Second International Conference on Waste Management and Technology July 18-19, 2007

Transcription

1 Second International Conference on Waste Management and Technology July 18-19, 2007 Hazardous Waste Management, Treatment and Disposal Timothy G. Townsend, PhD, PE Professor Department of Environmental Engineering Sciences University of Florida

2 Hazardous Waste Historical problem of hazardous wastes Regulatory definition of hazardous waste Hazardous waste management system Generators Transporters Treatment and Disposal Future challenges

3 Nebel (1989) Brown (1980)

4

5 Resource Conservation and Recover The RCRA was passed in Provided framework for developing regulations for solid and hazardous waste in the US. Act

6 Defining Hazardous Waste Waste Materials Solid Waste Hazardous Waste

7 Solid waste as defined by RCRA: Garbage, refuse, sludge from a waste treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, Solid, liquid, semisolid, or contained gaseous material From industrial, commercial, mining, and agricultural operations, and from community activities Excluded: Solids in domestic sewage Solids in irrigation return flows Otherwise regulated discharges to water Radioactive waste

8 Examples of Solid Waste Sources Municipal Waste Vegetative Waste Building Debris Treatment Sludges Mining Waste Industrial Waste

9 Hazardous waste Broadly defined as solid wastes that because of their physical and/or chemical characteristics pose a risk to human health and the environment such that they merit special management Two broad categories: Listed hazardous waste Characteristic hazardous waste Some solid wastes are excluded from being hazardous Example: household wastes

10 Listed Waste F - Waste from nonspecific sources Examples: Spent solvent wastes Electroplating wastes K - Waste from specific sources Examples: Wood Preservation Organic Chemical Manufacturing P, U Commercial Chemical Products Wood Preservation Facility

11 Corrosivity Characteristic Hazardous Wastes that are acidic or alkaline and can readily corrode or dissolve flesh, metal, or other materials. Waste

12 Ignitability Characteristic Hazardous Wastes that can readily catch fire and sustain combustion. Ignitability is not supposed to include all wastes that burn. Waste

13 Reactivity Characteristic Hazardous Wastes that readily explode or undergo violent reactions. Waste

14 Toxicity Characteristic Hazardous Waste Determined using the Toxicity Characteristic Leaching Procedure (TCLP). Only leachable concentration of pollutant is analyzed. In summary, a solid waste is leached in an acid solution for 18 hours and the resulting leachate is analyzed. If the concentration of certain pollutants in the leachate exceeds a standard in the rules, it is a TC hazardous waste (unless otherwise exempted).

15 Solid Waste Size Reduce to Less Than 1 cm Leach 100 g for 18 hours at 30 RPM Filter Solids from Leachate Analyze Leachate X mg/l

16 TCLP Concentrations are Compared to RCRA TC List If the concentration of certain pollutants exceed the TC limit, the solid waste is a hazardous waste. Note: There are also several organic compounds on the TC compound list as well. Metal Concentration (mg/l) Arsenic 5.0 Barium Cadmium 1.0 Chromium 5.0 Lead 5.0 Mercury 0.2 Selenium 1.0 Silver 5.0

17 US Hazardous Wastes in 2005 Both 28% Characteristic 56% Listed 16% Characteristic = 21.5 million tons Listed = 6.1 million tons Both = 10.6 million tons Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 D

18 Characteristic-Only Hazardous Wastes in 2005 Ignitable 2.8% Corrosive 14.6% Reactive 0.4% Multiple 46.7% TC Inorgaincs 10.6% Multiple: Waste having more than one characteristics TC Orgaincs 24.9% Characteristic = 21.5 million tons Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 Data)

19 Listed Hazardous Wastes in 2005 Multiple 31% Waste from non specific source 20% Toxic and other characteristics 2% Acutely hazardous - Toxic and Reactive 3% Waste from specific source 44% Listed = 6.1 million tons Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 Data)

20 Hazardous Waste Types Iron and Steel Mills and Ferroalloy Manufacturing 4% Others 18% Waste Treatment and Disposal 5% Resin, Synthetic Rubber and Fibers and Filaments Manufacturing 5% Petroleum and Coal Products Manufacturing 13% Basic Chemical Manufacturing 55% Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 Data)

21 Management of Hazardous Waste RCRA hazardous waste management system is designed to be cradle to the grave. The waste generator must determine if waste is hazardous and that it is managed appropriately. A chain of paperwork called a manifest is used to track the waste from generation to final disposal.

22 Typical Generator Requirements Proper storage and labeling Manifest system Safety plans Reporting Requirements

23 Types of Hazardous Waste Generators Large Quantity Generators (LQGs) > 1000 kg of hazardous waste per month or > 1 kg of acutely hazardous waste per month Small Quantity Generators (SQGs) Facilities that generate > 100 kg but < 1000 kg of hazardous waste per month Conditionally Exempt Small Quantity Generators (CESQGs) < 100 kg of Hazardous waste per month and < 1 kg of acutely hazardous waste per month

24 Hazardous Waste Transportation Transporters must follow strict requirements for transporting hazardous materials. Transporters participate in manifest system. Vehicles must be properly marked. Transporter can not make decisions on where to deliver waste.

25 Treatment and Disposal Hazardous waste must first be treated prior to final disposal Treatment methods Examples Thermal treatment (incineration) Chemical treatment (e.g., solidification and stabilization) Biological treatment Encapsulation Others Final Disposition Examples Landfills Surface impoundments Deep well injection

26 Waste Treatment

27 Thermal Treatment Rotary kiln incinerator Proper air pollution control technologies must be applied for emission to the atmosphere

28 Physical/Chemical Treatment Many different processes are used to solidify or stabilize a hazardous waste prior to disposal in a landfill. Goals: Reduce the mobility of the chemicals through a chemical reaction Reduce the mobility of the chemicals through Physical encapsulation Lead Concentration (mg/l) 10 5 Concentration corresponding to 100% lecahing Example: ph impact on lead mobility Final ph of the Extraction Solution

29

30 Hazardous Waste Landfill

31 Hazardous Waste Liner Requirements Double Liner 2 ft drainage material Designed to maintain less than 1ft head on liner HDPE Geomembrane Geonet HDPE Geomembrane 3 ft compacted soil K <= 10-7 cm/sec

32 Landfill Double Liner Construction

33 Final Disposition of RCRA Hazardous Waste (by Management Method) Other treatments 22% Deepwell or underground injection 49% Energy recovery 4% Landfill/surface impoundment 5% Disposal 8% Other treatments: Incineration, metals recovery, fuel blending, sludge treatment, stabilization, land treatment/application, etc Aqueous treatment 12% Total managed waste =43.9 m tons Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 Data)

34 Quantity of RCRA Hazardous Waste Managed, by Management Method, only waste received from out side Other treatments 21% Landfill/surface impoundment 17% Storage and/or transfer 7% Metals recovery 14% Incineration 6% Other disposal 11% Other treatments: Stabilization, deepwell or underground injection, aqueous treatment, solvents recovery, sludge treatment, land treatment/application etc. Fuel blending 12% Energy recovery 12% Total managed waste =8.5 m tons Source: The National Biennial RCRA Hazardous Waste Report (Based on 2005 Data)

35 Universal Waste System Designed to ease the burden on generators, transporters, and recyclers of certain high volume hazardous wastes that are easily recyclable. Types: Certain pesticides Mercury lamps Mercury switches Certain batteries Hg Thermostat Hg Lamps Batteries

36 Household Hazardous Waste Examples of HHW: Paint and paint related products Pesticides Pool chemicals Drain cleaners Nail polish/remover Furniture refinishers Glass cleaners Insect repellent Car care chemicals

37 Other Waste Types Asbestos Some types of waste are clearly hazardous in nature, but are not governed under RCRA Asbestos PCBs PCB Capacitor PCB Ballast

38 Challenges Promoting recycling of hazardous waste without increasing harm to human health and the environment Ensuring that hazardous wastes are not dumped on other countries

39 Challenges Determining the appropriate use of the TCLP. The TCLP can at times both underestimate and overestimate the leaching that will actually occur in a landfill. Iron-based Water Treatment Sludge Lead-containing Electronic Devices

40 Leach Leaching using TCLP and Landfill Leachate TCLP MSW Leachate Lead (mg/l) n = 12 n = 12 n = 9 CRT Glass PWBs Cell Phones

41 Waste Lift Waste Lift Waste Lift Cell Phones and Ni-Cd Batteries Keyboard and Mouse Monitor CPU Smoke Detectors Waste Lift A University of Florida study is looking at electronic device leaching in landfills. Waste Lift River Rock

42 Contact Information: