Water scarcity and the need for potable water
Water is a crucial resource for all living organisms, and the scarcity of clean and safe drinking water is a growing concern globally. According to the World Health Organization (WHO), around 2.2 billion people lack access to safe drinking water, and around 829,000 people die each year due to inadequate water, sanitation, and hygiene. To tackle this issue, the process of transforming sea or river water into potable water has gained immense importance over the years.
Source of Potable Water: Sea or River Water
Sea or river water is the most abundant natural source of water on earth. However, the direct consumption of such water is not recommended as it contains impurities, microorganisms, and other particles harmful to human health. Potable water is obtained by treating seawater or river water through various processes that remove impurities and make it safe for consumption.
Stage 1: Pre-Treatment
Pre-treatment involves removing large particles and debris such as leaves, twigs, and rocks from the source water. This is done through a process called screening, where water is passed through a screen to remove large particles.
Stage 2: Coagulation and Flocculation
Coagulation and flocculation are chemical processes that involve adding chemicals to the water to remove smaller impurities that cannot be removed through screening. Chemicals such as aluminum sulfate and polyelectrolytes are added, causing impurities to clump together and form larger particles called flocs.
Stage 3: Sedimentation
The flocs formed in the previous stage settle to the bottom of the water tank due to gravity, forming a layer of sediment. This process is called sedimentation, and it removes impurities such as dirt, metals, and other particles.
Stage 4: Filtration
Filtration involves passing water through various filters that remove remaining impurities such as bacteria, viruses, and other microorganisms. The filters may include sand, gravel, and activated carbon.
Stage 5: Disinfection
Disinfection is the final stage of the process, where chlorine or other disinfectants are added to kill any remaining bacteria or viruses. This ensures that the water is safe for consumption.
Stage 6: Post-Treatment
Post-treatment involves adding fluoride to the water to prevent tooth decay and adjusting the pH level to make it safe for consumption. The water is then stored in a tank or transported through pipelines to homes and communities.
Potable Water Quality Standards
Potable water must meet certain quality standards to be considered safe for consumption. These standards include the absence of harmful microorganisms and chemicals, a specific pH level, and acceptable levels of dissolved solids.
Challenges in the Process
The process of transforming sea or river water into potable water has several challenges such as the high cost of treatment, the need for skilled personnel, and the disposal of waste generated during the process. Moreover, the increasing effects of climate change have made water treatment more difficult due to the changing chemical composition of the source water.
Conclusion: Importance of Access to Potable Water
Access to clean and safe drinking water is a basic human right, and the process of transforming sea or river water into potable water has made it possible to provide safe drinking water to millions of people. However, the challenges in the process must be addressed to ensure that everyone has access to safe drinking water.
References and Further Reading
- WHO. (2021). Drinking-water. Retrieved from https://www.who.int/news-room/fact-sheets/detail/drinking-water
- EPA. (2021). How is drinking water treated? Retrieved from
- WaterWorld. (2021). Challenges facing water treatment plants. Retrieved from https://www.waterworld.com/international/drinking-water/article/16201329/challenges-facing-water-treatment-plants