Now, water purifying technique that uses fruit peels

An Indian-origin scientist has developed the world's first water purification technique that uses the peels of apples and tomatoes to remove different types of pollutants.
In a bid to make clean water available at low cost, Ramakrishna Mallampati, a PhD candidate at the National University of Singapore (NUS), experimented with water treatment techniques using materials that are easily available, and came up with novel ways to purify water using the peels of apples and tomatoes.
The research was conducted under the guidance of Associate Professor Suresh Valiyaveettil of the Department of Chemistry at the NUS Faculty of Science.
The team hopes that their water purification methods can benefit communities living in places where there is little electricity or resources to set up a water purification plant.

Many hazardous pollutants enter the water supply through many channels, including waste disposal, industry effluent release or rain water drainage.
Such pollutants need to be removed before the water can be consumed. However, most water purification technologies are not accessible to economically disadvantaged people around the world.

Ramakrishna evaluated the effectiveness of tomato peel as an adsorbent by using different pollutants. He also studied the structure of the tomato peels to assess their efficiency as biomaterials to remove toxic metal ions and organic pollutants from water.
In addition, factors such as the pH, nature and amount of adsorbent used for extraction were considered to establish the optimum conditions under which tomato peel could remove various pollutants from water.

His study revealed that tomato peels can effectively remove different contaminants in water, including dissolved organic and inorganic chemicals, dyes and pesticides, and they can also be used in large scale applications.
The results were published in the Royal Society of Chemistry journal RSC Advances last year.
In another recently published study in the American Chemical Society journal ACS Applied Materials & Interfaces, Ramakrishna explored the viability of using the peels of apples for water purification, as apple peels are easily available as biowaste from food processing industries and they are biodegradable.
Similar to tomato peels, apple peels can also remove a range of dissolved water pollutants through the adsorption process.

In order to enhance the ability of apple peels towards extraction of negatively charged pollutants, Ramakrishna immobilised naturally occurring zirconium oxides onto the surface of apple peels.
Zirconium loaded apple peels were found to be able to extract anions such as phosphate, arsenate, arsenite, and chromate ions from aqueous solutions.