INTRODUCTION TO BIOREMEDIATION

Superfund Remedial Action Technology Selected FY94

Breakdown of Sites by Type of Contaminant

Percentage of Sites Treating Each Medium

Groundwater32%

Soil59% Sediment

6%

Sludge2%

Surface Water1%

Breakdown of Process by Treatment Technology

(includes laboratory-, pilot-, and full-scale)

In situ68%

Ex-situ (with reactor)

15%

Ex-situ (without reactor)

17%

Top 9 BIOREMEDIATION METHODS

Solid Phase, prepared bed

11%

Soil Bioremediation

14%

Ground Water Bioremediation

14%

Bioventing25%

All Other Method11%

Attached Growth5%

Air Sparging6%

Fixed Film4% Solid Phase, pile

treatment4%

Natural Attenuation

6%

ENVIRONMENTAL BIOTECHNOLOGY

• The direct use of microorganism and their capabilities to solve environmental problems

• Disciplines involves: engineering, molecular biology, ecological sciences

Biodegradation’s relation to Environmental Biotechnology

Biodegradation

Cradle to Grave

Bioremediation

Waste

wate

r Tre

atm

en

t

Biomass Utilisatio

n

Database Pollution

Resource for Development Bio

degra

dable

Biofuels

Conservation Technology

Renewable Resources

Direct Environmental Response

What is BIOREMEDIATION

• The technology used to speed up the natural processes of waste degradation and recycling

• Use of naturally occurring microorganism such as bacteria, fungi, and yeast to degrade pollutants or hazardous substances in soil, water and air into non-toxic or less toxic substances

BIOREMEDIATION

is a method that treats the soils and renders them non-hazardous,

thus eliminating any future liability that may result from

landfill problems or violations.

WHY BIOREMEDIATE?

• Soils contaminated with hydrocarbons may be disposed of or treated in several ways: Regulated permitted landfills, thermal incineration and bioremediation.

WHY BIOREMEDIATION?

• Sites awaiting clean-up (1993)• Agency Responsible Number of Sites• US EPA Superfund 1,500-2,000 • RCRA 1,500-3,000 • UST’s 295,000 • US DoD 7,300 • US DOE 19,000

Why Bio? II

• Adapted from Cookson, 1995• Complete citation:

U.S. EPA. 1993. Cleaning up the Nation’s waste sites: Markets and technology trends. EPA/542/B-92/003 These are mainly petroleum, VOC’s, or PCB’s

Why Bioremediation? III

• Frequency of Contaminant Subgroups (US EPA TIO, 1992)

• US. EPA/540/N-93/001

Major Waste Types Applicable to Bioremediation

WHY BIOREMEDIATION? IV

WHY BIOREMEDIATION? V

Cost Effectiveness of Bioremediation ($)

Method Year 1 Year 2 Year 3Incineration 5301 None None Solidification 115 None None Landfill 670 None None Thermal Desorption 200 None None Bioremediation 175 27 20

1 - costs are per cubic yard

Adapted from Cookson, 1995

TREATMENT COST

• Landfill disposal costs range from $15- per m3 to over $75 per m3 depending on hydrocarbon concentration. Timing from 6 to 24 months .

• Thermal incinerationis fast but  costs range from $250  to over $700 per m3 which dpends of the type of soils

• Bioremediation costs range from $90  to $110 per m3. the timing is between 30 to 120 days

WHY BIOREMEDIATION? VI

• Some Other Advantages of Bioremediation• Can be done on site • Permanent elimination of waste (limiting liability) • Positive public acceptance • Minimum site disruption • Eliminates transportation cost and liability • Can be couple with other treatment techniques

Adapted from Cookson, 1995

Advantages of Using Bioremediation Processes

Compared With Other Remediation Technologies

(1) biologically-based remediation detoxifies hazardous substances instead of merely transferring contaminants from one environmental medium to another;

(2) bioremediation is generally less disruptive to the environment than excavation-based processes; and

(3) the cost of treating a hazardous waste site using bioremediation technologies can be considerably lower than that for conventional treatment methods: vacuuming, absorbing, burning, dispersing, or moving the material .

Effective Bioremediation, Utilizing Microbial Inoculation,

Basic and Absolutely Essential Requirements

1. Oxygen at a residual level of 1 ppm. or more 2. Essential inorganic nutrients 3. Microbes and substrate must be in contact 4. Water - either salt or fresh Other conditions must be taken into account, such as

pH, temperature, salinity, type of contaminant,

POLLUTANTS

– Bio-degradable petroleum products (gas, diesel, fuel oil) •crude oil compounds (benzene, toluene, xylene, naphthalene) •some pesticides (malathion) •some industrial solvents •coal compounds (phenols, cyanide in coal tars and coke waste)

– Partially degradable / PersistentTCE (trichlorethylene) threat to ground water •PCE (perchlorethlene) dry cleaning solvent •PCB’s (have been degraded in labs, but not in field work) •Arsenic, Chromium, Selenium

– Not degradable / Recalcitrant Uranium •Mercury •DDT

PAH structures

Adapted from “A Citizen’s Guide to Bioremediation”, United Nation Environmental Agencies, Office of Solid Waste and Emergency Response, EPA 542-F-01-001

CHALLENGES OF INNOVATION

• Technology Quality / Success• Available Market • Investment Capital • Competent Management • Regulatory Acknowledgment • Right Timing • Good Public Perception • Good Information Dissemination

Remediation Options for Organic Pollutants

in Soils– Containment/landfill– Thermal desorption– Advanced organic stabilisation– Mobile catalytic chemical oxidation– Bioremediation

• Landfarm• Biopile• Composting• Slurry reactors

COMPARISON OF BIOREMEDIATION AND OTHER TECHNIQUES

• Soil Gas Extraction: A process by which petroleum vapors are removed from the soil using wells and vacuum pumps. Volatile compounds are extracted from the area between soil particles by applying negative pressure to screened wells in the vadose zone.

• Low Temperature Thermal Stripping: A process by which soil is excavated and fed into a mobile unit designed to heat the soil and drive off contaminates.

• Excavation: A process which involves the digging up of contaminated soils and hauling them away.

TYPES OF TREATMENT TECHNOLOGY

Bioaugumentation

• the addition of naturally occuring microbes to sites

• sites can be treated with high concentrations of specific microbes

• costs little money, time and disruption• simple testing done for

biocompatibility and biodegradation efficiency

TYPES OF TREATMENT TECHNOLOGY

Biostimulation

• The use of indigenous microbes • the modification of the site to promote

the growth of native microbes already present

• depends on necessary native microbial and organic material to be present

• costs little time and money • testing appropriate microbes can be

difficult and complex

TECHNOLOGY-OTHER OPTIONS

Bioventing – treating soil by drawing oxygen though it to

stimulate microbe growth

Composting – contaminated soils mixed with a bulking agent and

exposed to air

Landfarming – adaptation of traditional farming techniques

(aerating, ploughing) to contaminated areas to increase microbes activity

Treatment Options for Contaminated Soils

from Natusch, 1997.•Remediation Method•Excavation-landfill•Containment on-site•Landfarming/Bio•Co-burning•Stabilisation•Thermal desorption•Soil washing•Vapour extraction•Dechlorination

•% Use in Australia•60-90•10-30•15-20•<5•5-10•<5•<5•<5•<1

Limitations to Bioremediation

– Timescale– Residual Contaminants Levels– Inconsistency– Recalcitrant Pollutants eg DDT, PAHs

• Bioavailability• Degrading microorganisms• Aqueous solubility• Toxicity

ConclusionBIOREMEDIATION:

• Is a process which uses naturally occurring microorganisms to enhance normal biological breakdown.

• It is an effective method for treating many hazardous materials.

• Of all the different processes available for clean-up of sites, Bioremediation is the best and most cost effective method for remediation, with respect to environmental liability.

• The nature and location of the contamination, the type of soils and geological conditions, determine which method of remediation is best for each individual clean-up site.

What is What is NextNext

“Plan the Work, and Work the Plan” An Engineering Perspective

•Planning the Work •what is to be done •when is it to be done •how much is the scheduled cost •who will do it •Working the Plan •budgeting & scheduling control •coordinating activities across the team •How to Evaluate & Recommend the Technology •must provide a net improvement over conventional

technologies •goals must be achieved: •faster, cheaper, safer, better, etc.

Cookson, 1995

END OF INTRODUCTION TO BIOREMEDIATION