Module 4: Waste Disposal and Recycling Methods

4.1 Landfill Disposal (Sanitary vs. Open Dumps)

Landfills remain a common disposal method for non-hazardous waste, but their design and operation significantly impact environmental safety.

Sanitary Landfills

• Engineered Containment:

• Clay/plastic liners prevent leachate from contaminating groundwater.

• Leachate collection systems and methane gas recovery for energy.

• Operational Standards:

• Daily soil cover to reduce odor, pests, and windblown debris.

• Compacted waste layers to maximize space efficiency.

• Regulatory Compliance:

• Must meet EPA Subtitle D (U.S.) or EU Landfill Directive requirements.

• Groundwater monitoring for 30+ years post-closure.

Open Dumps (Unregulated)

• Environmental Risks:

• No liners or leachate control → soil/water pollution.

• Methane emissions contribute to climate change.

• Disease vectors (rodents, insects).

• Global Concerns:

• Common in developing nations; banned in most developed countries.

• Illegal dumping fines can exceed $50,000 (U.S.).

Best Practice: Prioritize recycling and diversion to reduce landfill reliance.

4.2 Recycling and Recovery of Non-Hazardous Waste

Recycling converts waste into reusable materials, conserving resources and reducing landfill demand.

Common Recyclables & Processes:

Challenges & Solutions:

• Contamination: Food residue in recyclables → strict sorting required.

• Market Fluctuations: China’s 2018 "National Sword" policy reduced global recycling demand → invest in local processing.

• Single-Stream vs. Dual-Stream:

• Single-stream (mixed recycling) increases participation but lowers purity.

• Dual-stream (pre-sorted) yields higher-quality materials.

Best Practice: Partner with certified recycling facilities (e.g., MRFs) for audits.

4.3 Composting and Organic Waste Management

Composting decomposes organic waste (food scraps, yard trimmings) into nutrient-rich soil amendments.

Methods & Applications:

• Aerobic Composting:

• Requires oxygen, moisture, and turning → produces heat (kills pathogens).

• Used for municipal/industrial food waste (e.g., 2–6 month process).

• Anaerobic Digestion:

• Oxygen-free tanks generate biogas (methane for energy).

• Common in wastewater treatment plants.

• Vermicomposting:

• Worms break down waste → fast, small-scale (e.g., restaurants, homes).

Regulatory Considerations:

• EU Circular Economy Package: Mandates organic waste separation by 2024.

• U.S. State Laws: California’s SB 1383 requires businesses to compost.

Best Practice: Educate households/businesses on "green bin" programs.

4.4 Incineration and Energy Recovery (Where Applicable)

Waste-to-Energy (WTE) plants burn non-recyclable waste to generate electricity/heat.

Modern Incineration Standards:

• Emissions Control:

• Scrubbers remove dioxins, NOx, and particulate matter.

• EU’s Industrial Emissions Directive (IED) sets strict limits.

• Energy Output:

• 1 ton of waste = 500–700 kWh of electricity (powers ~500 homes/day).

• District heating systems (e.g., Sweden recovers 99% of waste energy).

Limitations & Alternatives:

• High Costs: $150–$200 million plant construction.

• Public Opposition: "Not in My Backyard" (NIMBY) protests over air quality.

• Better for: Non-recyclable plastics, treated wood, medical waste.

Best Practice: Use incineration only after maximizing recycling/composting.

Next Steps: Module 5 covers Environmental and Health Considerations, including pollution prevention and occupational safety.