ocean. Nonpoint sources of pollution are those which comes from different sources
of origin and number of ways by which pollutants enter into groundwater or surface
water and reach the environment from diverse nonidentifiable sources. These may
include storm water runoff or agricultural or debris that is blown into waterways
from the land. Nonpoint source pollution is the prime and undeniable cause of water
pollution in the United States waters, but it’s difficult to regulate since there’s no
single, identifiable culprit.
3.3 Causes of Water Pollution
Water pollution is caused by multiple factors such as untreated industrial waste,
municipal waste, and leaching of heavy metals from soil into the ground water.
Ocean and most of the land-based water systems are polluted mainly because of
human activities. Industrialization has resulted in the development of products that
have turned to pollutants due to their overproduction, use, and nondisposable
conditions. Plastic is one of the major causes of water pollution around the globe.
This chapter is concerned with the water pollution caused by plastics, so we will be
concerned here in detail about how plastics pollute our marine and fresh water
sources. The solutions and remedies to counter water pollution are also discussed.
3.3.1 Plastic as a Water Pollutant
The term plastic came from the Greek word “plastikos”, meaning ability to change
into different shapes (Shah et al. 2008). Plastics consist of various elements such as
carbon, oxygen, nitrogen, hydrogen, chlorine, and sulfur. Plastics are synthetic
organic polymers similar to naturally existing biopolymers such as wool or wood
which are chemically large molecules called polymers composed of repetitive units,
called monomers, with carbon backbones. To produce polymers, petrochemicals,
and their derivative products are heated under controlled conditions and broken
down into simpler residues or small molecules known as monomers (Halden 2010).
Different types of monomers make plastic resins with different characteristics, such
as molding capability or strength. That monomers can be extracted from oil, natural
gas, or coal. The five major classes of plastics (90% of polymer production) more
common in the ocean comprise polypropylene, polyvinyl chloride, polystyrene,
polyethylene, and polyethylene terephthalate (Thevenon and Carroll 2015).
On the basis of thermal properties, plastics can be divided into two major
categories: thermoplastics and thermosets. Thermoset plastic hardens or sets irreversibly when heated at a considerable temperature. These plastics are important for
their strength and durability. Therefore, they are used primarily in automobiles and
construction applications. Plastic also finds some applications in adhesives, inks, and
coatings. On the other hand, molecules in thermoplastic polymer have weaker bonds,
3 Remediation of Water Pollution by Plastics
93
of origin and number of ways by which pollutants enter into groundwater or surface
water and reach the environment from diverse nonidentifiable sources. These may
include storm water runoff or agricultural or debris that is blown into waterways
from the land. Nonpoint source pollution is the prime and undeniable cause of water
pollution in the United States waters, but it’s difficult to regulate since there’s no
single, identifiable culprit.
3.3 Causes of Water Pollution
Water pollution is caused by multiple factors such as untreated industrial waste,
municipal waste, and leaching of heavy metals from soil into the ground water.
Ocean and most of the land-based water systems are polluted mainly because of
human activities. Industrialization has resulted in the development of products that
have turned to pollutants due to their overproduction, use, and nondisposable
conditions. Plastic is one of the major causes of water pollution around the globe.
This chapter is concerned with the water pollution caused by plastics, so we will be
concerned here in detail about how plastics pollute our marine and fresh water
sources. The solutions and remedies to counter water pollution are also discussed.
3.3.1 Plastic as a Water Pollutant
The term plastic came from the Greek word “plastikos”, meaning ability to change
into different shapes (Shah et al. 2008). Plastics consist of various elements such as
carbon, oxygen, nitrogen, hydrogen, chlorine, and sulfur. Plastics are synthetic
organic polymers similar to naturally existing biopolymers such as wool or wood
which are chemically large molecules called polymers composed of repetitive units,
called monomers, with carbon backbones. To produce polymers, petrochemicals,
and their derivative products are heated under controlled conditions and broken
down into simpler residues or small molecules known as monomers (Halden 2010).
Different types of monomers make plastic resins with different characteristics, such
as molding capability or strength. That monomers can be extracted from oil, natural
gas, or coal. The five major classes of plastics (90% of polymer production) more
common in the ocean comprise polypropylene, polyvinyl chloride, polystyrene,
polyethylene, and polyethylene terephthalate (Thevenon and Carroll 2015).
On the basis of thermal properties, plastics can be divided into two major
categories: thermoplastics and thermosets. Thermoset plastic hardens or sets irreversibly when heated at a considerable temperature. These plastics are important for
their strength and durability. Therefore, they are used primarily in automobiles and
construction applications. Plastic also finds some applications in adhesives, inks, and
coatings. On the other hand, molecules in thermoplastic polymer have weaker bonds,
3 Remediation of Water Pollution by Plastics
93