Hazardous Waste: What Soil Fits Its Taste?

Overview

Objectives/Goals In my experiment I wanted to find out what soil type would be most effective so that hazardous waste would not contaminate the ground water. I had two main goals when preforming my experiment. Achieve a general understanding of the chemical and physical effects that soil has on a contaminant through the process of a chemical reaction in the soil column. Determine what soil type chemically and physically really has the best positive effect on not contaminating the groundwater. Methods/Materials To do this experiment I used two 3-foot plastic tubes, each representing a soil column. I chose four different soil types and tested them each with four different liquids/contaminants. I measured the initial pH of all of these substances. The tubes were filled with soil and poured contaminant into the tube observing and recording my findings with time. Once the contaminant was beneath the soil I measured and poured average rainfall. I recorded how far the contaminant had moved about every 1-5 minutes depending on how fast the contaminant was moving. I then calculated average flowrate and measured the pH of the contaminant coming through the soil column and compared that with the substance#s original pH. My tests measured the rate the chemical moved through the soil column and whether a chemical reaction may have occurred between the soil and the contaminant. Results The silty-clay was most efficient for slowing the contaminant down due to its impermeability, while the sand was the most permeable. Silty-clay was not effective in slowing down the acidic contaminant becuase the acid broke the organics in the soil down which caused the soil to loose its "sticky" effect. The basic soil was most effective for neutralizing acidic contaminants. Flowrates ranged from .005in/min to 1.36in/min for the experiments preformed. Conclusions/Discussion I concluded that without rainfall the liquid would not move through the column. This means that if the contaminant is disposed of in arid or dry environments, it will not move downward, eliminating the potential for ground water contamination. Also, lining a landfill with either an acidic or basic soil, depending on the contaminant, would be useful. This would neutralize the contaminant just before it reached the water table, again eliminating the potential for ground-water contamination.

Awards (1)

• First Place

Competition history

• CSEF 2007 Environmental Science (Junior Division Only) · Entry J1007

Resources

• CSEF project summary ↗

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Environmental Analysis projects
• CSEF Environmental Analysis projects
• Every CSEF 2007 project
• CSEF First Place winners