Hazardous Waste

Chapter 1: Introduction to Hazardous Waste

  • Definition of Hazardous Waste:

    • Any waste that poses danger to humans, plants, or animals.

    • Must be handled and disposed of with caution.

  • Terminology:

    • In Malaysia, "hazardous waste" is often referred to as "shadow waste".

  • Regulatory Framework:

    • The management of hazardous waste is governed by the Environmental Quality (Scheduled Waste) Regulation 2005.

  • Lecture Focus Areas:

    • Overview of the regulation covering:

      • List of hazardous materials (shadow waste).

      • Responsibilities of waste generators.

      • Notifications to the Department of Environment (DOE).

      • Treatment, recovery, storage, transportation, disposal, and spill management of shadow waste.

Classification of Scheduled Waste

  • Coding System:

    • Chemicals categorized into 5 major groups (SW1 to SW5).

    • Details found in the 1st Schedule of the regulation.

  • Group SW1 (Metal Bearing Waste):

    • Example: SW101 - Arsenic compounds; SW102 - Lead acid batteries.

  • Group SW2 (Inorganic Waste):

    • Example: SW202 - Waste catalysts; SW204 - Sludges with metals (e.g., chromium, copper).

  • Group SW3 (Organic Waste):

    • Example: SW316 - Acid sludges; SW321 - Rubber waste with organic solvents.

  • Group SW4 (Inorganic/Organic Waste):

    • Example: SW401 - Spent catalysts containing heavy metals.

  • Group SW5 (Other Waste):

    • Example: SW501 - Residues from shadow waste treatment/recovery.

Identifying and Classifying Shadow Waste

  • Identification Steps:

    1. Determine if raw materials or additives are listed in the 1st schedule.

    2. Use Material Safety Data Sheets (MSDS) for reference.

  • Sample Analysis:

    • Conduct Toxicity Characteristic Leaching Procedure (TCLP) to assess hazardous characteristics.

  • Notification Requirement:

    • Waste generators must notify DOE within 30 days of generating scheduled waste using the appropriate form from the regulation's 2nd schedule.

Storage and Labeling of Shadow Waste

  • Storage Guidelines:

    • Use containers that are compatible and durable to prevent leaks.

    • Segregate waste based on its category code.

    • Incompatible waste must be stored separately.

    • Containers should be closed when not in use.

  • Storage Limits:

    • Shredded waste must not be stored longer than 180 days or exceed 20 metric tonnes without consent from DOE.

  • Labeling Requirements:

    • All containers must be labeled with respective hazardous waste signage.

Chapter 2: Alkaline Liquid Waste

  • Container Selection:

    • Choose containers based on waste characteristics to avoid reactions.

    • Examples:

      • Bunghole drums: Steel or plastic for organic/inorganic liquid waste.

      • Steel drums not suitable for acids or alkalis.

      • Intermediate Bulk Containers (IBC): Versatile for various wastes, including oils and solvents.

  • Labeling Compliance:

    • Adhere to safety signage and ensure proper labeling based on the waste type.

  • Incompatibility Guidelines:

    • Alkaline waste (Group 1A) should not be stored with acidic waste (Group 1B).

    • Specific Groupings:

      • Group 2A: Asbestos/pesticides incompatible with solvents (Group 2B).

  • Disposal Regulations:

    • Waste must be treated at prescribed premises licensed by DOE.

    • Maintain an inventory of treated or disposed waste for 3 years.

    • Prepare a consignment note and submit to DOE when transporting shadow waste.

Chapter 3: Shaded Waste Regulation

  • Inventory Management:

    • Maintain a detailed inventory of chemicals and check compatibility.

  • Understanding Regulations:

    • Knowledge of Scheduled Waste Regulation 2005 is critical for compliance.

  • Treatment Methods:

    • Physical Treatments:

      • Remove and separate hazardous waste (evaporators, gravity settling, and flotation).

    • Chemical Treatments:

      • Modify waste’s chemical properties for safety via neutralization and precipitation.

    • Bioremediation:

      • Utilize living organisms (bacteria) for degrading hazardous materials.

Chapter 4: The Organic Waste

  • Neutralization Procedures:

    • Use lime/sodium hydroxide for acids and sulfuric/hydrochloric acid for alkalis; testing is essential.

  • Precipitation Process:

    • Involves the reduction of soluble substances for easier handling.

  • Bioremediation Techniques:

    • Methods include land farming and windrow composting for microbial degradation.

    • Biopiling to aerate contaminated sediments and enhance degradation.

Chapter 5: Conclusion

  • Secured Landfill Overview:

    • Unlike sanitary landfills, secured landfills contain waste in containers and undergo solidification/stabilization processes using materials like cement.

  • Underground Injection:

    • Involves pumping liquid waste into deep porous rock formations.

  • Incineration:

    • Minimizes waste volume; however, residual ash may still be hazardous and requires careful monitoring.

  • Innovative Disposal Concepts:

    • Exploration of waste-to-energy methods for hazardous waste management.