FIELD EVALUATION OF
PACKED COLUMN AIR STRIPPING
PENSACOLA, FL
November 18, 1986
Compound:
Tetrachloroethylene
by
Michael D. Cummins
January 1987
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Drinking Water
Technical Support Division
Cincinnati, Ohio 45268

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TABLE OF CONTENTS
Page
1
1
1
2
3
4
5
6
6
8
List of Tables:
1	Field Operating Data
2	Tetrachloroethylene Data Set
3	Data Analysis Results
4	Cost Estimate for 98.5% Removal System
5	"	••	•• 99.9% ••	"
List of Figures:
1	Packed Column Air Stripping Process
2	EPA Pilot System
3	Concentration Profiles
4	System Configuration
References:
Table of Contents
Introduction
Packed Column Air Stripping Process
Mass Transfer Theory
Pilot System
Quality Control
Field Evaluation
Data Analysis
Equipment Size
Cost Estimate

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Field Evaluation - Pensacola, FL
Tetrachloroethylene
Introduction:
On November 18, 1986, the Technical Support Division (TSD),
Office of Drinking Water, EPA conducted a field evaluation of the
removal of tetrachloroethylene from contaminated ground water via
packed column air stripping. The field evaluation was conducted at
municipal well #8 in Pensacola, FL, which was contaminated with 150
to 250 ug L'1 of tetrachloroethylene.
The field evaluation was requested by the State of Florida,
Department of Environmental Regulation (DER). The objective of the
field evaluation was to determine the feasibility of producing
water containing tetrachloroethylene at 3 ug L*1 or less from ground
water contaminated at levels of 150 ug L*1 (98.5% removal) and 3000
ug L"1 (99.9% removal), and to estimate the equipment sizes and
costs necessary to achieve these objectives.
The TSD has developed a mathematical model to aid in
evaluating removal of volatile organic compounds via packed column
air stripping. The model has been verified using field evaluations
in the States of Wisconsin, Pennsylvania, New York, Massachusetts,
Missouri, Minnesota, New Jersey, Virginia, Louisiana, and Florida.
Prior to this report, tetrachloroethylene had been evaluated in the
first 6 states at ground water temperatures ranging from 9 to 16
deg C. The TSD's objective for the Pensacola field evaluation was
to verify the model's prediction of tetrachloroethylene removal at
24 deg C. The results of the field evaluation are summarized in
this report.
Packed Column Air Stripping Process:
If water contaminated with volatile organic compounds (VOCs)
is brought in contact with uncontaminated air, some of the VOC
molecules will transfer to the air. In the packed column air
stripping process, this transfer is facilitated as air and water
are continuously replenished and mixed together in a countercurrent
flow pattern (see Figure 1).
(1)	Contaminated water is pumped to the top of a column,
distributed at the top, and cascades down through a bed of
packing material.
.. ^
(2)	Uncontaminated air is blown in at the bottom of the column and
forced up through the same bed of packing material.
(3)	Packing material provides a combination of a large surface
area to provide mixing of air and water, contact time for

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VOC molecules to transfer from water to air, and a large
void volume to minimize energy loss of the air system.
(4)	As contaminated water cascades down through the column VOC
molecules are transferred to the air.
(5)	Air and VOCs are released to the atmosphere at the top of the
column. The concentration of VOC in air released at the
top of the column is less than the original concentration of
VOC in water due to the large air to water volume ratio. The
concentration of VOCs in air is further reduced by dispersion
into the atmosphere.
(6)	The countercurrent flow process provides contact of the most
contaminated air and water at the top of the column and the
cleanest air and water at the bottom of the column,
maximizing efficiency.
Mass Transfer Theory:
The theory of mass transfer in a packed column has been well
developed in the chemical engineering literature (Ref 1). From
mass transfer theory, the author developed Equation 1 which can be
used to predict the liquid phase concentration at any point along
the packing height. In this field evaluation thirty (30) VOC
concentrations were measured at five (5) vertical locations and six
(6) air loadings. Equation 1 was fitted to the field data by
adjusting the top of packing concentration (Xt), mass transfer
coefficient (Kla), and Henry's coefficient (H) such that the
deviation between Eq. 1 and the field data was minimized. There
are a total of nine (9) terms in Equation 1 required to predict the
liquid phase concentration (X).
Concentration Profile with Unstrippable Fraction:
X = Xt * ( Fu * (1-C) + C ) 			
Eq. 1	Where :
C-( (R*B)-1)/ ( (R*A) -1)
A = EXP(( Zb ) * (Kla/L) * ((R-l)/R) )
B - EXP((Zb-Z) * (Kla/L) * ((R-l)/R) )
R=(G/L)*(H/Pt)
Xt: VOC concentration at top of packing (ug L"1). The
concentration at the top of the packing material (Xt) is
approximately the raw water concentration; however, there
may be some VOC loss as water travels through the well
pump, the piping between the well and the air stripping
system, and the liquid distribution system at the top of
the packed column. This VOC loss is collectively
referred to as the influent end effect. In this field
evaluation Xt was determined by regression analysis. It

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was not necessary to evaluate the raw water concentration
or the influent end effect.
Fu: VOC unstrippable fraction (fraction of Xt). The
unstrippable fraction (Fu) is used to account for
anomalies that are observed in real systems. The
unstrippable fraction may be due to short circuiting of
water through the packed column, background VOC
contamination in the influent air, a physical or chemical
complex holding the VOC in the liquid phase, cross
contamination between sample bottles, or other unknown
phenomenon. In general the unstrippable fraction is a
fraction of Xt that, for some reason or another, cannot
be removed by the air stripping process at even the
highest air to water ratios or the tallest packing
heights. In this field evaluation no unstrippable
fraction was observed. Thus, Fu was set to 0.
G: Air loading (m3 m"2 sec"1). The air loading term (G) is
the total air flow through the column per unit of cross-
sectional area of the column.
L: Liquid loading (m3 m"2 sec'1). The liquid loading term (L)
is the total liquid flow through the column per unit of
cross-sectional area of the column.
H: Henry's coefficient (atm m3 water m'3 air). Henry's
coefficient (H) is a physical-chemical property that
expresses the volatility of 'the particular VOC. Henry's
coefficient is dependent only on the temperature and
molecular properties of the VOC and not dependent on the
other eight (8) terms in Equation 1. In this field
evaluation Henry's coefficient for tetrachloroethylene
was determined by regression analysis.
Pt: Operating pressure (atm). The operating pressure (Pt) is
generally 1 atmosphere.
Zb: Packing height (m). The term Zb is the total height of
the packing material.
Z: Vertical location within column (m). The term Z is the
vertical location within the column measured from the top
of the packing material.
Kla: Mass transfer coefficient (sec'1). The mass transfer
coefficient (Kla) expresses the overall rate of VOC
transfer from the liquid phase to the air phase. The
mass transfer coefficient is dependent on the VOC
molecular properties, packing material properties, liquid
loading, and air loading. The mass transfer coefficient
is not dependent on the concentration terms Xt and Fu or
the packing height terms Zb and Z. In this field

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evaluation the mass transfer coefficient was determined
by regression analysis.
X: Predicted VOC concentration (ug L"1). The predicted VOC
concentration at location Z is a function of the other
nine parameters.
Pilot System:
The pilot system, shown in Figure 2, consists of a 24 ft tall,
2 ft diameter aluminum column packed with 18 ft of 1 inch plastic
saddles. The pilot system was constructed in 3 ft tall sections to
facilitate transportation to the field.
At Pensacola a 2 inch fire hose was used to connect well #8 to
the influent line of the pilot system. Mounted on the influent
line of the pilot system was a control valve, orifice plate, and
mercury manometer to control and monitor the liquid flow. Water
was pumped through the liquid flow control system to the top of the
pilot system where four upturned 2 inch elbows distributed the
liquid onto the packing material. Water cascaded down through the
packing material and was collected in an effluent tank at the
bottom of the column. A 4 inch fire hose was used to discharge the
effluent water to a storm sewer.
Influent air was drawn into the system at the bottom of the
column, passed up through the packing material to the top, and
returned to ground level through a 6 inch air duct. Mounted inside
the air duct was a pitot tube, an orifice plate, and a control
damper to monitor and control the air flow. Following the control
damper the air duct was connected to the intake side of a blower.
Air was discharged at ground level 30 ft downwind from the air
intake. Water manometers were installed above the top of packing
material and near the pitot tube to measure air pressure.
Eighteen sample ports were installed at 1 ft intervals along
the column height to sample liquid from the center 1 ft of the
column. The sample ports were designed such that air was not
withdrawn with the sample. This sampling system permitted
monitoring the concentration profile of VOCs predicted by Eq. 1
along the column height. Five sample ports, selected at 3 ft
intervals, were used in this evaluation. The pilot system was
operated at steady state for 30 minutes before samples were
collected.
Quality Control:
Prior to conducting the field evaluation at Pensacola, a
contract was established with Southwest Research Institute (SwRI),
San Antonio, Texas, for the bulk of the sample analyses. Resources
were also reserved at the EPA, TSD laboratory in Cincinnati, OH,
for analysis of duplicate samples. Laboratory sample numbers were
assigned to field run numbers/sample port locations. The

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laboratory sample numbers were used by the laboratories and the run
numbers /sample port locations were used by the field crew.
Information on the sample labels included the sampling date, city
name, preservative used, project officer's name, and laboratory
that would receive the sample bottle. All of the labels were
prepared by a computer plotter using waterproof ink. All sample
bottles were spiked with mercuric chloride as a preservative.
The operation and sampling of the packed column air stripping
system were conducted by the EPA project engineer and EPA equipment
mechanic who together designed and constructed the pilot system.
All samples were collected by only one individual. At the end of
the field operation all samples to be sent to SwRI laboratory were
repacked in shipping containers, preserved with ice, and sent via
overnight Federal Express delivery. Samples were analyzed within
three weeks using EPA Method 501.2, liquid-liquid extraction with
electron capture detector.
Twelve (12) bottles were filled with laboratory organics-free
water, labeled "Blank", and packed with the sample bottles so that
cross contamination between sample bottles could be evaluated. Six
(6) blank samples were analyzed by SwRI for tetrachloroethylene and
none indicated tetrachloroethylene. Thus cross contamination was
not observed.
Six samples were collected for blind duplicate analysis to
evaluate the relative standard error associated with sampling,
shipping, and analysis. These samples were given a fictitious
sample port location, packed with the other samples, and sent to
SwRI for analysis. SwRI analyzed all of the blind duplicate
samples. The relative standard error was 18% which is considered
to be acceptable for EPA Method 501.2.
A different set of six duplicate samples were collected to
evaluate the accuracy of the laboratory analysis. This set of
duplicate samples were sent to TSD for analysis and the original
samples sent to SwRI for analysis. All pairs of duplicate samples
were analyzed. The percent difference between the TSD analysis and
the SwRI analysis indicated that on the average the SwRI analysis
were lower than the TSD analysis by 15%. This indicates that the
tetrachloroethylene concentration may be higher than reported by
SwRI. However, this does not impact the removal efficiency
observed in the pilot system.
A total of forty-two (42) samples were sent to SwRI for
analysis. All were successfully analyzed.
Field Evaluation:
The liquid and air loadings for the Pensacola field evaluation
were selected using the results from prior field evaluations.
Based on prior field evaluations and the physical/chemical
properties of tetrachloroethylene, the Henry's coefficient in this

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situation should be in the range 0.3 to 0.6 atm m3 water m"3 air.
Using the lower value as an estimate for Henry's coefficient and
the Onda correlation (Ref 2) to predict the mass transfer
coefficient, the model indicated that 99% tetrachloroethylene
removal should be achieved using a liquid loading of 0.020 m3 m'2
sec"1 (30 gpm ft'2), an air to water ratio of 18 to 1, and a packing
height of 5.3 m (17.5 ft). This liquid loading and six air to
water ratios were selected for evaluation. The air to water ratio
for the first run was selected so a high removal efficiency would
be
obtained. The air to water ratios for the sequential runs were
stepwise reduced such that the air flow in the sixth run would
result in low removal efficiency. The air to water ratios were
35:1, 18:1, 10:1, 5:1, 2.5:1, and 1.5:1, respectively. The field
operating data are shown in Table 1.
The concentration data for tetrachloroethylene are shown in
Table 2. The first sample port is located 0.15 m (0.5 ft) from the
top of the packing material. The sample ports are located at about
3 ft intervals along the column height with the last sample port
(5.34 m) located 0.15 m (0.5 ft) from the the bottom of the
packing. The tetrachloroethylene concentration decreased as water
passed through the column (Table 2 and Figure 3).
Data Analysis:
The top of packing concentration (Xt), mass transfer
coefficient (Kla), and Henry's coefficient (H) were determined by
adjusting their values such that the deviations between Eq 1 and
the concentration data were minimized. The solid lines in Figure
3 are the best fit concentration profiles. The overall relative
standard error between the best fit concentration profiles and the
data was 19% which was within the range of the relative standard
error associated with sampling, shipping, and laboratory analysis.
A relative standard error of 19% represents a good fit between a
math model and data as observed in Figure 3.
The results of the data analysis are presented in Table 3.
The best fit value for Xt, Kla, and H are 146 ug L'1, 0.0185 sec'1,
and 0.39 atm m3 water m"3 air. respectively. The 95% confidence
intervals are 133 to 160 ug L , 0.0172 to 0.0196 sec'1, and 0.32 to
0.46 atm m3 water m*3 air respectively. These confidence intervals
represent tolerances of +/- 9.2, 6.5, and 18 percent of the
respective best fit values.
The best fit removal efficiencies are 99.15%, 98.9%, 98.3%
95.6%, 82%, and 58% for the six air to water ratios, respectively.
The best fit effluent tetrachloroethylene concentrations from the
first three runs were 1.2, 1.7, and 2.5 ug L'1, respectively. Thus,
the pilot air stripping system did reduce tetrachloroethylene to
less than 3 ug L'1 in the first three runs.

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The Onda correlation (Ref 2), in general, provides a
reasonable estimation of the mass transfer coefficient. The Kla
values predicted for runs 1 through 6 by the Onda correlation using
the best fit Henry's coefficient are 0.0235, 0.0230, 0.0225,
0.0215, 0.0200, and 0.0186 sec"1, respectively. The Kla value
measured in the field evaluation was 16% lower than the average Kla
value predicted by the Onda correlation. Thus, the packing height
necessary to achieve a treatment objective will be sightly greater
than determined in the preliminary analysis using the Onda
correlation.
Equipment Size:
The result of the field evaluation/data analysis can be used
to size a packed column air stripping system.
Applying safety factors to uncertain parameters such as the
mass transfer coefficient and Henry's coefficient is prudent
engineering practice. In general, the lower 95% confidence limit
offers a reasonable safety margin; however, other confidence limits
may be preferred depending on the application. The lower 95%
confidence limits for the mass transfer coefficient and Henry's
coefficient are 0.0172 sec'1 and 0.32 atm m3 m'3, respectively.
Applying safety factors to both the mass transfer coefficient and
Henry's coefficient will increase the confidence above 95%.
Equation 1 can be manipulated to obtain the packing height
necessary to achieve a desired effluent concentration. The result
is Equation 2.
Packing height Equation:



(Xt-Xu)






	 * (R—l) + 1


7h s
" L R
* In

(Xb-Xu)







Kla (R-i;
_

R

Where:
Zb = Packing height (m)
Xb = VOC Concentration at bottom of packing (ug L"1)
Xu = Unstrippable concentration (ug L'1) (Assumed to be
zero)	Other terms are defined in Eq 1
, The design requirement at Pensacola is to reduce 200 ug L'1
tetrachloroethylene to 3 ug L'1 in well #8 which has a design flow
of 0.13 m3 sec'1 (2000 gpm). Using the liquid and air loadings from
run number 2, 0.020 m3 sec'1 (30 gpm ft'2) and 18 to l, respectively,
the required packing height will be 5.7 m (18.7 ft), the column
diameter will be 2.9 m (9.5 ft), the air flow will be 2.3 m3 sec'1
(4900 SCFM), and the air pressure drop through the column will be

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180 N m"2 (0.7 inch water column) . The equipment configuration is
presented in Figure 4.
It should be noted that the safety factors increase the system
size thus the most probable effluent concentration will be lower
than 3 ug L"1. The most probable effluent concentration is computed,
using the best fit Kla and H (0.0185 sec'1 and 0.39 atm m3 m'3
respectively) and Eg. 1, to be 1.9 ug L'1, a reasonable margin of
safety.
If the design influent concentration were increased to 3000 ug
L'1 then the required removal efficiency will be increased to 99.9%,
the packing height will be increased to 9.5 m (31 ft), and the air
pressure drop will be increased to 300 N m'2 (1.2 inch water
column). The column diameter and air flow will remain the same.
The most probable effluent concentration will be 1.4 ug L"1.
Cost Estimate:
The estimated capital and operating costs of the 98.5% removal
system are $270,000 and $21,000 per year, respectively, whereas the
estimated capital and operating costs of the 99.9% removal system
are $340,000 and $27,000 per year, respectively. The cost
estimates for the two systems are shown in Table 4 and 5,
respectively.
The process equipment shown in Table 4 and 5 include the
column shell, column internals (i.e., liquid distributor, liquid
redistributor, and packing material support plate), packing
material, one blower, and one pump. The cost estimate for the
process equipment is based on vendor quotes of the individual items
and includes delivery to the site but does not include assembly or
installation. The cost estimates for the column shell and
internals are based on 304 stainless steel (SS); however, other
materials of construction are also available and may reduce or
increase the cost.
The support equipment includes assembly and installation of
the above process equipment, a 4.2 by 4.2 by 4.0 m (14 x 14 x 13
ft) concrete air well which is a foundation for the packed column
and a 70 m3 (18,000 gallon) liquid reservoir, 60 m (200 ft) of
piping, instrumentation, air duct, and electrical connections. The
electrical connection cost estimate is based on 25% of the blower
and pump capital cost. The other support equipment cost estimates
are based on material quantities. The support equipment cost
estimate should provide a reasonable estimate of cost for these
items; however, these items will vary from site to site and should
be reviewed by a design engineer familiar with the Pensacola site.
The total direct cost includes all equipment installed at the
site and is the sum of the process and support equipment.

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The indirect cost includes all non-physical items required for
the air stripping system. This includes sitework, design
engineering, contractor overhead and profit, legal and financal,
interest during construction, and contingencies. The cost estimate
for each of these items is based on percentage of the total direct
cost. The precentages were selected by a committee of engineers
such that the Office of Drinking Water's cost estimating procedures
for various water treatment technologies can be based on the same
assumptions. The percentages are 15, 15, 12, 2.5, 6, and 15%,
respectively. The actual percentages will be site specific and
should be reviewed by an engineer familiar with the Pensacola site.
The total capital cost is the sum of the direct and indirect
costs. The amortized cost is the total capital cost amortized over
a 20-year time period at 10% interest rate.
The operating cost is intended to reflect the additional cost
of the air stripping system and does not include existing operating
costs. The operating cost is based on the projected volume of
water treated per year, the electrical power consumed by the air
stripping system, and the maintenance of the mechanical and non-
mechanical process equipment. The electrical power for the blower
was estimated based on the air flow, air pressure drop through the
column plus 500 N m"2 (2 inch water column) of pipe friction, 50%
fan efficiency, 70% motor efficiency, and 25% motor size-up. The
electrical power for the pump was estimated based on the liquid
flow, liquid head loss from the top of the packing material to the
bottom of the air well plus 12 ft of pipe friction, 80% pump
efficiency, 80% motor efficiency, and 25% motor size-up. The
electrical power rate was assumed to be 10 cents per Kw Hr and the
volume of water treated per year assumed to be 50% of the design
flow.
The maintenance cost is based on 10% and 4% of the mechanical
and non-mechanical process equipment cost, respectively. The labor
operating cost is based on a flat rate of $0.0008 per m3 (0.3 cent
per 1000 gallon) treated and the volume of liquid treated per year.
The administrative cost is based on 20% and 25% of the labor and
maintenance cost, respectively.
The total annual cost is the sum of the amortized capital and
operating cost. Finally, the total production cost is the total
annual cost divided by the volume of water treated per year.
The cost model was developed to give a general indication of
the economics of the packed column air stripping process. These
costs are presented only to evaluate the economic feasibility of
using a packed column air stripping system to remove
tetrachloroethylene from ground water. The specific site
requirements at Pensacola, FL, will differ from the assumptions of
the general cost model. The use of a large scale, on-site pilot
system lends confidence in the accuracy of equipment size necessary
to obtain tetrachloroethylene removal; however, it is emphasized

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that these costs should be reviewed by an engineer familiar with
the Pensacola site.
This field evaluation was conducted using 1 inch plastic
saddles as packing material. The 1 inch plastic saddle packing
material was selected due to availability from a number of
suppliers and the existence of packing characteristics in the
technical literature. Other packing materials are also available;
however, the removal efficiencies will differ from the packing
material used in this field evaluation.
The fate of volatile organic compounds (VOCs) when discharged
into the atmosphere is uncertain. The compounds will disperse in
the wind currents and may break down when exposed to sunlight. In
most cases the impact of VOC discharge to the atmosphere from a
packed column treating contaminated drinking water will be minimal.
The information contained in this report should not be
interpreted as requirements or recommendations from EPA. The field
evaluation, laboratory analysis, data analysis, and calculations
are believed to be correct; however, neither the author nor EPA can
be responsible for any errors resulting directly or indirectly from
the use of the information contained in this report.
The author expresses special thanks to Robert Kneipp, Ken
Evans, Mary Ann Feige, and SwRI analytical laboratory. Without
their professional assistance in setting up and operating the pilot
system and analyzing the resulting samples this field evaluation
could not have been accomplished.
REFERENCES
1.	Treybal R. E., Mass-Transfer Operations, 3rd Ed., McGraw Hill
(1980).
2.	Perry, R. H. and C. H. Chilton, Chemical Engineers' Handbook,
5th Ed., McGraw Hill (1973).

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Table 1
Field Evaluation - Tetrachloroethylene
Operation Data
Packing Height = 5.5 (m)
Temperature = 24.0 (Deg C)
Liquid Loading - 0.020 (in3 m"2 sec'1)
Run Air	Air	Air Pressure
Water	Loading	Drop Gradient
Ratio	(m3 m'2 sec'1)	(N m*2 m'1)
1	35.	0.70	140.
2	18.	0.35	32.
3	10.	0.20	14.
4	5.0	0.10	4.6
5	2.5	0.050	2.3
6	1.5	0.030	*
* Below limit of measuring device.
Table 2
Sample
Port
Location
Concentration Profile Data Set
Tetrachloroethylene
Concentration (ug L"1)
Run
(ro)
1
2
3
4
5

0.15
130.
120.
120.
130.
150.
160
1.68
38.
39.
47.
62.
100.
150
2.90
12.
17.
20.
43.
81.
120
4.12
3.6
6.9
12.
22.
59.
120
5.34
0.88
1.8
2.9
7.6
22.
55

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Table 3
Data Analysis Results
Pensacola, F1
Compound :	Tetrachloroethylene
Ground Water Temperature :	24 (Deg C)
Number of Samples :	30
Relative Standard Error :	19%
Best Fit	95% Confidence
Interval
Xt	(ug L"1) 146	133 to 160
Kla	(sec1) 0.0185	0.0172 to 0.0196
Henry (atm m3 m'3) 0.39	0.32 to 0.46
Air to Water Ratio 35 18 10	5 2.5
1.5 Best fit Effluent (ug L'1) 1.2 1.7 2.5	6.4 26.
62. Best fit Removal (%) 99.15 98.9	98.3 95.6
82. 58.
Kla predicted by Onda 0.0235 0.0230 0.0225	0.0215 0.0200
0.0186

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Table 4
98.5% Removal System Cost Study Estimate
Interest Rate= 10.	% per year
Power Cost= 10.	c KW*1 hr*1
Financing Period= 20.	Year
Use Rate= 50.	% Design Flow
Construction Cost Index= 405.00
Process Equipment:	Capital Cost (K$)
304 SS Column Shells	13.8
Column Internals	13.1
Packing	18.7 t
Blower	2.7
Pumps	12.1
Total Process Equipment	60.3
Support Equipment:
Installation	32.5
Air Well	35.3
Piping	24.8
Instrumentation	5.1
Air Duct	0.5
Electrical	3.7
Total Support Equipment	101.9
Total Direct Cost	162.2
Indirect Cost:
Sitework	24.3
Engineering	24.3
Contractor	19.5
Legal & Financial	4.1
Int. During Const.	9.7
Contingencies	24.3
Total Indirect Cost
Total Capital Cost
Amortized Capital Cost
Operating Cost:
Liquid Pumping
Blower
Labor
Maintenance
Adminstrative
Total Operating Cost	21.3
14.2
0.6
1.9
3.3
1.2
106.2
268.4 K$
31.5 (K$ per Year)
Total Annual Cost
Total Production Cost
treated

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Table 5
99.9% Removal System Cost Study Estimate
Interest Rate= 10.	% per year
Power Cost= 10.	c KW"1 hr"1
Financing Period= 20.	Year
Use Rate= 50.	% Design Flow
Construction Cost Index= 405.00
Process Equipment:	Capital Cost (K$)
304 SS Column Shells	21.1
Column Internals	19.4
Packing	30.6
Blower	2.7
Pumps	12.1
Total Process Equipment	86.0
Support Equipment:
Installation	49.7
Air Well	35.3
Piping	26.1
Instrumentation	5.1
Air Duct	0.5
Electrical	3.7
Total Support Equipment	120.5
Total Direct Cost	206.4
Indirect Cost:
Sitework	31.0
Engineering	31.0
Contractor	24.8
Legal & Financial	5.2
Int. During Const.	12.4
-Contingencies	31.0
Total Indirect Cost	135.2
Total Capital Cost	341.7 K$
Amortized Calital Cost	40.1 (K$ per Year)
Operating Cost:
Liquid Pumping	18.4
Blower	l.l
Labor	1.9
Maintenance	4.3
Adminstrative	1.5
Total Operating Cost	27.2
Total Annual Cost
Total Production Cost
treated
67.3 K$ per year
3.3 c per m3

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Figure 1
Packed Column Air Stripping Process
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(6) VOC
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(4) VOC Transfer

(2) Air Flow
(6) 9 9.0% Removal Possible

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Figure 2
Packed Column Aii Strip.pina Pilot System
Influent Watar
from
Wall Pvmp
Efflaant Watar
to Drain

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Figure 4
——WmB—
Cost Model Configuration
Column Dlametor
7A7
S»l»ct Fill
Not to Scale

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Figure 3
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Location (Z)
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Location (Z)

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