Emerging Technologies in Hazardous Waste Management Downloaded from pubs.acs.org by UNIV OF CALIFORNIA SANTA BARBARA on 09/19/18. For personal use only.
Chapter 15 E v a l u a t i o n of W o o d - T r e a t i n g P l a n t Sites for L a n d Treatment of Creosote- a n d P e n t a c h l o r o p h e n o l - C o n t a m i n a t e d Soils Hamid Borazjani, Brenda J. Ferguson, Linda K. McFarland, Gary D. McGinnis, Daniel F. Pope, David A. Strobel, and Jennifer L. Wagner Mississippi Forest Products Laboratory, Mississippi State University, P.O. Drawer FP, Mississippi State, MS 39762 Creosote and pentachlorophenol contaminated soils at eight wood-treating plant sites in the southeastern United States were evaluated and found suitable for remediation by land treatment. The first phase of the study included characterization of the chemical, physical, and morphological properties of the soil, levels of pentachlorophenol and polynuclear aromatic hydrocarbons, and an evaluation of the history of treating operations at the site. The second phase included studies of the rates of degradation and soil transport of pentachlorophenol and polynuclear aromatic hydrocarbons. Creosote and pentachlorophenol have been widely used to treat wood products to increase their resistance to decay. Before strict environmental regulations were instituted, common practices at wood treating plants resulted in the release of substantial amounts of creosote and pentachlorophenol wastes into the environment. Exudation of treating solutions from freshly treated wood, accidental spills, and disposal of waste treating solution sludges in earthen pits were the major contributors to pollution. There are thousands of wood-treating plant sites in the United States, and most of them have contaminated soil and waste sludges to be cleaned up. One method that could be used for remediation of these sludges and contaminated soil is land treatment. Land treatment uses the microbiological, chemical and physical processes occurring in soil to immobilize and transform organic wastes to simpler, less toxic forms. Although waste sludges could be applied to clean soil to be transformed, land treatment techniques are usually used to remediate previously contaminated soil. In order to use land treatment for a particular waste, two questions must be answered: 1) Are the waste compounds transformed in the soil? and 2) Are the waste compounds retained in the active 0097-6156/90/0422-0252$06.00/0 © 1990 American Chemical Society
15.
BORAZJANI ETAL.
Treatment ofContaminated Soils
253
treatment zone long enough for complete transformation? The second question concerns the tendency of the waste compounds to move down through the s o i l (migration) along with the flow of s o i l water. Most transformation takes place i n the top 50 to 100 centimeters of s o i l , probably because of the greater supply of oxygen there. Transformation below this zone i s often very slow, and may not be fast enough to prevent contamination of the deep subsoil. If transformation does occur and the waste compounds are retained i n the active treatment zone long enough for acceptable treatment to take place, then land treatment can be considered a viable alternative for disposal of the waste i n question. This paper reports the results of the f i r s t and second phase of a three-phase study to evaluate the e f f i c a c y of land treatment as an on-site management alternative for waste sludges and contaminated s o i l containing pentachlorophenol and creosote from wood-treating f a c i l i t i e s . During the f i r s t phase, the chemical and physical c h a r a c t e r i s t i c s of the s o i l and waste sludges at eight wood-treating plant s i t e s were evaluated. During the second phase, laboratory experiments were conducted to determine the potential for transformation of creosote compounds and pentachlorophenol i n the s i t e s o i l s and to determine the potential for migration of these compounds i n the site s o i l s . Work on four of the sites i s now complete and a summary of the results i s reported here. The third phase (currently i n progress) involves a f i e l d evaluation study at one of the wood-treating plant s i t e s . Methods Site Studies. Eight wood-treating plant sites i n the southeastern United States were selected for study (Table I ) . The sites were chosen so that they could be used for a f i e l d evaluation study, which required that: 1) An area of 1/2 to 1 acre be available for use i n the f i e l d evaluation, 2) the s i t e must have a source of waste sludges, 3) the site should have had a low l e v e l exposure to creosote or pentachlorophenol so that an acclimated microflora i s available, but the site should be without high l e v e l s of contamination i n the treatment zone, and 4) a means of disposal of runoff water be available. A general history of treating operations at each s i t e was taken. A study of the chemical, physical, and morphological characteristics of each s i t e s o i l was done using standard methods (1). Part of the results are shown i n Table I. The s o i l and sludges were analyzed for seventeen creosote components (polynuclear aromatic hydrocarbons, PAHs), pentachlorophenol, and other chemical characteristics (Tables II-V) using standard EPA recommended techniques for extraction, cleanup and analysis - Method Nos. 3540, 3520, 3630, 8100, 8040 (2). Transformation Studies. F i f t y kilogram samples of s o i l from each site were transported i n insulated (but open to a i r ) containers to the laboratory where they were kept cool (20°C) and moist u n t i l used. The s o i l s were sieved to remove rocks and coarse plant materials. Dried, ground chicken manure was added to a l l s o i l s at 4% by weight. This addition accomplished several objectives. The manure furnished: D a carbon source for potential co-metabolism,
Pentachlorophenol Creosote
Creosote
Pentachlorophenol Creosote
Pentachlorophenol Creosote
100 acres 80 years
100 acres 15 years
—
15 acres 63 years
—
125 acres 61 years
76 acres 62 years
Gulfport, MS
Wiggins, MS
Columbus, MS
Atlanta, GA
Wilmington, NC
Meridian, MS
Chattanooga, TN
Southern Appalachian Ridges and Valleys
Southern Coastal Plain
Atlantic Coast flatwoods
Southern Piedmont
Southern Coastal Plain
Southern Coastal Plain
Eastern Gulf Coast flatwoods
Southern MS Valley silty uplands
Major land resource areas
'These samples were taken from the surface to a depth of 5 inches.
Creosote
Pentachlorophenol Creosote
Pentachlorophenol Creosote
Pentachlorophenol Creosote
100 acres 78 years
Grenada, MS
Preservative used
Size & age of plant
Site location
Urban land complex
Stough sandy loam
Urban land
Urban land
Latonia loamy sand
8.4 40.22
31.4 46.77
60.2 13.01
2.5
—
3.55
3.29
14.08
6.0
—
—
a
13.77
Clay
91.5
16.42 80.03
24.16
72.55
McLaurin sandy loam
28.88
57.04
Smithton sandy loam
a
70.17
Silt
Weight %
16.06
Sand
a
Grenada s i l t loam
Soil
Table I. Characteristics of the Eight Sites Used in This Study
ND ND ND ND ND ND
0-10 10-20 20-30 30-40 40-50 50-60
1.78 ND ND ND ND ND
0.112 ND ND ND ND ND
Gulfport
ND ND ND ND ND ND
20.64 0.088 0.130 0.147 0.319 —
0.33 ND ND ND ND ND
195.9 27.45 ND ND ND ND
110.81 ND ND ND ND ND
(ppm)
193.3 40.55 43.94 — — —
b
1.418 0.218 0.209 — — —
Columbus Atlanta Wilmington Pentachlorophenol (ppm i n s o i l )
Total p o l y c y c l i c arotnatics i n s o i l
0.389 0.017 ND ND ND ND
Wiggins
ND ND ND ND ND ND
0.129 0.090 0.096 0.104 0.053 —
Meridian
121.76 ND ND ND ND
0.288 0.099 0.090 0.074 0.057 —
Chattanooga
S o i l Concentration of PCP and PAHs at the Proposed F i e l d Evaluation Sites
ND = not detected. ^The t o t a l concentration of 16 polycyclic aromatic hydrocarbons (naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, biphenyl, acenaphthylene, acenaphthene, dibenzofuran, fluorene, phenanthrene, anthracene, carbazole, fluoranthene, pyrene, 1,2-benzanthracene, chrysene, benzo(a)pyrene, benzo(ghi)perylene.
a
ND ND ND ND ND ND
a
Grenada
0-10 10-20 20-30 30-40 40-50 50-60
Depth (inches)
Table I I .
w
| fc« e? &
?
^ & | ^
£
Ο
1.11 1.38 23.35 42.42 35.68 4.45 7.14 64.44 1.73 16.91
74.58 30.62 36.07 31.56 36.52 34.44 69.10 26.60 48.27 67.35
6.30 4.80 3.00 3.50 5.70 5.90 5.00 7.20 4.00 7.10
pH
Total phenolics (%) .0041 .0097 .0045 .0130 .0171 .0224 .0120 .0007 .0114 .0003
Total organic carbon (%) 7.37 22.50 37.85 49.45 36.03 49.79 25.33 4.02 31.96 14.61
9.74 44.03 15.86 22.57 17.90 44.60 14.17 .044 35.34 3.68
Oil and grease (%)
Composition of the Sludges; a
6,699 5,656 29,022 30,060 1,893 NDS 51,974 ND 13,891 ND
Pentachlorophenol (ppm)
e
96,078 101,023 20,463 47,075 114,127 475,372 119,546 10,007 119,124 72,346
e
c
e
f
Polycyclic aromatic hydrocarbons » (ppm)
Values based on the starting weight of sludge. ^Lagoon contains mainly pentachlorophenol. Lagoon contains mainly pentachlorophenol in a heavy o i l . Lagoon contains mainly creosote. This sludge was used in the transformation and migration studies. These values are the means of two replicates and are determined on a dry basis. A l l were determined by capillary column gas chromatography. Total of the 17 major polycyclic aromatic hydrocarbons found in creosote. 8ND = not detected.
a
d
C
b
Grenada Gulfport Wiggins # l Wiggins *2 Wiggins #3 Columbus Atlanta Wilmington Meridian Chattanooga
Inorganic solids (%)
Water content (%)
Table III.
en
a
were o b t a i n e d
Acenaphthene
=
values
Naphthalene 2-Methylnaphthalene 1-Methylnaphthalene Biphenyl Acenaphthylene
= = = = =
These
Ν 2Mn lMn Bi Ac Ace
Chattanooga
= = = = = =
by GC/MS.
Di Fl Ph An Ca Flu
Dibenzofuran Fluorene Phenanthrene Anthracene Carbazole Fluoranthene Py 1,2B Ch Bz Bzg = Chrysene = BenzoCa)pyrene = Benzo(ghi)perylene Pentachlorophenol
= Pyrene = 1,2-Benzanthracene
550 ND
1350 ND 200
2100 3550 870
SP
nt of Coniai ninated
200
4800 2200
11700
20000
2050
2200
5400
1150
ND
445
585
815
1200
6550
29500
7350 1415
6850
5150 1230
1800
1650
2700
5350
16500
I
Treai
Meridian
ND ND 150
150 430 840
190
1525
1550
585
425
400
ND
ND
185
330
350
BORAZ;FANI ET AL.
Wilmington
8050
18000
16000
16500
2800
6600
11500
23000
39400
1100
5800 3400
15500
23000
Atlanta
6850
3500 17000 12500 38000
49500
9550
24500
12500
23000
53000 45000
34000
32500
31000
7650
10500
16500
29500
70500
Columbus
ND 580 6000 3850
19000
22500
4250
14500
34000
14000
11500
13000
2000
3500
6350
12000
17500
#3
Wiggins
ND 2400 1300
7500
11500
2650
8150
21000
7450
6050
5550
1050
1900
4000
7450
10200
#2
Wiggins
ND 75 355
495 185
1500
2150
570
2550
5000
1750
1300
1550
215
535
1400
2450
3400
#1
Wiggins
b
ND
9600
10150
2635
3000
1050
7450
14000
13500
Gulfport
3600 3650
5050
Bzg
5850
Bz
2050
Ch
3250
1,2B
12500
17000
2100
7200
30000
Py
19500
27000
3450
15000
43000
18000 10250
Flu
17000
Ca
21500
An
5250
Ph
5850
13250
24150
67000
Grenada
(ppb)
Di
Ace
Ac
lMn
2Mn
Ν
Fl
PAH C o m p o s i t i o n o f S i t e S l u d g e s
Bi
T a b l e IV.
15.
t 1/2 (days)
1 1 1 1 1 8 4 4 50 68 43 248 NT NT 301 NT ND NT
! 1 1 1 1 2 3 3 11 35 30 29 100 122 61 NT ND 334
NT = no transformation observed. *ND not detected.
a
b
Upper limit
Lower limit
0.33% Loading
14 7 3 5 9 25 2 31 25 NT 75 289 433 578 365 NT NT NT
t 1/2 (days)
10 4 3 3 5 17 17 22 17 NT 48 165 187 173 173 ΝΓ NT NT
Lower limit
1.0% Loading
28 29 4 10 NT 50 28 52 50 NT 169 1155 NT NT NT NT NT NT a
Upper limit
14 24 39 57 112 124 147 224 578 173 90 107 99 315 98 NT 158 385
t 1/2 (days)
11 19 28 30 89 96 99 169 173 96 62 67 62 82 47 NT 61 248
Lower limit
3.0% Loading
Half Lives and 95% Confidence Limits of PAHs and PCP i n Columbus S o i l Loaded with Site Sludges at 0.33, 1.0, and 3.0% by S o i l Dry Weight
Naphthalene 1 2-Methylnaphthalene 1 1-Methylnaphthalene 1 Biphenyl 1 Acenaphthylene 1 Acenaphthene 4 Dibenzofuran 3 Fluorene 3 Phenanthrene 18 Anthracene 46 Carbazole 35 Fluoranthene 53 Pyrene 231 1,2 Benzanthracene 347 Chrysene 102 Benzo-a-pyrene NT ND Benzo-ghi-perylene 1087 Pentachlorophenol
Compounds
Table V.
21 33 61 578 147 169 301 347 NT 866 169 267 248 NT NT NT NT 758
Upper limit
15.
BORAZJANI ETAL.
Treatment ofContaminated Sous
259
which has been found i n at least some instances to be an important component of the transformation process (3); 2) both major and minor nutrients; and 3) a wide variety of microbes that were potentially important biodegraders. Also, added organic matter should markedly decrease mobility of hazardous constituents i n applied organic wastes, which i s highly desirable i n a land treatment operation (4,5). Previous f i e l d experience i n landfarming operations (unpublished data) indicated that addition of manures was b e n e f i c i a l , so the effect of adding manures was not s p e c i f i c a l l y studied ( i . e . , with no-manure controls) i n the research reported here. Although other animal manures might serve as well, chicken manure was chosen for study because i t i s readily available i n many parts of the United States. A t y p i c a l analysis of the chicken manure used i n this study i s given below: Total organic carbon = 8.97% Total nitrogen = 1.35% Total phosphorous = 0.12% Samples of the sludges from each s i t e were taken from several locations i n the sludge pits and mixed together to give a representative sludge from each s i t e . Sludge was added to the s o i l at loading rates of 0.3%, 1.0%, and 3.0% (sludge wet weight/soil dry weight) with three replications of each s i t e soil/loading rate combination. Refer to Table III f o r sludge composition. The experimental unit was a brown glass container with a l i d , containing 500 g (dry weight) of s o i l mixed with sludge. The sludge from each s i t e was tested i n the s o i l from that s i t e . For sludges with no pentachlorophenol, reagent grade pentachlorophenol i n methanol was mixed with the s o i l at 200 ppm pentachlorophenol by weight. The s o i l moisture content was adjusted to 70% of water-holding capacity. The water holding capacity was determined by saturating the s o i l with water, allowing the s o i l to drain for 24 hours, and then drying at 105°C. Water was added weekly to each experimental unit as needed to maintain the 70% moisture content. A l l the units were kept i n a constant temperature room (22° +_ 2°C) for the duration of the study. The s o i l i n each unit was mixed each week by s t i r r i n g with a spatula, to simulate t i l l a g e operations commonly used i n landfarming. At 0, 30, 60, and 90 days 40 gram samples of the s o i l i n each dish were taken for chemical analysis. The analyses were conducted according to the standard EPA methods referred to e a r l i e r (2). Transformation rates and upper and lower confidence l i m i t s for the transformation rates were calculated with a l i n e a r regression using f i r s t order kinetics. Half l i v e s were calculated from the transformation rates. Migration Studies. Eighteen undisturbed s o i l cores were taken at each s i t e for the migration studies. A stainless steel cylinder (22 cm diameter χ 76 cm long) lined with a section (18 cm χ 60 cm) of high density polyethylene pipe ( P h i l l i p s Driscopipe) was driven into the s o i l . This produced an undisturbed s o i l core (18 cm χ 51 cm) enclosed i n the section of pipe.
260
EMERGING TECHNOLOGIES IN HAZARDOUS WASTE MANAGEMENT
In the laboratory the s o i l cores were placed on a rack with each core resting on a fiberglass mat supported by a stainless steel screen set i n a large glass funnel. Each s o i l core was tested as follows: 1) A solution of 500 ml of 500 ppm NaCl i n water was poured on the top of each core; 2) after this solution entered the s o i l , water was put on top of each core p e r i o d i c a l l y ; and 3) the water draining from the bottom of each core was collected i n 500 ml increments and tested for CI" concentration. The twelve cores from each s i t e showing the sharpest, most uniform CI" 'peak' were chosen for the migration studies. Half the s o i l cores from each s i t e were randomly chosen as controls to measure background levels of creosote compounds and PCP. A l l the cores had the top 15 cm of s o i l removed, pulverized and mixed with chicken manure (4% by weight). The s o i l was replaced i n the control cores without further modification. In the remaining cores from each site the s i t e sludge was mixed with the removed s o i l at 3% by weight, and the removed s o i l was replaced i n the s o i l cores ('loaded c o r e s ) . For site sludges with no pentachlorophenol, pentachlorophenol was added to the removed s o i l at 200 ppm by weight. Water was added to each core at a rate equivalent to 5 cm r a i n f a l l each week (1300 ml/core/week). The water draining from each core was sampled and analyzed at monthly i n t e r v a l s . After three months, each s o i l core was sectioned into 6 equal portions and each portion was analyzed to determine how far the sludge components had moved down through the core. 1
Results and Discussion Site Studies. A summary of the general s i t e characteristics i s given i n Table I. Most of the sites are old sites and had extensive areas of contamination. A l l but two sites recorded use of both pentachlorophenol and creosote i n their wood treating operations. Records at most plant sites were very sketchy. The s o i l types varied from a heavy clay at Chattanooga to an almost pure sand at Wilmington. The s o i l s at the proposed f i e l d evaluation sites had low to moderate levels of contaminants except the Grenada s i t e , where no contamination was detected (Table I I ) . The more mobile pentachlorophenol was detected as deep as 50 inches i n three s o i l s , but creosote components (PAHs) were found only i n shallow layers. Note that these results apply only to the area at each site that was chosen for a possible f i e l d evaluation study, not to heavily contaminated areas at the s i t e s . The composition of the sludges used i n the study i s shown i n Tables III and IV. Sludge composition varied widely. Water was a major component of a l l the sludges since they were stored i n open p i t s . Inorganic solids from s o i l were prominent i n several sludges. The pH of several of the sludges was low, p a r t i a l l y due to a high pentachlorophenol content (6). The o i l c a r r i e r s used to help the preservative penetrate the wood i n the treating process caused the o i l and grease content of the sludges to be high. The o i l can cause d i f f i c u l t y i n land treatment by reducing the access of oxygen to the preservatives, thereby reducing aerobic microbial a c t i v i t y . The o i l c a r r i e r s can also increase the mobility of preservative compounds i n the s o i l .
15.
BORAZJANI ETAL.
Treatment of Contaminated Soils
261
The pentachlorophenol and PAH contents of the sludges varied widely. A pentachlorophenol treating solution usually contains about 70 to 80,000 ppm pentachlorophenol, and a creosote treating solution may contain 400 to 500,000 ppm PAHs. Therefore i f the water was removed, some of the sludges would be similar i n concentration to an actual treating solution (Table I I I ) . The major PAHs i n the sludges are shown i n Table IV. The chemical composition of creosote sold for wood-treating purposes varies considerably, and creosote i s usually described by i t s physical properties ( d i s t i l l a t i o n fractions) rather than by chemical content. The chemical v a r i a b i l i t y of the sludges i s due to their i n i t i a l v a r i a b i l i t y , their use and reuse i n wood treating, and subsequent exposure to the environment f o r several years i n sludge pits. The major PAHs i n sludges are two, three, four, f i v e , and six ring compounds, with the two, three, and four ring compounds accounting f o r the greater portion. Both t o x i c i t y and resistance to transformation increase as the number of rings increase. Transformation Studies. The t o t a l PAH breakdown was similar i n s o i l s from a l l four sites i f similar loading concentrations were used (Tables V-VII). The individual PAHs can be divided into three groups according to the results of t h i s research: those with apparent half l i v e s of ten days or l e s s , those with apparent half l i v e s of one hundred days or less, and those with apparent half l i v e s of more than one hundred days. Naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, biphenyl, acenaphthalene, acenaphthene, dibenzofuran, and fluorene usually had apparent half l i v e s of ten days or l e s s . Phenanthrene, anthracene, carbazole, and fluoranthene usually had apparent half l i v e s between ten and one hundred days. Pyrene, 1, 2-benzanthracene, chrysene, benzo-a-pyrene, and benzo-ghi-perylene usually had apparent half l i v e s greater than one hundred days. In several cases these l a s t f i v e compounds showed essentially no transformation within the time frame of the experiment. The transformation rates of i n d i v i d u a l PAHs were apparently related to molecular size and structure, as noted i n previous studies (4^). The zero to ten day half l i f e group contained compounds with two aromatic rings, the ten to one hundred day half l i f e group contained compounds with three aromatic rings, and the one hundred plus day half l i f e group contained compounds with four or more aromatic rings. However, some of the larger, most r e c a l c i t r a n t compounds apparently were transformed readily i n some s o i l s (Note Tables VI-VII). This indicates that even the most persistent PAHs might be remediated with land treatment i f further study could elucidate the precise conditions necessary for consistent r e s u l t s . Carbazole, a compound containing a nitrogen bridge between two aromatic rings, varied greatly i n persistence i n different s o i l s and loadings. This may be due to the nitrogen atom affecting water s o l u b i l i t y and other properties of carbazole under varying l o c a l oxidation/reduction potentials and pH.
1 1 1 1 23 9 9 11 18 NT 5 91 95 NT 866 NT NT 55
1 1 1 1 2 3 3 3 3 5 2 51 53 169 95 433 126 39
1 Naphthalene 1 2-Methylnaphthalene 1-Methylnaphthalene 1 1 Biphenyl 4 Acenaphthylene 4 Acenaphthene 4 Dibenzofuran 4 Fluorene 5 Phenanthrene 10 Anthracene 3 Carbazole 65 Fluoranthene 68 Pyrene 1,2 Benzanthracene 3466 173 Chrysene 3466 Benzo-a-pyrene 770 Benzo-ghi-perylene 46 Pentachlorophenol
*NT no transformation observed. ND = not detected.
b
a
Upper limit
Lower limit
Compounds
t 1/2 (days)
0.33% Loading
I 1 1 1 1 1 1 1 2 27 1 36 45 107 102 NT NT 53
t 1/2 (days) !
1 1 1 i 1 1 1 17 45 1 65 86 285 248 NT NT NT
!
Upper limit
1 1 1 1 1 1 1 9 19 1 25 30 66 64 NT NT 26
Lower limit
1.0% Loading
b
ND ND ND 1 ND ND 116 ND 7 8 ND 21 21 23 72 NT ND 21
t 1/2 (days)
ND ND ND 1 ND ND 75 ND 2 2 ND 14 19 18 43 NT ND 14
Lower limit
3.0% Loading
Table VI. Half Lives and 95% Confidence Limits of PAHs and PCP i n Grenada S o i l Loaded with Site Sludges at 0.33, 1.0, and 3.0% by S o i l Dry Weight
ND ND ND 1 ND ND 248 ND NT NT ND 42 24 31 72 NT ND 37
Upper limit
OS
b
NT = no transformation observed. ND = not detected.
a
1 1 1 1 3 6 6 6 7 9 10 53 30 NT 5 ND ND NT
1 1 1 1 1 2 2 2 3 3 3 20 3 7 2 ND ND 32
1 1 1 1 5 3 3 3 4 4 4 29 6 43 3 ND ND 116
b
Upper limit
Lower limit
t 1/2 (days)
0.33% Loading Lower limit
3 3 2 2 2 5 24 22 2 NT NT 30 NT 99 NT NT 1 29
t 1/2 (days)
6 6 3 3 3 41 58 58 58 NT NT 58 NT 693 NT NT I 91
1.0% Loading
3 3 4 1 1 17 28 23 20 50 53 46 347 139 7 4 ND 105
NT NT 6 6 6 NT NT NT NT NT NT 693 NT NT NT NT 1 NT
a
t 1/2 (days)
Upper limit
Upper limit
8 8 22 1 1 32 99 53 43 139 116 NT NT NT NT 173 ND NT
Lower limit
2 2 2 1 1 12 16 14 13 30 35 22 99 63 99 2 ND 35
3.0% Loading
Half Lives and 95% Confidence Limits of PAHs and PCP i n Wiggins S o i l Loaded with Site Sludges at 0.33, 1.0, and 3.0% by S o i l Dry Weight
Naphthalene 2-Methylnaphthalene 1-Methylnaphthalene Biphenyl Acenaphthylene Acenaphthene Dibenzofuran Fluorene Phenanthrene Anthracene Carbazole Fluoranthene Pyrene 1,2 Benzanthracene Chrysene Benzo-a-pyrene Benzo-ghi-perylene Pentachlorophenol
Compounds
Table VII.
264
EMERGING TECHNOLOGIES IN HAZARDOUS WASTE MANAGEMENT
Acenaphthylene and acenaphthene, d i f f e r i n g only i n the presence or absence of a double bond (and two hydrogens), show the effect of small changes i n structure. Acenaphthene had much longer average half l i f e than acenaphthylene. Apparently, the double bond i s easier to attack, although the single bond i n acenaphthene also lowers the vapor pressure, which may affect the apparent half l i f e by v o l a t i l i z a t i o n . PCP transformation occurred i n a l l the s o i l s but was slow i n Columbus s o i l (Table V), which was from a s i t e not exposed to PCP treatment wastes. Grenada s o i l (Table VI) transformed PCP with half l i v e s ranging from one to two months, a very p r a c t i c a l range for land treatment operations. Meridian s o i l (Table VIII) also exhibited rapid transformation rates except at the highest loading rate. Wiggins s o i l (Table VII) transformed PCP with half l i v e s of three to four months, s t i l l an appropriate range for land treatment operations since Wiggins i s located i n the deep south where s o i l temperatures are high enough for e f f e c t i v e microbiological a c t i v i t y most of the year. Although the Columbus s o i l did exhibit some transformation of PCP, the low rates indicate that land treating PCP at that location would probably be i m p r a c t i c a l . The different loading rates did not markedly affect the apparent half l i v e s of the sludge constituents except i n the Columbus s o i l . A l l the loading rates used i n this study were at concentrations that previous f i e l d experience indicated would not i n h i b i t transformation. However, the 3.0% loading i n the Columbus s o i l gave the highest concentration of PAH's i n s o i l of a l l the sites i n the study, since the Columbus sludge contained the highest concentration of PAH's. This may account for the longer half l i v e s in the 3.0% loading i n the Columbus s o i l . Migration Studies. No PAHs and PCP were found above background levels (from control cores) i n the drainage water from the tested s o i l cores. Furthermore, there were no detectable increases i n PAHs or PCP i n s o i l below the zone of incorporation i n the loaded cores. This i s not unexpected, since the s o i l organic matter (from added chicken manure) and clay t i g h t l y binds these compounds. At the low concentrations of PAHs and PCP for which landfarming appears suitable (up to 30,000 ppm PAHs, 3,000 ppm PCP) migration would be very slow i n most s o i l s with high organic matter and clay. In most cases, transformation would have ample time to take place before migration would present problems. General Discussion The results of these experiments indicate that PAHs and PCP can be transformed i n s o i l at rates p r a c t i c a l for land treatment. Although the v a r i a b i l i t y of the data i s r e l a t i v e l y large i n some cases, the general trend i s clear. Based on the t r e a t a b i l i t y data from the s o i l s tested to date, land treatment of creosote and PCP wood treating wastes appears to provide a viable management alternative for s i t e remediation. The data v a r i a b i l i t y does indicate the need for conducting s i t e - s p e c i f i c t r e a t a b i l i t y studies to discern the appropriate operation and management scenario for a given s i t e .
1 1 1 1 1 1 1 1 2 2 ND 19 32 58 NT ND ND 34
Lower limit
b
NT = no transformation observed. ND = not detected.
a
ND 41 53 139 NT ND ND 43
b
1 1 1 4 1 1 1 1 5 4
t 1/2 (days)
1 1 1 NT NT 1 1 1 NT NT ND NT 205 NT NT ND ND 60
Upper limit
0.33% Loading
6 7 8 8 8 7 6 7 38 28 7 ΝΓ NT 15 16 NT NT 72
t 1/2 (days)
2 3 3 27 3 25 2 2 16 4 3 NT NT 5 5 NT NT 30
Lower limit
NT NT NT NT NT NT NT NT NT NT NT NT NT NT NT NT NT 462
a
Upper limit
1.0% Loading
1 1 1 1 1 6 10 8 8 6 1 90 NT 12 11 NT ND NT
t 1/2 (days)
Upper limit
1 1 1 I 1 NT NT NT NT NT 1 NT NT NT NT NT ND NT
Lower limit
1 1 1 1 1 3 3 3 3 3 1 37 NT 3 3 NT ND NT
3.0% Loading
Half Lives and 95% Confidence Limits of PAHs and PCP i n Meridian S o i l Loaded with Site Sludges at 0.33, 1.0, and 3.0% by S o i l Dry Weight
Naphthalene 2-Methylnaphthalene 1-Methylnaphthalene Biphenyl Acenaphthylene Acenaphthene Dibenzofuran Fluorene Phenanthrene Anthracene Carbazole Fluoranthene Pyrene 1,2 Benzanthracene Chrysene Benzo-a-pyrene Benzo-ghi-perylene Pentachlorophenol
Compounds
Table VIII.
266
EMERGING TECHNOLOGIES IN HAZARDOUS WASTE MANAGEMENT
Further study of treatment of PCP and the higher molecular weight PAHs is needed to determine the most advantageous environmental conditions and management techniques for more rapid transformation of these compounds. Many of these compounds were readily transformed in some cases. Therefore, further study may reveal reliable techniques for enhancing land treatment as a practically useful management alternative for these recalcitrant compounds. Since the environmental problems that the wood treating industry faces are almost unlimited and since the resources available to solve these problems are quite limited, land treatment is very attractive as a safe and economical solution. Literature Cited 1. Soil Survey Manual. Agric. Handbook No. 18, USDA. U.S. Govt. Printing Office, Washington, DC. 1951. 2. Test Methods for Evaluating Solid Waste. 1B. SW-846. Third Edition. U.S. EPA. 1986. 3. Cerniglia, C. E. 1984. In: Adv. in Appl. Microbiol., A.I. Laskin, Ed. Vol. 30, Academic Press, New York, NY. Vol. 30, pp. 30-71. 4. Bulman, T. L., S. Lesage, P. J. A. Fowles, and M. D. Webber. The Persistence of Polynuclear Aromatic Hydrocarbons in Soil. PACE Report No. 85-2, Petroleum Assoc. for Conservation of the Canadian Environ., Ottawa, Ontario. 1985. 5. Means, J. C., G. S. Wood, J. J. Hassett, and W. L. Banwart. Environ. Sci. Technol. 1979. 14:1524-1528. 6. Crosby, D. G. 1981. Pure Appl. Chem. 53:1052-1080. 1981. RECEIVED November 10, 1989
