Page 23 - Materials Chemistry, Second Edition

4 Life Cycle Assessment of Wastewater Treatment

industrialization, every year, 3.4 million individuals on the planet bite the dust due to
waterborne sicknesses (Owa, 2013; Rana et al., 2017).

1.2 SOURCES OF WATER POLLUTION
The majority of water pollution is caused by the generation of contaminants from
industrial, commercial, and agricultural sources, transport, dumpsites, and other
anthropogenic activities (). Industries such as electroplating, tanning, hydrometal-
lurgical, textiles, fertilizers, pesticides, dyeing, electrochemical and motor indus-
tries, metallurgical, metal finishing, mine drainage, and battery manufacturing
play a major role in the discharge of toxic chemical substances into fresh water
(Olanipekun, 2015; Chen et al., 2015). Some of the anthropogenic activities that pre-
vail as the cause of water pollution are population growth, increased numbers of
dumpsites, leakage of sewage, deforestation, combustion, and littering (Owa, 2013).
Thus, we human beings are one of the major reasons for water pollution, and the
contaminants that are released from these industrial and commercial sources are
explained in detail in the following section.

1.3 CONTAMINANTS

Contaminants are undesirable substances that alter the quality of the water resources.
Contaminants originate from natural, industrial, and anthropogenic sources. Among
these sources, industrial contaminants are highly toxic and are not easily degradable
(Alqadami et al., 2016). The different types of contaminants present in wastewater
are heavy metals, dyes, endocrine disrupting compounds, nutrients, and microbes.

1.3.1 Toxic Heavy MeTals
Heavy metal contamination is one of the major environmental issues across the globe,
because these heavy metals are highly toxic, and it also affects human health and
other flora and fauna living on the earth (Sharma et al., 2017). The main sources of
the production of heavy metals in the environment are the industrial and domestic
sectors. These are not easily degradable, and heavy metals are capable of bioaccumu-
lating in living organisms. They can also cause some fatal disorders, such as cancer
and mutagenic disorders. The major heavy metals that affect the environment are
lead, mercury, nickel, cadmium, arsenic, chromium, zinc, copper, cobalt, and anti-
mony (Alqadami et al., 2017; Assadian and Beirami, 2014). Stringent regulations are
constituted and applied across many developing countries to remove these toxic heavy
metals from industrial effluents for the safety of the people (Ru-shan et al., 2011).
1.3.1.1 Lead
Lead is a unique, well-known industrial heavy metal. It is soft, ductile, and mal-
leable in nature. It possesses poor conductivity and high resistance against corro-
sion. Lead is not easily biodegradable and is a hazardous heavy metal to human
health (Abdelwahab, 2015). The wastewater from industries such as electroplating,
metallurgy, paint, electronics, petroleum refining, and storage battery contains high