Environmental Engineering Reference
In-Depth Information
1
Plastics Induced Ocean Pollution
Thangavelu Muthukumar and Mukesh Doble
Plastics are made up of synthetic organic polymers, which have emerged as the most
ubiquitous material invented by humans. Plastics have replaced other materials
in the building, construction, shipbuilding and automobile industries. They are
non-degradable, and thus, when they are disposed of, after their useful life, they
persist in the environment for a very long time. They have numerous advantages
including their light weight, strength, durability, versatility, resistance to moisture
and low cost of production [1]. One-third of the earth's surface is covered by oceans.
The largest ecosystem is our oceans and any damage or changes within this system
affects humans. Humans have used the ocean throughout history to dump and dispose
of waste including non-biodegradable material such as plastics. Globally plastic items
are ranked among the most abundant type of marine debris and the pollution caused by
them is growing every day [2]. Polymers used in marine applications include polyester,
polyethylenes (PE), luorinated hydrocarbons, foams and urethanes.
Table 1.1
gives
a list of polymers used in the marine environment, a few of their properties (surface
energy, contact angle and surface roughness) and their applications. So it is expected
that all these polymers as well as those used inland may be polluting the ocean. These
polymers have a wide range of surface properties and thus, the type of biofoulants
and the extent of biofouling may vary considerably.
Table 1.1 Polymers used in marine applications and their properties
Polymers
Composition and applications
Surface
energy
(mN/m
±
SD)
Contact
angle(degrees
±
SD)
Surface
roughness
(µm)
Polydimethyl-
siloxane
Surface free energy fouling release
coatings
35 ± 2.5
101.5 ± 1.7
47.24
Silicone
rubber
Used for making marine and dock
fenders
36 ± 3.8
95.5 ± 2.38
168.49
