AGEN 2363 notes.  Chpt. 16.  Soil Pollution.

 

I. Introduction.

     A. Soil acts like a giant filter cleaning up contaminated water of organics, and most

          toxins.  As the world’s population increases dramatically, maintaining soil vitality

          is of most importance. 

 

     B. Detrimental effects of soil contamination.

            1. ground water

            2. crop productivity

            3. wildlife

            4. cleanup $$$

 

II. Types and sources of soil pollution.

    A. Human activity.

            1. solid waste –

 

            2. hazardous solid waste –

 

            3. liquid wastes (normal and hazardous) –

 

                        - sewage treatment plants –

                        - soil filtration disposal septic systems –

 

            4. litter! 

 

            5. Importance of recycling:  cans, plastics, paper, old tires, oil, etc

 

            6. pharmaceuticals –

 

            7. soil erosion/sedimentation –

 

     B. Agriculture activity.

            1. animal manures: solid, slurries

 

            2. gas (sulfur, methane, ammonia, etc) –

 

            3. fertilizers –

 

            4. pesticides –

 

            5. plant harvest by-products –

 

            6. soil erosion/sedimentation -

 

 

     C. Industrial activity.

            1. nuclear waste –

 

            2. solid wastes –

 

            3. liquid wastes –

 

            4. gaseous wastes –

 

            5. ‘aerosol’ pollution –

 

            6. soil erosion/sedimentation - 

 

III. Polluted soil.

     A. Sediment –

 

     B. Soil acidity from:          - excessive leaching

                                                - acidic fertilizers

                                                - crop removal

                                                - exposure of S compounds from tillage/drainage

 

     C. Metals from pesticides, wastes, sewage sludge:          

                        Al, Fe, Mn, Cd, Pb, Zn, Cu, Ni, As, Selenium

 

     D. Organics.  Examples:    DDT, dioxin, other polycyclic aromatic hydrocarbons (PAH)

 

IV. Soil Suitability for disposal.

     A. Liquid. (EX. sewage septic tank effluent): deep, well-drained but not excessively.

 

     B. Solid.  (EX. land fills): deep with restrictive layers to keep leaching out of ground water,

            Not subject to flooding. 

            1. Types of land fills:  a. unsecured (natural attenuation) –

 

                                                b. secured (clay + impervious, resistant fabric liners) –

 

V. Soil Remediation.

     A. ‘Superfund’ site –

 

     B. Methods of soil remediation, examples:

            1. chemical treatment/detoxify –

 

            2. bioremediation –

 

            3. removal/disposal/replacement - 

 

            4. natural renovation -