Consider the questions below as you watch the video.

Do you think it’s important for the citizens of China to know the results of the Soil Pollution test? Do you think soil contamination is a problem we need to be concerned about? Explain. Click on picture above to

view video.

Introduction

Soil Remediation

Today, you will learn about the connection between

chemistry, engineering, and soil remediation (clean-up).

Current Soil Remediation Methods1) Incineration

Burning the Soil; Requires a large amount of energy and produces a hazardous by-

product from burning HHOCs.

Figure 1: Incineration of Soil

Current Soil Remediation Methods2) Solvent Extraction

Using a solvent to treat the soil; creates more waste that must be treated for HHOCs which means more money.

Figure 2: Solvent Extraction

Something New from USF REACH technology

The remedial extraction and catalytic hydrodehalogenation (REACH) technology treats the soil by solvent extraction and catalytic hydrodehalogenation (HDH).

Reach Technology Model

Recycled Solvent Reservoir

Starting Point: Contaminated Soil

Column

Solvent is extracted from soil. It now contains HHOCs.

Solvent is now contaminated with HHOCs.

Catalytic HDH Reaction

This Catalytic Hydrodehalogenation (HDH) breaks down the HHOCs in the solvent. The products volatilize and the solvent is recycled.

This technology eliminates the additional waste produced by traditional soil remediation

methods.

REACH Technology

REACH technology was introduced by Hun-Young Wee, Department of Civil Engineering at Texas A&M University, and Jeffrey A. Cunningham, Department of Civil & Environmental Engineering at University of South Florida. His current graduate students, Margaret Cone and Bobby Panczer, are working on projects related to remediation of soil contaminated by hazardous chemicals such as HHOCs.

You are now one of his assistants in the lab.

ProblemHalogenated hydrophobic organic compounds (HHOCs), a type of soil contaminant, does not mix well with water or evaporate into the air completely. It can take years for these contaminants to break down. Therefore, a more effective technique is needed to clean the soil of the HHOCs.

The HHOCs you will be investigating is 1,2,4,5-tetrachlorobenzene (TeCB).

1,2,4,5-Tetrachlorobenzene (TeCB)

Formula: C6H2Cl4

Use the chemical formula to calculate the molar mass of TeCB. (Show your work and include units!)

Use http://www.inchem.org/documents/icsc/icsc/eics0676.htm to research the hazards (human and environmental) of TeCB.

Figure 4: 1,2,4,5-tetrachlorobenzene

Control ExperimentREACH Technology

You will analyze data from control experiments to determine whether the disappearance of TeCB is due to HDH or adsorption.

What is adsorption and volatilization? (Include your source.)

References

1. H.-Y. Wee, J.A. Cunningham, Palladium-catalyzed hydrodehalogenation of 1,2,4,5-tetrachlorobenzene in water–ethanol mixtures, Journal of Hazardous Materials 155 (2008) 1–9

2. Wee, H-Y. and Cunningham, J.A. (2013) ‘Soil treatment by solvent extraction and catalytic hydrodehalogenation’, Int. J. Environment and Waste Management, Vol. 11, No. 1, pp.59–74.

3. http://www.epa.gov/superfund/students/wastsite/soilspil.htm 4. Figure1: www.epa.gov visited on 7/29/20135. Figure 2: www.infohouse.p2ric.org visited on 7/29/20136. Figure 3: www.pubs.rsc.org visited on 7/29/20137. Figure 4: www.wtt-pro.nist.gov visited on 7/29/2013