Source fate transport Flashcards
Differentiate between the sources of hazardous waste generated by industrial facilities and households.
- Industrial facilities generate hazardous waste such as chemical byproducts, solvents, and toxic hydrocarbons during manufacturing processes (e.g., chemical and petrochemical industries).
- Households contribute to hazardous waste via items like old paint cans, cleaning supplies, and electronic waste, which may contain heavy metals or toxic chemicals.
How do healthcare facilities contribute to hazardous and toxic waste generation?
Healthcare facilities generate hazardous waste, including pharmaceutical waste, used sharps (e.g., needles), and biohazardous materials like blood or used PPE. Improper disposal of these can lead to environmental contamination.
Compare the factors affecting the transport of hazardous waste in air and water.
- Air: Wind speed and direction, particle size, and gravity influence air transport. For example, smaller particles can remain suspended longer and travel greater distances.
- Water: Transport depends on water currents, solubility, and sedimentation. Highly soluble pollutants may travel far, while less soluble ones may attach to sediments and settle.
What is the role of biota in the transport of hazardous waste?
Biota transport involves bioaccumulation and biomagnification. Contaminants, such as heavy metals or organic pollutants, are absorbed by lower organisms and concentrate in higher trophic levels, affecting top predators and humans.
What are the implications of soil permeability on pollutant transport?
Soils with higher permeability (e.g., sandy soils) allow faster transport of contaminants, increasing the risk of groundwater contamination. Clayey soils, being less permeable, slow the movement but may lead to surface accumulation.
What distinguishes persistence from biodegradation in the environmental fate of hazardous substances?
- Persistence refers to the prolonged presence of substances in the environment without degradation, such as persistent organic pollutants (POPs).
- Biodegradation involves breaking down contaminants into less harmful substances through biological processes, reducing environmental and health risks.
How does volatilization impact the fate of hazardous substances?
Volatilization causes certain hazardous substances to enter the air as gases. This increases their potential for long-range transport and contributes to air pollution, affecting areas far from the source.
What are the key environmental impacts of hazardous waste on ecosystems?
- Soil contamination: Reduces soil health and fertility due to the presence of heavy metals or pesticides.
- Water contamination: Leads to issues such as oxygen depletion in aquatic systems and bioaccumulation of pollutants in aquatic organisms.
How do hazardous substances affect human health through exposure pathways?
Exposure occurs through ingestion (contaminated food/water), inhalation (airborne pollutants), or dermal contact. Chronic exposure to substances like heavy metals can lead to cancer, neurological issues, or reproductive problems.
Why is the legacy contamination of hazardous substances a significant concern?
Legacy contamination persists for decades, affecting ecosystems and human health long after the initial release. Persistent substances, such as PCBs, remain in the environment and bioaccumulate over time.
How does the construction industry contribute to hazardous waste, and what materials are most concerning?
The construction industry produces hazardous waste such as asbestos and lead-based paint, which can become harmful during demolition or improper handling.
In what ways do agricultural practices contribute to hazardous waste generation?
Agriculture generates hazardous waste through pesticides, herbicides, and fertilizers. These can contaminate soil and water if not properly managed.
What are the challenges associated with waste management facilities themselves becoming sources of hazardous waste?
Waste management facilities may release hazardous leachate from landfills or ash from incineration processes, leading to soil and groundwater contamination.
Explain how long-range air transport can spread hazardous pollutants across regions.
Wind currents can carry airborne pollutants, like volatile organic compounds (VOCs) or fine particulates, across regions or continents, contaminating remote ecosystems.
How does soil permeability influence the depth at which contaminants may reach groundwater?
High-permeability soils, like sand, facilitate faster downward movement of contaminants, increasing the likelihood of groundwater pollution. Low-permeability soils, like clay, slow this process.
