An Introduction to Environmental Chemistry

130 Chapter Four

Organic compounds

in soil

Changes inmobility

Changes in

toxicity

Enhanced mobility

Reduced mobility

Decreased toxicity

Increased toxicity

Phenanthrene

HO

OH

3,4-dihydroxyphenanthrene

Increased polarity = greater solubility

Reduction to aminofuntional groupsenhances binding tosoil organic matter

1,3,5-Trinitrotoluene

NO

2

CH

3

H^2

N

NH

2

SOM

Pentachlorophenol

Pentachlorophenol

Pentachlorophenoxy-tetrachlorophenol

NH

2

CH

3

O^2

N

NO

2

CH

3

H^2

N

NH

2

NH

Pentachloroanisol

OH

Cl

Cl

Cl

Cl

ClOCH

3

Cl

Cl

Cl

Cl

Cl

OH

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

Cl

HO

O

Cl

Cl

Cl

Cl

Cl

Interaction with the soil

Degradation

Mineralization

Fig. 4.30

Changes in toxicity and mobility of organic contaminants caused by biodegradation and biotransformation. SOM, soil

organic matter.