Soil Science
Chapter 18. Soil and chemical pollution
(*: important concept)
Zueng-Sang Chen (陳尊賢)
Tel: 2369-8349, soilchen@ntu.edu.tw; http://Lab.ac.ntu.edu.tw/soilsc/
Printed on Dec 25, 2004
18.1 Toxic organic chemicals
 * artificially synthesized industrial xenobiotics (Fig. 18.1, p798) including PCB, TEC, PAH, TNT, PCP.
 Insecticides (DDT, Carbaryl, & parathion) and herbicides (Alachlor, EPTC, 24-D, Trifluralin, Linuron,
Glyphosate, and Atrazine)
18.3 Behavior of organic chemicals in soil
 * Seven reaction in soil system: volatilization, adsorption, leaching, runoff, adsorption and exudation,
chemical decomposition, biological degradation, photodecomposition (Fig 18.3, p802)
 * Five types of off-site damage: Eutrophication, turbidity, windblown dust, human health hazard
materials, and loss the productivity.
18.5 Remediation of soil contaminated with org chemicals
 * in situ and ex situ treatment (Fig 18.10, p811)
 * washing by surfactants, desorption by heating, bioremediation, phytoremediation and natural
attenuation.
 * Bioremediation by enhanced microbial breakdown of contamination: Many case syudies
 * two approaches of phytoremediation: Hyperaccumulator and enhanced rhizosphere adsorption by
plants.
18.6 Contamination of toxic inorganic substances
 * Sources of inorganic soil pollutants: As, Cd, Cg, Cu, Pb, Hg, Ni, and Zn (Table 18.7, p819)
 * regulation of inorganic pollutants in sewage sludge applied to agricultural soil. (Table 18.9, p822)
18.10 Landfills
 *Two basic types of landfill design (Fig 18.24, p829)
18.11 Radionuclides in soils
 strontium 90, cesium 137, Iodine 131, Plutonium 239, Uranium 238
Discussion:
1. Discuss the types of reactions pesticides undergo in soil, and indicate what we can do to encourage or
prevent such reactions?
2. What is bioremediation? And what are its advantages and disadvantages compared with physical and
chemical remediation for organic wastes?
3. What are the comparative advantages and disadvantages of in situ and ex situ means of remediating soils
polluted with organic compounds?
4. What are two approaches of phytoremediation, and for what kinds of pollutants are they useful> explain.