Wood Preserving - Trainex Preserving Objectives ... 69.3 16.0 – 20.9 14.7 – 19.7 Type B Standard...

Wood Preserving

Wood Preserving Objectives

• List three major chemical preservative systems

• List key chemicals associated with wood preserving

• Describe the pressure treating process

• List major modes of release to the environment

• Identify analytical methods useful for detecting wood preservative contaminants in the environment

Wood Preserving Overview

• Active in U.S. for over 100 years• Produces treated lumber and wood

products which resist degradation • High percentage of small businesses• Many facilities closed, abandoned or failed to comply with

“new” industry-specific RCRA regulations (1990)– wastewaters listed as hazardous waste – Drip pads and other improvements required

Process Overview

• SIC: 2491, NAICS 321114

• Used by construction, railroad, and utilities industries

• 6.5 billion board ft / yr (2000)

• 486 U.S. facilities (1992)

• 307 employ 20 or fewer

• 90% by pressure treating process

Major Chemical Preservative Systems• Organic (oil-borne) Creosote (15%) Pentachlorophenol (PCP) (6%) systems

• Inorganic (water-borne) (78%) Chromated copper arsenate Ammoniacal copper-zinc-arsenate (ACZA) Ammoniacal copper arsenate (ACA) Ammoniacal copper quarternary (ACQ)

Video – Chemical Preservatives

Key Chemicals

Arsenic - “CCA” constituent, toxic and prevalent

Oil – diluent/lubricant/fuel, contains VOC’s, including BTEX

Creosote – preservative, mixture of SVOC’s, a.k.a. “cancer in a bucket”

Chromium – “CCA” constituent, toxic (especially Cr+6)

PCP – preservative, chlorinated SVOC, solid unless “oil-borne”

Zinc – “ACZA” constituent, less toxic, less prevalent

Dioxins / furans – toxic chlorinated SVOC “family”, 2,3,7,8-TCDD “Godfather”

Copper – “CCA” constituent

Diesel oil – preservative diluent

Standard Process SchematicVACUUM & BOILER EMISSIONS,

BLOWDOWN, VOCs, AMMONIA, AIRBORNE ARSENICS, ETC

UNTREATED LUMBER, PCP, CREOSOTE, CCA, ETC.

STEAM, DIESEL OIL, COAL TAR, PETROLEUM OIL,

ETC.

TREATED LUMBER

PCP, CREOSOTE, CCA (RECYCLED)

CONTAMINATED DEBRIS, FILTERS, METAL- BEARING SLUDGE, ORGANIC SLUDGE, SPENT CARBON

CHROMIUM, PAHs, ARSENIC, ZINC

RM

R

P

B

W

Sump

Curbs

Drip pad

Charging area

Paved containment areaDrainage

Vacuumpump

Vent

Retort Cylinder

ExteriorLoading

Effluent

HighPressurepump

Working solution

Process Water

TankerLine

Concentrate

Storage of freshly treated wood

Pressure Treating Process Details

12

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder

ExteriorLoading Filters

Effluent

Concentrate50 – 60% CCA

Transfer line


CCA Process Description - Bethell or Full-Cell Process

Video – Drying Methods

Video – Retort

17

Sump

Curbs

Drip pad

Charging area

Paved containment area

Vent

Retort Cylinder


Effluent

HighPressurepump

Working solution

ConcentrateTransfer line

Drainage

Vacuumpump


Step 1: Preparation

18

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder


Effluent

WorkingSolution


Process water

Pressure = 1 atmTemperature = 70°F


Step 1: Preparation1 – 2% CCA Mold Inhibitor

19

Sump

Curbs

Drip pad

Charging area


Retort Cylinder


Effluent

WorkingSolution


Pressure = ~3 in Hg absoluteTemperature = 70°F

Process Water

TankerLine

HighPressurepump


Step 2: VacuumVent

Vacuumpump

21

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder


Effluent

WorkingSolution


Pressure = 175 psi (5-8 min.)Temperature = 70°F

Process Water

TankerLine

HighPressurepump


Step 3: Pressurization

22

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder


Effluent

Working solution Working

Solution


Pressure = 175 psi to 1 atm (up to 2 hours)Temperature = 70°F

Process Water

TankerLine

HighPressurepump


Step 4: Depressurization

23

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder


Effluent

HighPressurepump


Solution


Pressure = 1 atm to 20 in HgTemperature = 70°F

Process Water

TankerLineStorage of

freshly treated wood

Step 5: Final Vacuum

24

Sump

Curbs

Drip pad

Charging area


Vacuumpump

Vent

Retort Cylinder


Effluent

HighPressurepump


SolutionConcentrate

Transfer line


Process Water

TankerLineStorage of

freshly treated wood

Step 6: Charge Unloading

25


Sump

Curbs

Drip pad

Charging area

Paved containment area

Vacuumpump

Vent

Retort Cylinder


Effluent

HighPressurepump


Solution



Drainage

Step 7: Repeat the Cycle

PreservativeChromium (VI)

as CrO3Copperas CuO

Zincas ZnO

Arsenicas As2O5

Compound (%)

CCAType A

Standard 65.85 18.1 16.4Range 59.4 – 69.3 16.0 – 20.9 14.7 – 19.7

Type BStandard 35.3 19.6 45.1Range 33.0 – 38.0 18.0 – 22.0 42.0 – 48.0

Type CStandard 47.5 18.5 34.0Range 44.5 – 50.5 17.0 – 21.0 30.0 – 38.0

ACZAStandard 50.0 25.0 25.0Range 45.0 – 55.0 22.5 – 27.5 22.5 – 27.5

Source: American Wood Preserver’s Association, 1992

CCA and ACZA Formulations

ComponentCommercial(Dowcide 7)

Purified(Dowcide EC-7)

Analytical Results

PentachlorophenolTetrachlorophenolTrichlorophenolChlorinated phenoxyphenolOctachlorodioxinHeptachlorodioxinHexachlorodioxinOctachlorodibenzofuranHeptachlorodibenzofuranHexachlorodibenzofuran

88.4%4.4%0.1%6.2%2500 ppm125ppm4 ppm80 ppm80 ppm30 ppm

89.8%10.1%0.1%--%15 ppm6.5ppm1 ppm1 ppm1.8 ppm1 ppm

Source: EPA 1978

Composition of Commercial Grade and Purified Grade Pentachlorophenol

Higher chlorophenolsPentachlorophenol

Technical PCP Constituents

2,3,5,6 - Tetrachlorophenol Dioxin (octa, traces of hepta, and hexachlorodioxin)

OHCl

ClCl

Cl

Cl85–90%

Cl

ClCl

Cl

OOH

Cl Cl

Cl Cl

Cl2–6%

OHClCl

ClCl

4–8% ClCl

ClCl

ClCl

ClClO

O~ 0.1%

Major Chemical Components of Creosote Produced in the U.S.

Naphthalene 3.0 - 17.0Methyl naphthalene 2.1 - 10.0 Diphenyl dimethylnaphthalene --Biphenyl 0.8 - 1.9Acenaphthene 7.6 - 9.0Dimethylnaphthalene 2.0Diphenyloxide --Dibenzofuran 5.0Fluorene-related compounds 6.0 - 10.0

Methyl Fluorene 3.0Phenanthrene 21.0 Anthracene 2.0Carbazole 2.0 - 5.1Methylphenanthrene 3.0Methylanthracenes 4.0 Fluoranthene 10.0 - 11.8Pyrene 8.5Benzofluorene 2.0Chrysene 3.0

Source: EPA 1990, 1992 *Volume may vary significantly

Compound or Component Percentage* Compound or Component Percentage*

Structure of the Major Components of Creosote

Naphthalene

FluorantheneCH2 – CH2

Acenaphthene

Phenanthrene

Pyrene

Benzene 78.1 1800 mg/l 0.88 95 80

Naphthalene 128.2 31 mg/l 1.0 .085 218

Pyrene 202.3 0.14 mg/l 1.3 4.6 x 10-6 404

Chrysene 228.3 0.0016 mg/l 1.3 6.2 x 10-9 448

Benzo(a) Anthracene 228.3 0.009 mg/l n/a 1.1 x 10-7 n/a

CompoundMolecular

WeightSolubility(@ 20° C)

SpecificGravity

VaporPressure*

(torr)

BoilingPoint(°C)

Source: Superfund Chemical Data Matrix for Windows, version 1.0, September 1997

Physical Properties of Creosote Compounds

* @ 20° C.

Video – Wastewater F Codes

• Wastewaters (ww), process residuals, drippage– F032 - PCP processes– F034 - Creosote processes– F035 - Inorganic preservatives

– K001 - Bottom sediment sludge from ww processes for creosote and / or PCP facilities

Modes of Release - Hazardous Waste Streams

Video – Wastewaters

WasteDescription: K001-C (Creosote type)

Allied Chemical’s Birmingham, AL Plant, Bottom Sediment Sludge

Analysis: Soil 30.0%Water 20.0Wood Chips 10.0Naphthalene 4.0Phenanthrene 3.5Fluoranthene 2.5Other active organics 30.0

100%

Ash content 12 – 51%Heating value 10,000 – 11,000 BTU/lbVolatile matter 57 – 81%

Modes of Release - Typical Hazardous Waste Composition

*Tetra- and pentachlorophenols, benzene, toulene, and PAHs

WasteDescription: K001-C Pentachlorophenol (PCP) Type

Allied Chemical’s Richton MS Plant, Bottom, Sediment Sludge

Analysis: Soil 40.0%Water 30.0Wood Chips 10.0Active organics* 20.0

100%

Ash content 12 – 51%Heating value 3,800 – 8,300 BTU/lbPCP 970 – 3,800 ppm

Modes of Release - Typical Hazardous Waste Composition

Modes of Release

Other Release Sources

• Retort outwash

• Drip pad / storage pad drippage, a.k.a. “kick back”

• Off-loading spills

• Stormwater runoff

• Discarded, unused commercial products (F027, U051, P011, etc.)

Video – Kickback

• Characteristic wastes– D004 - Arsenic– D007 - Chromium– D018 - Benzene– D037 - PCP

• Discarded, unused commercial products– F027 - PCP– U051 - Creosote– Inorganics, e.g., arsenic

pentoxide

Modes of Release - Hazardous Waste Streams

Video – Broken & Discarded Treated Lumber Pieces

Analytical ConsiderationsLaboratory Methods• Inorganic

– Total metals: AA or ICP– TCLP for RCRA characteristic

• Creosote– Analyze for PAHs– HPLC or GC / MS

• PCP– SW-846 8250 / 8270– TCLP

Analytical Considerations

Field Screening Methods

• Inorganic– X-ray fluorescence (XRF)

• Organics– Immunoassay test kits (PCP, PAH, TPH, etc.)– Portable GC or GC/MS

Wood Preserving Summary

• List three major chemical preservative systems

• List key chemicals associated with wood preserving

• Describe the pressure treating process

• List major modes of release to the environment

• Identify analytical methods useful for detecting wood preservative contaminants in the environment

Wood Preserving - Trainex Preserving Objectives ... 69.3 16.0 – 20.9 14.7 – 19.7 Type B Standard...

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Transcript of Wood Preserving - Trainex Preserving Objectives ... 69.3 16.0 – 20.9 14.7 – 19.7 Type B Standard...