On-line Sorting Technologies for CCA Treated Wood July 24, 2001

Objective To design and implement an automated system to effectively sort CCA-treated wood from other wood types at C&D facilities

Project Tasks Task 1: Construct Shelter Task 2: Construct Conveyor Task 3: Lab Test and Develop Detector Task 4: Install and Field Test Conveyor & Detector Task 5: Operate Sorting System and Document Performance

SHELTER

Participants Metal shelter design, fabrication and assembly – Trident Concrete slab design – Sarasota County Concrete form, control room – Meyer and Gabbert Concrete pour, anchor bolts and project management – Anderson and Ellis Electrical – Claxton Electric

***Control room and final electrical wiring installed on January 23, 2001

Shelter Completed in January 2001 Interior control room built with recycled materials (from on-site) by Meyer and Gabbert Electrical installation will continue with wiring for conveyor and control room

Control Room

CONVEYOR

CCA-TREATED WOOD INCLINE CONVEYOR OTHER WOOD TYPES ROLL-OFF 30’ 2.5’ 4.5’ 2.5’ 10’ 26’ 5’ 10.5’ Horizontal Guide to Align Wood 1’ Electric Panel for Conveyor ROLLER CONVEYOR BELT CONVEYOR 40’ North Incoming Mixed Wood SPUR CONVEYOR 7’ Roof Support Column 10’ 45 o 4’ Shear Arm Conveyor Layout: February 6, 2001 Control Room

Conveyor – Cross Section

Removable Roller Spur Conveyor Mounting For Shear Arm

Wood Sort Pallet Study 100 pallets tested and 0 were CCA-treated Wood Sort 3 construction piles and 1 demolition piles were sorted

Wood Sort

Waste Pile 1

Waste Pile 2

Waste Pile 3

Waste Pile 4

DETECTORS laser x-ray

Laser Induced Breakdown Spectroscopy (LIBS) Pulsed Laser Atomic Emission Collection Fiber Optic Spectrometer Laser Induced Plasma Wood Sample Line position provides species identification Wavelength (nm) Intensity Ca Cr Ca

Field Unit

July 3rd Field Trial Increased the internal spectrometer gain Conducted sorting trial to determine: –Accuracy of the detector –Accuracy of the human observer Single-shot spectra collection –Determine thresholds and accuracy

Chromium Peak and Base Intensities

Average Peak-to-Base Ratios

Peak-to-Base Ratios on a Shot-by-Shot Basis

Single-Shot Analysis

Analysis of Results Flexibility of the LIBS detector –Settings can be optimized for extremely rapid analysis and accurate analysis –Different settings for different disposal paths Field trials demonstrate: –Accuracies that would allow burning or mulching of wood identified as untreated –Identification of painted wood –Can accurately differentiate CCA from alternates

X-Ray Fluorescence Technology Proven to work well and has been used extensively by many wood treating plants to test retention levels. Standardized by the AWPA. Using the Spectro/Asoma model 400 unit (different from the wood treatment industry).

Theory of X-Ray Fluorescence Incident X-ray from the analyzer strikes an electron occupying the lowest shell Electron is ejected An upper-shell electron drops down to fill the vacancy X-ray characteristic to this elements’ energy is emitted Incident X-Ray Ejected e- Emitted X-Ray Transitioned e- Nucleus

XRF Field Photos ¾”

Treated vs. Untreated Wood

Dry vs. Wet Treated Wood

Dry vs. Wet Untreated Wood

Alternative Chemicals

Heartwood vs. Sapwood

Distance readings

Summary Advantages –Very consistent. –It can not only differentiate between treated and untreated wood but gives the actual amount treated in specific units. Disadvantages –Non-customized equipment Hit analyze key  long print time. –Limited to no more than 1” distance. –Due to the radiation, a minimum 6” radial distance must be maintained at all times.

Questions