Page 24 - Materials Chemistry, Second Edition

Environmental and Health Effects Due to the Usage of Wastewater 5

concentrations of lead, and these industrial effluents, when released into nearby fresh
water sources, contaminate the water. The admissible levels of lead prescribed by the
United States Environmental Protection Agency (USEPA) and the Bureau of Indian
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Standards in water and wastewater are 0.015 and 0.1 mg L , respectively (Pandey
et al., 2015).
1.3.1.2 Mercury
Mercury is one of the most life-threatening heavy metal ions. USEPA has indexed
mercury as the most hazardous pollutant. It is highly lethal, and it is bioaccumulated
easily when it enters the food chain of human beings. Mercury is obtained in various
physical and chemical forms, among which mercuric ion is highly noxious. Mercury
ions are emitted into the environment from sources such as the mining industry,
the paper industry, the battery industry, the cement industry, power stations, and
so on. In addition, some natural activities and human activities also increase the
concentration of mercury ions in the environment. These mercury ions, even at trace
concentrations, can cause serious health hazards (Cunha et al., 2016; Rahman and
Singh, 2016; and Du et al., 2015). The desirable limit of mercury in drinking water
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is 0.001 mg L (IS 10500:1991).
1.3.1.3 Nickel
Nickel is an influential heavy metal in our present contemporary society. It serves
as the prime raw material in the production of steels, alloys, and battery industries,
which are all major industries contributing greatly to our country’s economy and
growth (Fukuzawa, 2012). Nickel is silvery white in color, and it exhibits sound resis-
tance even in highly alkaline conditions. It is ductile and malleable and possesses
good corrosion resistance. Nickel is emitted into the atmosphere by both natural and
human activities. Natural sources such as meteor showers, release from soil due to
decay, the combustion of woodlands, and so on are the major reasons for the emis-
sion of nickel into our environment, and humans also play a major role in increasing
nickel pollution by the burning of fossil fuels, the industrial production of nickel, the
incineration of community waste, emissions from transport, and so on (Kim et al.,
2014). The acceptable limit of nickel in drinking water according to the Bureau of
Indian Standards is 0.02 mg L (BIS IS 10500:2012).
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1.3.1.4 Cadmium
Cadmium is one of the most noxious heavy metals and is also a very big threat to
the personal wellbeing of human beings (Balaz et al., 2015). Cadmium has been
recorded as an extremely risky heavy metal by many organizations around the world
due to its high organic half-life of 10–30 years. Cadmium is a well-known mutagen,
which particularly affects the excretory system of human beings, and it is lethal to
other organs as well (Bilal, 2016). The manufacturing units of cement, batteries,
plastics, pesticides, pigments, dyes, and so on that release untreated effluents into
nearby water bodies are largely responsible for the increased cadmium concentration
in wastewater (Iqbala et al., 2016). According to the regulations of USEPA and the
European Union (EU), the allowable limit of cadmium in drinking water was set as
−1
0.5 mg L (Moinfar and Khayatian, 2017).