Page 21 - Materials Chemistry, Second Edition

2 Life Cycle Assessment of Wastewater Treatment

1.5.5 Decrement of Dissolved Oxygen ........................................................13
1.5.6 Persistent Organic Pollutants .............................................................. 14
1.6 Impacts of Wastewater on Public Health ........................................................ 14
1.6.1 Heavy Metal Poisoning....................................................................... 14
1.6.2 Impacts of Microbes ...........................................................................15
1.6.2.1 Diseases Caused by Bacteria ...............................................15
1.6.2.2 Diseases Caused by Viruses ................................................15
1.6.2.3 Diseases Caused by Parasites .............................................. 16
1.6.2.4 Effects of Agricultural Chemicals ....................................... 16
1.6.2.5 Effects of Endocrine Disrupters .......................................... 16
1.6.3 Effects of Dyes.................................................................................... 16
1.7 Case Study on Wastewater Effects on Humans .............................................. 16
1.8 Future Perspectives ......................................................................................... 17
1.9 Conclusion ...................................................................................................... 17
References ................................................................................................................ 18

1.1 INTRODUCTION

Water is one of the greatest gifts of nature, and it is the main source from which
energy is derived. All living beings in this world depend on water for their survival.
Life on earth would be impossible without water. Around 71% of the earth’s sur-
face is covered by water; however, around 98% of this water is useless because of
its salinity and cannot be used for drinking purposes. The rest of the earth’s water
is fresh but is not easily accessible, because out of this 2% of fresh water, around
1.6% is trapped in polar ice caps and glaciers. In addition, 0.36% of fresh water
resides in aquifers and wells. Thus, only 0.036% of water is available for drinking
purposes from rivers and lakes. According to a study conducted by the World Health
Organization/United Nations Children’s Fund (WHO/UNICEF), the collection of
fresh water from nearby water resources for drinking purposes is the highest-priority
household work of many women and children in nearly 45 developing countries.
People in these countries spend most of their time collecting fresh water instead
of attending school, going to work, or looking after their family. From this, we can
clearly understand that water has become an unaffordable commodity in our lives
today (Reddy and Lee, 2012).
Water scarcity and the quality of drinking water are among the most significant
issues that humankind is confronting in the twenty-first century (Naushad et al.,
2016; Alqadami et al., 2017). This water scarcity issue will be exacerbated by chang-
ing climatic conditions, which increase the temperature of water, leading to the melt-
ing of polar icecaps. As a result, an escalation of the hydrological cycle occurs, which
causes flash floods and dry spells. Furthermore, many people globally are seriously
affected through contaminated drinking water due to improper sanitary manage-
ment. In addition to this, other sources such as manufacturing industries, farmlands,
and municipal sources play a vital role in increasing water pollution. Water becomes
contaminated for various reasons, but the pollution due to chemicals is a major threat
globally because of its high toxicity; in many developing countries, nearly 1.1 billion
individuals are in need of safe drinking water, and 2.6 billion individuals do not have