"You must be the change you wish to see in the World." 

Gandhi 

Presented by:

JoLeta Brandsgaard, Butch Granada, Angela Myers, and Debra Van Hoosen

Introduction

Humans need a safe water supply and a safe method of sewage disposal. While half the population in the United States get their water from groundwater, most Americans live within 10 miles of a polluted body of water.  Most bacteria is found in the top 12 inches of soil.

Our group focused on sewage treatment and output from a treatment facility entering Stonybrook stream which fed into nearby Lake Carnegie. The treatment plant used a method of bioremediation of which our group tested the microbial activity and compared it to lake water. In addition our group investigated various factors that affect the bioremediation process.

The Environmental Protection Agency produced a citizen’s handbook to address question about bioremediation.

What is bioremediation?

Microorganisms are used to change harmful substances to nontoxic substances. This is a new technology for treating chemical spills and hazardous waste.

How does it work?

Bacteria, fungi and yeast need nutrients (such as carbon, nitrogen, phosphate, and trace metals) to survive. They break down organic (carbon-containing) compounds found in nature to get energy for growth. For example, soil bacteria use petroleum hydrocarbons as a food and energy source changing them into harmless substances of carbon dioxide, water and fatty acids.

How long has it been in use?

Composting, sewage treatment and certain types of fermentation have been practiced since the beginning of recorded history. The more "modern" use of bioremediation began over 100 years ago. Within the last 10 years microbial processes are beginning to be used in the clean up of radioactive and metallic contaminants. These include: cesium, chromium, lead, mercury, plutonium, uranium, strontium, and technetium.

What bioremediation techniques are currently used at hazardous waste sites?

If the contamination is in the top part of the soil (less than 12 inches) it can be treated by tilling the soil to provide aeration and by adding nutrients and water for bacterial growth.

Sometimes oxygen must be delivered to the contaminated area for the respiration process because oxygen is not very soluble and easily depleted. This is done by withdrawing the ground water, adding an oxygen source such as (air, pure oxygen, hydrogen peroxide, or ozone) and re-injecting the water using injection wells or trenches.

2.    Above ground bioremediation

Slurry-phase treatment is a process that combines contaminated soil with water to create a slurry, which is broken down in a bioreactor. If necessary, nutrients and oxygen can be added. The soil and water are separated after treatment.

Solid-phase treatment is another treatment where contaminated soils are placed in a treatment bed where nutrients, moisture and oxygen are added for decomposition to take place.

3.    Combined treatment

Many waste sites contain complex mixtures and need a combination of treatment techniques.

What are the advantages of bioremediation?

1. It is a "natural process". It usually does not produce toxic by-products.
2. Bioremediation destroys the target chemicals.
3. Bioremediation is usually less expensive than other technologies.
4. It can be used where the problem is located.

What are the disadvantages?

1. More research is needed for locations with complex mixtures of contaminants.
2. Clean up using bioremediation often takes longer than other actions such as incineration.
3. The process must be carefully monitored to ensure the effectiveness.

Sewage Treatment Plant

This describes the action of bacteria in biodegradation at the Stony Brook Sewage Treatment Plant.

Experiments

There were three experiments relating to the water quality of Lake Carnegie. These included:

* The Biological Oxygen Demand,

* Eutrophication level, and

* Sorption Isotherm.

Data

* The Biological Oxygen Demand,

* Eutrophication level, and

* Sorption Isotherm.

Conclusions

Bioremediation can bring contaminated groundwater within U.S. drinking water standards within six months. It is a technological tool that holds great value for the future. As scientists learn more about its capabilities, it is likely to become one of the best technologies used to clean up and protect our environment.

Through our experiences at the Woodrow Wilson National Fellowship Foundation, we have a greater understanding of the importance of water quality. We came to the mentor group knowing very little about bioremediation. After working with Hyun-su Kim, we have increased our knowledge of the different ways that humans are trying to impact this area through technological modules. We have enjoyed our experiences, namely the lab work and the opportunity to see a sewage treatment plant first hand. We hope to use these experiences not only in the classroom, but to share what we have learned with colleagues. Collaboration is the key to progress and we must continue to be catalysts for change.