Page 190 - Soil and water contamination, 2nd edition

Organic pollutants 177

photochemical processes. Synthetic textile fibres originate from the abrasion of synthetic
textiles (e.g. nylon, polyester, acrylic) during domestic clothes washing. They are transported
in the rinsing water, eventually ending up, via the sewage system, in surface waters.
In recent years, microplastics have been found in sediments in inland waters and seas
worldwide (e.g. Andrady, 2011; Browne, 2011; Faure et al., 2012). Primary microplastics
that enter the aquatic environment can easily be transported by rivers to seas and oceans.
Nevertheless, the majority of microplastics found in oceans are secondary microplastics, but
80% the plastic litter from which they originate have terrestrial sources including beach litter
(Andrady, 2011).
As well as being pollutants themselves, microplastics are also carriers of two types of
micropollutants: native plastic additives and adsorbed hydrophobic pollutants (e.g. POPs).
As seen in section 9.7.3, some plastic additives may have endocrine-modulating properties.
Although microplastics have been frequently found in the digestive tracts of various aquatic
and marine organisms, little is known about their effects on aquatic life and ecosystems.
Potential effects of ingestion of microplastics by organisms are reduced food intake due to
false satiation, blockage or physical damage of digestive tract or feeding appendages, leaching
and bioaccumulation of sorbed pollutants by the organism, and transfer of these pollutants
across the food chain.

EXERCISES

1. Define the following terms:
a. Isomers
b. Aromatic
c. Aliphatic
d. Cis and trans isomers
e. PAHs
f. VOCs
g. POPs
h. NAPLs
i. BTEX
j. CDDs
2. a. Give the chemical formulas of the following substances:
- 1,2-Dichlorocyclohexane
- Biphenyl
- Anthracene
b. Draw the structure of
- 3-bromo-2-chloro-2-methylbutane
- 1,2,4-trichlorocyclohexane
- cis-1,2-difluoroethene
- m-dichlorobenzene
3. Describe in brief the fate and toxicity of 1000 litres of oil spilled
a. into a sandy soil with a shallow water table;
b. into a peaty soil;
c. into a lake.

4. a. What can be said about the water solubility of PAHs?
b. To which sediment components do PAHs adsorb in particular?

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