Understanding Environmental Pollution and Remediation
Environmental Pollution: Causes, Effects, and Solutions
Air Pollution
Air pollution occurs when a change in the composition of air alters its physical or chemical properties, causing measurable harmful effects on humans, animals, vegetation, or materials.
Atmospheric Environmental Problems
- The Greenhouse Effect: This phenomenon is related to the increase of certain gases in the atmosphere, mainly carbon dioxide from burning fossil fuels. These gases increase the barrier to infrared radiation emitted by the Earth, preventing it from escaping into outer space.
- The Destruction of the Ozone Layer: Ozone gas in the stratosphere acts as a filter for ultraviolet radiation. However, there are holes in this layer, which are essentially windows through which harmful ultraviolet rays can pass.
- Acid Rain: Acid rain contains acids caused by chemical reactions between nitrogen oxides, sulfur emissions, and water vapor in clouds.
- Pollution in Urban Areas: The urban atmosphere contains solid and gaseous waste. This results in increased levels of suspended solids and particles, leading to fog formation. Acid smog is typical of winter conditions with high humidity, while photochemical smog coincides with high temperatures and low humidity.
Natural Self-Purification Techniques
- Fixation of contaminants on the surface of suspended solid particles, which then settle to the bottom.
- Aeration to remove contaminating organic compounds that can be destroyed by a chemical reaction with oxygen dissolved in water.
Water Pollution
- The presence of harmful microorganisms in wastewater, mainly in urban waste.
- Agricultural fertilizer runoff into rivers, discharges of detergents and cleaning agents into the sewer system in urban areas, and wastewater discharge containing metals such as mercury and lead from industrial activities.
- Thermal Pollution of Water: Temperature is a limiting factor for aquatic life. Changes in the thermal regime of water have negative ecological impacts, primarily through the discharge of warm or hot water from cooling circuits of industrial facilities into rivers and reservoirs.
- Marine Pollution by Oil: Accidental oil spills cause oil slicks that are difficult to combat and cause damage to the coast, flora, and fauna.
Soil Pollution
Soil pollution is based on biological activity that enables the partial or total decomposition of organic matter. It also involves the filtration capacity to retain solid contaminants and the activity of soluble chemical substances involved in chemical reactions that destroy contaminants.
Main Soil Contaminants
- Soluble Substances: Remnants of fertilizers and pesticides, metal compounds, and discharges from mining and chemical industries.
- Organic Pollutants: Remnants of solid or liquid hydrocarbons from oil spills, which cause “tar.”
- Salinization: The process by which soluble salts from saline groundwater near the surface crystallize and accumulate on the ground.
Techniques for Soil Remediation
- Injecting water into the ground through a system of galleries over contaminated land with a slope to collect the effluent loaded with contaminants.
- Applying a chemical treatment that results in soil reactions leading to the destruction of the contaminant.
- Executing a biological treatment, favoring microbiological processes that involve the degradation of pollutants.
Waste Disposal
- Landfill: Secure, controlled landfills.
- Incineration: Burning of waste.
- Solidification: Solidifying waste materials.