Waste Management Principles and Environmental Mitigation
Definition and Principles of Waste
Waste is defined as any substance or object that its owner discards or is obliged to discard. It also refers to materials generated in production and consumption that have not reached an economic value.
Core Waste Management Strategies
- Prevent waste generation.
- Transform waste into resources by applying a circular economy.
- Reduce environmental impact and global warming.
- Promote best available technologies and define criteria for infrastructure.
Physical, Chemical, and Biological Properties
Waste characterization is essential for effective management:
- Physical Properties: Includes density (important for sizing transport equipment and landfill capacity), humidity (determined by drying samples at 105 °C), and particle size (analyzed using sieves or magnetic separators).
- Chemical Properties: Evaluated by testing combustible volatile matter, fixed carbon, and ash (via ignition at 950 °C). Elemental analysis measures Carbon, Hydrogen, Oxygen, Nitrogen, and Sulfur. Calorific power is also a key factor, measuring heat released during combustion, which is crucial for energy recovery.
- Biological Properties: Relates to the biodegradability of organic fractions and the generation of odors from anaerobic decomposition (e.g., H2S). Degradation times vary: a metro ticket takes 3 to 4 months, chewing gum 5 years, and a plastic bottle more than 100 years.
Waste Categories
Industrial Waste
Treated similarly to urban waste. Includes inert waste (rubber, slag) sent to specific landfills, and hazardous waste (inks, oils) requiring specialized treatment.
Sanitary Waste
Categorized into 5 groups:
- Similar to urban waste (office supplies).
- Sanitary waste assimilable to urban.
- Special sanitary waste (needles, blood).
- Expired drugs.
- Human anatomical remains.
The 4R Hierarchy
- Reduce: Minimize generation.
- Reuse: Give objects a new use.
- Recycle: Convert waste into a new product.
- Recover: Generate energy from waste that cannot be reduced, reused, or recycled.
Mitigation Measures
- Prevention: Applied before a project starts to prevent negative effects (e.g., changing project location or technology).
- Correction: Applied once a project has started to cancel or mitigate an impact (e.g., using filters to reduce gas emissions).
- Compensatory: Does not fix the original impact, but creates a positive effect that offsets the uncorrectable negative impact (e.g., replanting trees).
Treatment and Disposal Methods
Composting
An aerobic biological transformation using microorganisms. The main goals are to create organic fertilizer, stabilize material, destroy pathogens, and retain maximum nutritional content.
Glass Recycling
Glass does not lose its properties when recycled. Stages include: initial cleaning, color separation, breakage and crushing, screening, melting, and molding.
Incineration
Thermal processing with oxygen reduces waste volume by 85-95% and allows for energy recovery. However, it produces gas emissions (NOx, SO2, CO), ash, and metals.
Landfills
These can be controlled landfills (waste placed in regular layers and covered with earth) or clandestine dumps (spontaneous and illegal).
Nuclear Waste
Contaminated with radioactive nuclides with no further use. Management focuses on immobilization and conditioning for temporary and final storage.
Agricultural and Livestock Waste
Includes manure and slurry, which are highly polluting but can be used for biogas and compost. Forest residues (wood) are valued for their high calorific value.
Note: The Action is the cause (what the project does) and the Environmental Component is the receiver (what suffers the effect).