World Water Day
Water covers 70% of our planet, and it is easy to think that it will always be available. However, freshwater—the stuff we drink, bathe in, irrigate our farm and industries fields with—is incredibly rare.
Only 3% of the world’s water is fresh water, and two-thirds of that is tucked away in frozen glaciers or otherwise unavailable for our use, so just 1% of available water can be used by us.
Today we are more than 7.7 billion people worldwide and each Portuguese individual spends an average of 187 litters of water per day. Depending on the geographical area where it resides, this value is higher if it is an urban area such as Porto and Lisbon. This average consumption value corresponds not only to domestic consumption but also to water spent on irrigating fields and industrial production. So, per day, considering that all people worldwide consume the same quantity, 1439.9 billion litters are needed to suppress their necessities. Think about it!
But, some 1.1 billion people worldwide lack access to water, and a total of 2.7 billion find water scarce in 2019. Inadequate sanitation is also a problem for 2.4 billion people—they are exposed to diseases, such as cholera and typhoid fever, and other water-borne illnesses. Water scarce is one of the most reasons of death.
In terms of numbers, just in 2016, Portugal spent about 700 500 000 000 litters of water, 74 % was consumed by agriculture and livestock, 20% by urban sector, 5% by industrial sector and 1% by tourism.
What do you think about water treatment? All drained waste water are treated and used again?
No! Only 60.1% of consumed water are discarded in waste water treatment plant (WWTP), of which 58.2% is treated. In turn, only 1.1% of these water is reusable and the remaining is discarded.
The reason is that wastewater treatments are not very efficient and final water is inappropriate for reuse, needing other treatments that are unavailable for all WWTP. Agriculture (pesticides), oil, textile and food industries are the most water’s polluting, and companies and researchers are working together to find new technologies. It includes modified membranes and activated charcoal to treat specifically these types of waters, not only in WWTP but also in the responsible industry – turning water more easily “reusable”.
Bio-solutions, it is possible?
Yes! Banana peels are an example of a bio-solution to treat wastewater, as a research group of University of Aveiro studied:
“Valuation of banana peels as an effective biosorbent for mercury removal under low environmental concentrations”
Researchers investigated the use of banana peels as bio-sorbent for mercury sorption from different aqueous solutions. Mercury is considered a heavy metal due to its toxicity when in contact with living organisms, and its ingestion can cause death.
The ability of banana peels to sorb mercury was also examined under seawater and a wastewater. Researchers could confirm that the bio-sorbent is efficient for mercury removal, and this way, it is a potential bio-solution for water treatment.
References
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