conservation

• Israel leads in water conservation initiatives, recycling 85% of wastewater, significantly contributing to sustainable development in arid regions.

• Plans for 50% of farming needs to use recycled water, showcasing innovative approaches to efficient water use.

Water Pollution

• Defined as contamination of water bodies from harmful substances, degrading quality and posing risks to health. Effective monitoring and remediation strategies are essential to combat this.

Sources of Water Pollution

• Waste from:

  • Residential buildings (sewage and household chemicals).

  • Factories (industrial runoff and chemical waste).

  • Agriculture (fertilizers, pesticides, and animal waste).

• Main Pollutants Include: Bacteria, viruses, parasites, fertilizers, toxic chemicals, plastics, and radioactive substances, all of which can have severe impacts on aquatic ecosystems and human health.

Thermal Pollution

• Caused by industrial release of heated water into natural water bodies, which can endanger aquatic life by lowering oxygen levels and disturbing ecosystems.

Major Causes of Water Pollution

• With water being a universal solvent, it readily dissolves various pollutants, making it vital to manage land use and chemical application carefully.

• Agricultural runoff is a significant contributor, introducing fertilizers and pathogens into waterways, necessitating practices like integrated pest management and reduced fertilizer use.

Addressing Agricultural Pollution

• Over 80% of water degradation is linked to agricultural practices, demanding urgent reforms in farming techniques, including nutrient management and sustainable land use practices.

Wastewater Management

• Wastewater from various sources, including domestic and industrial activities, poses significant pollution challenges worldwide.

• Processes of wastewater management include:

  • Collection: Wastewater is gathered from various sources via a network of pipes, ensuring it reaches treatment facilities efficiently.

  • Preliminary Treatment: This initial phase involves screening (to remove large solids) and grit removal (to eliminate sand and gravel) to protect subsequent treatment processes.

  • Primary Treatment: Involves sedimentation where solids settle to the bottom, forming sludge while lighter materials float to the surface, creating scum.

  • Secondary Treatment: Biological treatment processes (such as activated sludge systems, trickling filters, or other biological treatment processes) degrade organic matter using microorganisms.

  • Tertiary Treatment: Advanced treatment methods (including filtration, chemical disinfection using chlorine, UV light, or ozone) remove remaining contaminants, disinfecting the water before release or reuse.

  • Disposal/Reuse: Treated wastewater can be released into the environment or reused for irrigation, industrial processes, or aquifer recharge, emphasizing water recycling practices.

• Greater than 80% of the world’s wastewater returns untreated into the environment, stressing the need for improved wastewater management systems.

Oil Pollution

• Accounts for significant ocean contamination, with regular operational activities in oil drilling and transportation contributing more than tanker spills.

Radioactive Waste

• Emitted during uranium mining, nuclear power generation, and military applications, posing long-term environmental hazards that require stringent management protocols.

Public Health and Access to Water

• Safe, readily available water is crucial for health and nutrient transport, impacting quality of life and economic stability.

• Sustainable Development Goal 6.1 aims to ensure universal access to safe drinking water as a fundamental human right.