Remediation Journal Volume 4 issue 1 1993

8/10/2019 Remediation Journal Volume 4 issue 1 1993

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Technical and Economic

Analyses in the Development

of Bioremediation Processes

Paul R. Ammann Guyh

S. Koch

Paul Ammann i s a

principal of m e Bra &

Group, an economic,

management, and

environmental

consulting

im

n Ciambridge,

Massacbusetts. He bas

more tban tbirty years'

experience

in

tbe

developmat, costs, and

applications of

environmental,

cbemicd

and metallurgical

tecbtwhgies. He fcwluses

one n dm e n t a l

consulting

in

tbe areas

of

CERCLA

cost recovery,

evaluatiolS

R&D

planning, and tecbnical

and market feasibility

analysis. Gayle

S.

Kocb

i s

a principal of Tbe Bra &

Croup. Sbe bas

evaluated environmental

liabilities in connection

witb settlements,

Utigatioff, nsurance

recovery,

acquisitions

and

sales

and strategic

planning.

environmental

uabiuty

Ihe ve latge extent

of

subsugace and groundwater contamination

with toxic otganic compounds has prompted research on a number of

bioremedialprocesses. Ihejustification

of

this research has been to achieve

lower overall remedial costs than are incurred by currently existing

technologies. Laborato studies are often undertaken with the notion that

a new set ofprocess conditions can reduce reagent consumption or the time

for treatment

by

a signijkant actor with an attendant reduction in overall

remediation costs. Research programs are initiated on the basis

of

these

simple premises. Our work has shown that many research projects have

been undertakenfor the wrong reasons and that eqerimental effort has

ojen not been directed toward latge-scale implementation.

A preliminaryprocess analysis has been shown to be a very valuable

componentofany research and developmentprogramon bioremedial and

other innovative technologies.As described in this article, the analysis 1 )

identipes the critical engineering and cost parameters and (2) provides

guidance to the research program in the design

of

eqeriments and the

collection

of

data. 7he methodology is also useful in the

review

ofproposed

new technologies and treatment equipment. 7he article includes an

exampleof a process analysis

for

an actual development project directed

toward the remediationofsolids contaminated with chlorinated hydrocar-

bons to illustrate the benefits and the power of the technique.

Bioremediation processes offer potential for lower-cost remediation of

soils, sludges, and sediments and surface and subsurface water contami-

nated with organic compounds than other physical, chemical, or thermal

processes. Consequently, large efforts are being directed to research and

develop bioremedial processes. Because

of

the large costs

of

R&D

programs, of developing and proving new technologies, and the improve-

ments in and the competition of existing remedial processes, it is prudent

to focus studies toward realistic commercial remedial opportunities.

This article describes an approach for the evaluation

of

applications

of

research results

to

full-scale remediation. The discussion addresses the

treatment of soils, sludges, and sediments, but the methodology is also

applicable to water treatment processes.

REMBDIATION/WINTER993/94 115


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PAULR AMMA GAYLE.KOCH

AB he requirements

of

even higher

etandi,wda

of

ckanup

ore

being applied

throughout the

country, the need for

lower cost

olutions is

becoming even more

important.

OPPORTUNXTIWNEEDS

Organic contamination is present in soils, sludges, and even in

sediments

of

rivers and streams. The types

of

contaminants vary from

volatile solvents to less volatile compounds such as polyaromatic hydro-

carbons (PAHs) and polychlorinated biphenyls (PCBs). Contaminants

occur as small hot

spots,

as well as large areas with a number

of

compounds

distributed throughout the area.

Organic contamination h s also migrated from disposal areas into

surface waters and groundwater. Through groundwater movement, sub-

surface plumes of organic compounds exist at many locations throughout

the world.

A

wide variety

of

remediation processes

exists

for the treatmentof soils,

including physical (e.g., vacuum extraction), chemical (e.g., solvent

extraction), and thermal (e.g., low temperature desorption and incinera-

tion) processes. New processes are also being developed or are evolving

from the industrial sector, as equipment used for commercial reasons is

modified

to

satisfy needs in remediation. These existing and evolving

technologies compete with bioremediation in the environmental remediation

market.

Remediation costs

for

contaminated soils and waters are generally

high. As the requirements of even higher standards of cleanup are being

applied throughout the country, the need for lower-cost solutions is

becoming even more important.

In much of the published work in the bioremediation industry, the

focus is on technical issues, such as (1) reaction mechanisms and

(2)

kinetics as a function of contaminant mix,

soil

types, and concentrations

of relevant contaminants and components. Although this type of research

is essential for the successful development of new processes, it appears

that there has been

less

attention paid

to

design concepts and the

economics of technologies that could result from the research. Early

attention

to

the technology development and costs is vital to achieve cost-

effective research programs.

BIOTREATMENT

PROCESSES

It

appears that biological treatment processes will play an important

role in the future in remediation of areas of contamination. Biological

treatment processes exhibit some intrinsic advantages compared to other

alternatives. These include:

Low

reagent costs

Typically, nutrient requirements are small and

the costs therefore tend to

be

low.

Low

energy

costs In the absence

of

a need

to

heat biological

treatment systems more than, say, 10 o 2OoC energy requirements

tend to

be

low. Most of the energy needs are for mechanical energy

to

move solids and liquids.

Low capital costs Reaction systems in which organics in solids or

liquids are mixed with organisms and nutrients are typically simple.

For example, solids treatment processes use conveyors, reagent

116

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TECHNICALND ECONOMICNAL.YSBSN THE DEVELOPMENT

F BIOREMEDIATION

ROCESSES

mix tanks, and large contactors. Consequently, the capital costs

tend to

be

small in comparison with other treatment systems such

as thermal desorption or incineration.

Environmental acceptance.Biotreatment processes operate at low

temperatures, and gas flows, such as air for oxidative treatment, are

small. Any air emissions

of

concern can

be

controlled at very

modest cost with existing technology. Similarly, water discharge

streams can

be

treated with conventional water treatment pro-

cesses. If necessary, any stream can

be

pasteurized

to

destroy

microorganisms.

There are, however, potential major disadvantages

to

biological

treatment processes. Some of these are:

The selection o f one of

the

available

options

is

baaed

on

echnical

feasibili ty, overall

economics, and

satisfaction o f

regulatory matters

and

public concerrta.

Relatively long treatment times. In contrast to chemical, physical,

or thermal treatment processes in which reaction times typically

vary from seconds or minutes

to

less

than an hour, biological

treatment processes often require days or months. Consequently,

reactor vessels are much larger than for alternative treatment

processes, and/or cleanup times may

be

extended significantly.

Incomplete destructioddegradationof organics. Biological water

treatment systems, such as activated sludge, are very effective for

destruction

of

many organic compounds. However, biological

treatment systems may not be as effective for the destruction

of

certain toxic organic compounds, particularly in soils, sludges, and

sediments.

Dzflcult application.For many toxic organic compounds, specific

organisms are required to achieve degradation or destruction. In

some instances, indigenous microorganisms either have limited

effectiveness

or

are ineffective for reactions with toxic organic

compounds. For in-situ applications, there may be additional

complications such as preferential pathways for nutrients or

biodegradation under anaerobic conditions.

T icity. The presence of certain elements, such as heavy metals

or

compounds, may limit the effectiveness

of

microorganisms.

Primarily effectiveon otganic contaminants.Bioremediation pro-

cesses are generally iimited

to

soils and solids contaminated only

with organic compounds. If heavy metals are present, for example,

either bioremediation is only one component of remediation, or it

may not

be

cost-effective compared

to

alternatives.

SELECI'ION OF ALTERNATIVES

In planning the remediation of sites contaminated with organic

compounds, environmental managers usually have several process op-

tions available. The selection

of

one

of

the available options is based on

technical feasibility, overall economics, and satisfaction of regulatory

matters and public concerns. For biotreatment processes, some of the

decision criteria are described in the following section.

R E M E D X A T I O N ~ ~ I N T E R

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PAULR AMMA GAYLE

. KOCH

Whether a cleanup i s

carried out

by

a

remedial contractor

or by the owner of a

property, the total

cost

i s

governed

by

the initial

investment. .

Technical Feasibility

Tech nical feasibility is, of course, critical to the selection of a remedy.

It is also a k ey focus of much of the ongoing research an d development

work in bioremediation.

Effective organism.

The degradat ion

of

selected organic com-

po un ds from initial conc entrations to specified cleanu p levels must

be demonstrated in a field setting. The demonstration becomes

complicated if there are m ultiple organic compo unds or other

contaminants of conce rn (e.g., metals) present at a site.

Rates and extentof degradatioddestruction.

The rates

of biocon-

version are important to the econo mics, as described later, but it

is also important that the biological reactions redu ce the levels of

toxic organic compounds to the required cleanup levels. This

criterion is important if cleanup levels con tinue to decrea se in the

future. For example, Jerger et al. (1993) reported on the slurry

reactor treatment of soils that significantly reduce d the levels

of

creosote but did not reach the required cleanup levels.

Control

of

reaction conditions.

The microorganisms should be

consistently effective in degrading o r destroying haz ardou s organic

com poun ds, and the reactions should not be subject to poisoning

or

loss

of effectiveness during a large-scale site remediation.

Typeofequipment.Biotreatment processes are often ad vantageous

becau se they typically employ simple p rocess equipme nt, such as

tanks and solids-liquids contactors.

Economics

Overall costs play a very large role in the selection of a remediation

process. Whether a cleanup

is

carried out by a remed ial contractor

or

by

the own er of a pro perty, the total cost is gove rned by th e initial investment

for the process equipment, the direct operating costs for site cleanup, and

a financial return o n the u se of the equipment.

Studies. Significant expenses may

be

incurred for treatability

studies, pilot tests, an d other studies. Study costs are generally

higher for new, unproven technologies.

Investment.

The capital cost of the biotreatment process must

be

recovered from its operation at on e o r more sites. If a process is

dedicated to o n e site, the soil volume must be sufficiently large so

that the allocation

of

the investment

to

the

soil

treatment

is

acceptable. A lternatively, transportable equ ipm ent allows flexibil-

ity for treatment

of

larger soil volume at multiple

sites.

Because

there is a large element of uncertainty abo ut h ow many sites and

the quantity

of solids

or liquids that may

be

treated by an

equipm ent p ackag e, it is important that the cost of equipment be

kept as

low

as possible. Investment may

be

reduced by using

standard equipm ent, such as tanks a nd reactors, and establishing

proces s conditions that allow the shortest

possible

treatme nt times.

~ ~~

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TECHNICAL

ND ECONOMICNAL.YSESN THE

DEVELOPMENT

F BIOREMEDIATIONROCESSES

...here may be

concern over

introduction of

microbes into the

environment,

particularly

for

new,

genetically deeigned

organism.

Unit treatment cas

Technologies with the lowest overall treat-

ment costs that meet the cleanup requirements are sought in the

feasibility studies.

Pmject size.

Large projects can achieve economies of scale and

therefore relatively smaller unit costs.

Utilization.

Equipment costs may

be

spread over a number

of

sites.

To the extent that a transportable process

is

not used continuously,

the owner/operator must allocate fixed costs accrued during

downtime to each site.

RegulatoryIssuesand Public Acceptance

All remedial processes must have operating permits and should be

acceptable

to

local communities and neighboring residents. In contrast

to

some technologies such as incineration,

in

which stack emissions are of

concern, biotreatment processes should receive acceptance because solid

and liquid discharges from biotreatment processes should comply with all

applicable regulations. However, there may

be

concern over introduction

of microbes into the environment, particularly for new, genetically

designed organisms. Regulatory and public acceptance issues that must be

addressed include:

Permits and appmvaki. State and local permitting can be an

expensive and time-consuming process. In addition, for many

hazardous waste sites, bioremediation must

be

compared with

alternative treatment options and approved based on cost and

effectiveness criteria.

Risks to humansand environment.Studies should be conducted

to

show that the bioremedial process will reduce risks

to

humans and

the environment

to

the desired level.

Public perceptions.

Public perception

of

any risks introduced by

the bioremedial process must be addressed, often by holding

public meetings and making site documents and site experts

available

to

the public.

Many bioremediation research programs focus exclusively on techni-

cal feasibility. However, because ultimate project success will also be

strongly influenced by economics, regulatory issues, and public accep-

tance, it

is

important that significant attention

be

paid

to

these areas as well.

A L T A T I V E T R E A ~ P R 0 c E S S E S

Developers of bioremediation technologies must keep in mind that

these technologies will ultimately compete in the marketplace against

other remedial options. The options for the remediation

of

contaminated

solids and water are different.

Remediation of

Soils,

Sludges,

and

Sediments

The remediation of

soils,

sludges, and sediments can generally be

divided into two major categories: excavation with on-site or off-site

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PAULR AMMA GAYLE

.

KOCH

treatment a n d in-situ treatment.

Excavation with on-site

or

08-site treatment.

Excavation not o nly

adds

cost

to the remediation

of

a site, but it also

poses

som e risk

of

spreading contamination into

the

environment an d adds health

risks

to

the remediation workers. However, postexcavation treat-

ment

is

used extensively for the remediation

of

contaminated

solids.

Some

of

the most important processes are listed

beIow

(Lewis, 1993):

Incineration

Thermal desorption

Thermal aeration

Solids washing

Solvent extraction

Land farming

Composting

Slurry pha se bioreaction

The last three alternatives emp loy microorganism s

to

achieve degradation

or destruction

of

the organic contaminants.

In-situ treatment.

Degradation

or

destruction

of

organic com-

pounds without excavation has some advantages over the pro-

cesses described ab ove. O ne important factor

is

the savings

of

the

excavation cost, which may

be

significant, but not

as

large

a s

the

treatment

costs. In

addition, risks to humans and the environment

throug h direct contact o r inhalation of contaminants are reduced.

Some

of

the alternatives that ar e available include:

Soil vapor extraction

(SVE)

Vapor extraction with h eating o r fracturing (hardrock)

Solidification/containment

Vitrification (fusion of soils)

Infrared heating

Soil flushing (active

o r

natural)

Soil flushing with biotreatm ent

Bioventing

Remediation

of

Contaminated

Water

The remediation

of

contaminated surface and groundw ater can also

be

divided into two major categories: surface treatment an d in-situ treatment.

Surface treatm ent.

There are several options available for the

surface treatment of contam inated wa ter. Many are derivatives of

municipal wastewater treatment systems. Water treatment plants

may be comprised

of

several modules according

to

the chemical

complexity

of

the w ater. For exam ple, organic removal

or

destruc-

120 REMEDIATION/WINTER993/94


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TECHNICAL

ND ECONOMICM,YSB

IN TH

DEVBU~PMENT

F BIOREMEDIATION

ROCESSES

The olids are

excavated, screened to

remove oversize Solid8

...

and conveyed to

storage bins.

tion may be preceded by a metals removal step. Some of the

organic treatment or removal modules may be:

ChemicaVUV oxidation

Adsorptiodabsorpt ion

Biotreatment processes

Air stripping (with o r without heat)

When hazardous wastes have contributed to contamination of either

surface waters or groun dwa ters that have migrated off-site, the contami-

nated plume may be collected in wells and either treated off-site or

pumped back to the site where the contamination

is

located. Physical

barriers such as slurry walls may also

be

used to impede or prevent

contaminant migration.

In-situ treatment. In contrast to the surface treatment approaches

described abo ve, new developm ents have be en directed toward

the in-situ degradation of organic contaminants in groundwater.

There are two general approaches:

Injection of microorganisms and nutrients

Pumping groundwater, surface addition of organisms, and

reinjection (in this concep t, the aqu ifer bec om es th e reactor,

saving the costs

of

construction of reactors at th e surface)

At various stages in the bioremediation R&Dprocess, managers should

evaluate and upda te their perception

of

the com petitive positioning of their

technology versus alternative, competing technologies. Further

R&D

expenditures can then

be

focused o n areas that are likely

to

have usable,

commercially feasible results.

TECHNICALAND ECONOMIC ANAL.YSIS

OF ON-SITE

BIODEGRADATION

PROCESSES

As an example of the technical and economic analysis approach

to

evaluating conceptual remedial alternatives, a slurry-phase biodegradation

process for treatment of soils contaminated with organic compounds is

considered. A conceptual process is shown in

Figure

1.

The solids are

excavated, screened to remove oversize solids (which in this case, for

simplicity are o nly a small fraction), an d conv eyed to storage bins. From the

bins, the solids are conveyed

to

one

of

the bioreactors. The reactor

is

partially

filled with liquids before the solids are added. One tank is used

for

the

preparation of the chemical reagentdnutrients an d the addition of microor-

ganisms, if needed. The bioreactors are operated in batch m ode. When the

reaction is com plete, the slurry is discharged to settling pond s, wh ere most of

the solids separate from the solution. The overflow solution is fdtered and

collected in a tank for analysis prior to recycle or discharge. The treated

sol

can

be

returned to the excavation area after analysis indicates that the levels

of

contaminants a re

below

the target conce ntrations.

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PA U L R. AMMA GAYLE. KOCH

Figure 1. Conceptual Slurry-Phase Biodegradation Process.

Preparat ion Tanks

7

Waste Liquid

Storage Tanks

Recycle to Process

To disposal

Treated Soil

The process operating parameters are described in

Table

1.

It

is

assumed that the plant ope rates 350 days a year, twenty-four hours a day.

The

soil

slurries are h eated

to

the optimal temperature for the biodegra-

dation process.

As an illustration, a factored ca pital cost estimate for a project has been

developed an d is shown in Table 2. For this process the total investmen t

is calculated at about 2.3 million. N o t e that

it is

important to include all

foreseen capital costs, including not only purchased equipm ent, but also

installation, instrumentation, and other ancillaries, foundations and

site

improvements, land, engineering design, startup, taxes, and any other

exp ected costs. In addition, contingencies in the range of 5 percent to 35

percent should

be

added ; the amount

is

related

to

the level

of

engineering

detail available at the time of the estimate.

A n estimate of the operating costs is shown in Table 3. For this

example, the cost of chemical reagen ts is estimated at about 45per cubic

yard

( 33

per ton)

of

soils.Although most of the reagent costs should be

low, hydrogen peroxide, for example, could

be

very expensive. The

electrical energ y costs are calculated at ab out $20

per cub ic yard

( 15

per

ton). Intrinsically, the electrical m achinery requirem ents ar e low,However,

because of the long treatment times, the energy of the mixers in the tanks

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TECHNICALND ECONOMICNALYSESN THE DEVELOPMENTF B I O R E M E D I A ~ O NROCESSES

Table

1

Operating Parameters for the Slurry-Phase Biodegradation

Process.

Annual operation

Bioreadors

50

weeks per year

7 days per week

350 days per year

24 hours per day

20,000 gallons each

3 reactors

days per week

1 shift per day

25 to 30 percent

oils

slurry density

Operating

temperature

20

to 30

degrees Centigrade

Granular,

sandy soils

Table

2.

Illustrative Capital Cost Estimate for the Slurry-Phase

Biodegradation Process.

Item

Purchased equipment

Equipment installation

Insulation

Instrumentation and control

Piping

Electrical installation

Buildings and foundations

Yard improvements and service facilities

PHYSICAL

COST

Land

SUBTOTAL

Engineering design and construction

Stamp expense

Sales taxes and shipping costs

8

750

1 550

1 550

750

2 300

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PAULR AMMA GAYLE

.

KOCH

Table 3. Illustrative O perating Costs for Slurry-Phase Biodegradation

Process.

Bases: 5,924 cubic yards per

year

350

days

per

year

24

hours per day

New Investment: $2,226,901 (with 25%contingency)

Item

Unit

Cost ( /yd3)

1.

PROCESS MATERIALS

Reagents and miscellaneous

2.

UTILITIES

Electrical

energy

3. OPERATION

Hourly

and supervision

4 MAINTENANCE

Labor

and supplies

5. SAMPLING

AND

CHEMICAL ANALYSIS

6. OTHER

DIRECT OPERATING

COST

45

2

60

30

40

20

215

may beco me significant. Here is on e exam ple

of

ho w minimizing reaction

times can reduce operating costs. Th e third com ponen t is the cost

of

hourly

labor and supervision. The staffing requirements are very im po rta nt -to

minimize costs, the process should operate unattended as much as

possible. For the small throughput in this example, the labor and

supervision costs are estimated at abou t

$60

per cubic yard

( 45

pe r ton).

This example illustrates how th e con ceptua l design mu st consider staffing

needs.

Another cost item is maintenance-in this exam ple the cost is

calculated at about $30per cubic yard ( 23 pe r ton). Maintenance is directly

related to the plant d esign; the us e of state-of-the-art equ ipm ent an d simple

process designs can minimize maintenance nee ds. Because operation

is

at

ambient temperatures,

maintenance should be less of a factor in

bioremediation p rocesses than, say, high-temperature incineration equip-

ment. Sampling an d analysis

costs

we re estimated at 40 per cub ic yard

($30

per

ton).

If

the remediation

is

carried out by a contractor, there are typically othe r

indirect costs, which include project management and home office

suppo rt. In our example, these costs are estimated at approximately $20

per cubic yard

( 17

per ton).

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TECHNICAL

ND ECONOMICN LYSES

IN

TKE

DEVELOPMENTF

BIOREMEDIATIONROCESSES

Figure 2. Illustrative Treatment Costs for a Slurry-Phase Biodegradation Process.

400

300

9

u

Q

200

u,

c

v

u

c

.

C

=

1

0

Note : Cos ts are very spec i f ic

t

process and s i te

cond i t i ons .

There fore these cos ts shou ld not

be used for s i te or techno logy eva luat i ons .

5 10 15

20

Project Size (Thousand Cubic Yards)

I

25

Overall, the operating costs in the illustrative example total an

estimated

$215

per cubic yard

($165

per ton). These costs are for a

particular plant design and operating rate. An extension

of

the analysis

to

examine the costs as a function of a project size shows the importance of

the cost components described above (Figure 2). Although chemical

reagents and utilities are almost independent of the project size, unit labor

and maintenance costs, amortization, and profit decrease with larger

quantities

of

soils tested.

In-Situ Trea tme nt

To avoid costs and potential problems associated with excavation and

handling

of soils,

significant research and development efforts are being

devoted

to

in-situ treatment of contaminated soils and groundwater.

Concepts include biodegradation, and chemical and thermal processes, as

described earlier.

A conceptual in-situ biodegradation process is illustrated in Figure 3.

In contrast to the slurry phase reactor in Figure

1

the surface facilities are

reduced to essentially solution storage tanks, reagent makeup tanks, and

solution filtration equipment. A n array of injection and recovery wells

replace the slurry-phase bioreactors and the solids handling equipment.

125


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PAULR

AMMA

GAYLE.

KOCH

Figure

3.

Conceptual In-Situ Biotreatment Process.

Reagent Preparat ion Tanks

The net effect is a lower investment. An important difference, however,

is

that a slurry-phase reactor provides the most intimate contact between the

liquid and

soil

phases for reaction, whereas the naturally occurring ground

is an imperfect reactor for carrying out chemical reactions.

Estimates

of

the operating costs, assuming similar solution composi-

tions to the slurry-phase treatment process, are presented in Table 4 . The

apparent advantage

is

lower utilities, operation, and maintenance costs.

What is not captured in this cost estimate for in-situ treatment

is

the fact

that the overall effectiveness

for

contact between reagents and the

contaminants maybe very low and cleanup standards may not be reached

except after extraordinarily long times. Hence, treatment costs may actually

be more expensive than projected.

FOCUS OF R D

biodegradation system should be

to:

This simple analysis shows that the focus of research on this conceptual

1. Demonstrate adequate degradation

of

the hazardous organics to

meet cleanup standards.

126

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TECHNICAL

ND

ECONOMICN LYSESIN THE DEVELQPMENTF BIOREMEDIATIONROCESSES

Table

4.

Illustrative Operating Costs for In-Situ Biotreatm ent.

Bases: 5,000 cubic yards per year

350

days per year

24 hours per day

New Investment:

$600,000

Unit

Cost ($/yd3)

tem

1.

PROCESS MATERIALS

Reagents and miscellaneous

2. UTILITIES

Electrical energy

3.

OPERATION

Hourly and

supervision

4 . MAINTTNANCE

Labor

and supplies

5 SAMPLING

AND

CHEMICAL

ANALYSIS

6

OTHER

DIREC OPERATINGCOST

5

3

40

7

40

15

150

2.

Ascertain cond itions that achieve the m aximum rates wh ile attaining

the goals

of

sufficient

or

complete b iodegradation.

3. Select reaction co nditions that use the lowest-cost reagents.

Laboratory stud ies should be conducted so that, to the extent possible, the

reaction cond itions simulate the larger scale reactions.

The next

step

in the evaluation p rocess is to compare the bioremediation

parameters

to

com peting alternative technologies. Is 215 per cubic yard

high or low? Is the process equally competitive at high volumes as at low

volumes? How does the process co mp are in me eting clea nu p goals? Will

permitting and public acceptance

be

an advantage or disadvantage

compared

to

alternative technologies? What is the likely return o n further

investment in

R&D?

If

these issues are addressed early, the success

of

bioremediation R D can

be

improved significantly by providing focus to

the

effort

and building the m anagement suppo rt critical for project success.

CONCLUSION

Biotreatment processes provide alternatives for the remediation of

contaminated

solids,

such as soils, sludges, and sediments, and for

contaminated groundwater. Engineers and regulators faced with the

remediation of these sources of toxic compounds have many treatment

R E M E D L A T I O N ~ ~ ~ R993/94 127


14/14

PAULR

AMMA GAYLE

.

KOCH

alternatives from which to select. Many thermal, physical, chemical, and

biological treatment processes have been demonstrated on a large scale

and are

in

use. None

of

these processes

is

universally applicable

to

all

situations because of technical limitations and/or unacceptably high costs.

Bioremediation processes offer attractive options in situations where

organic contamination

is

the primary problem; and in many situations, the

costs are lower than competing technologies. However, before embarking

on potentially expensive and time-consuming R&D, it is important

to

examine technical and economic feasibility. By identlfying early on the

parameters that will lead

to

success, and by understanding alternative

technologies and their competitive position

in

the remediation market

place, companies can more effectively guide their R&D projects to

successful commercial results.

REFERENCES

1.

Jerger, D.D ., D.J. Cady, and J.H. Exner. 1993. Full-Scale Slurry-Phase Biological

Treatment

of

Wood-PreservingWastes.Paper presented at In Situ and On-Site Bioreclamation,

the S econd International Sympo sium, San Die go, April 5-8.

2.

Lewis, Ronald

F.

1993. SITE Dem onstration

of

Slurry-Phase Biodegradation

of

PAH

Contaminated Soil .

k

G

aste

43cApril): 503.

128 REMEDIATION/WINTER

993/94

Remediation Journal Volume 4 issue 1 1993

Documents

Transcript of Remediation Journal Volume 4 issue 1 1993