Water treatment options – with fruit peels!

Pure water

A PhD candidate at the National University of Singapore, Mr Ramakrishna Mallampati recently experimented with water treatment techniques by using materials that are easily available (like the peels of apples and tomatoes) to purify water.

Fruit Peels ?

One of the biggest problems we are facing in today’s age is the scarcity of clean water, whether it be due to drought, contamination or lack of proper technology to produce potable water. This has been a wide-spread problem and is not limited to one country or continent. Clean water is becoming more and more scare and the water treatment industry has their hands full with creating affordable options for developmentally challenged countries to have access to drinkable water.

The scarcity of clean water is expected to get worse in the future due to factors such as over usage, lack of conservation methods and the ever dwindling natural supply of clean water and this extends to countries with significant water resources. Many dangerous pollutants enter water supplies through many channels and these include waste disposal, industry effluent release or rain water drainage. These pollutants need to be removed before the water can be considered safe for consumption, but the costs of these treatments are not always accessible to the economically challenged countries mentioned earlier.

The water treatment industry is studying and producing more and more options for treating water as the challenges are increasing to develop robust water purification methods at low cost, with minimal energy consumption and reducing the amount of chemicals used in order to counter the negative impact these chemicals have on the surrounding environment. One new solution has recently caused quite a stir–the use of fruit peels to purify your water.

Let’s take a look.

A PhD candidate at the National University of Singapore, Mr Ramakrishna Mallampati recently experimented with water treatment techniques by using materials that are easily available (like the peels of apples and tomatoes) to purify water.

Tomatoes are the second most consumed vegetable in the world and the disposal of the tomato skin and its other fibrous materials is an economic waste for many food processing industries. Mr Mallampati’s study revealed that tomato peels can effectively remove different contaminants in water, including dissolved organic and inorganic chemicals, dyes and pesticides and can be used in large scale applications too.

The viability of using the peels of apples for water purification was also explored in this study, as apple peels are widely available as biowaste from food processing industries. These skins are also biodegradable and can also remove a range of dissolved water pollutants through the absorption process. Naturally occurring zirconium oxides were immobilised onto the surface of the apple peels in order to enhance the ability of the peels towards extraction of negatively charged pollutants. Zirconium loaded apple peels were found to be able to extract anions such as phosphate, arsenate, arsenite and chromate ions from aqueous solutions. This method can also be applied to large scale applications.

When he was asked why he chose to experiment with these two particular edibles, Mallampati told Eco-Business: “In the quest of developing single adsorbent for all pollutants in water, we thought easily available and low cost biowaste will be efficient materials. We can use these peels for any kind of water but small modifications may require, if necessary.”

He continues: “[The water treatment] works based on the adsorption process. The functional groups of chemical compounds in these peels adsorb different pollutants. The adsorption process may involve a combination of ligand exchange, complex formation and electrostatic attraction processes. Adding peels to water works to reduce contaminants, but complete elimination of all pollutants depends on different parameters including concentration and chemical nature of the pollutants.”

These findings are hoped to benefit economically and technologically disadvantages farmers living in remote areas who depend on contaminated water from boreholes or local rivers for their daily water needs. It is also worth mentioning that this is the first time that the peels of two fruits have been used to successfully remove different types of pollutants in water.