The team, led by Ramakrishna Mallampati, found that tomato and apple peels act like a sponge in polluted water and help in "vastly reducing levels of heavy metals, pesticides and dyes", the Straits Times reported Thursday.
The two-year study showed that the peel of eight tomatoes can remove heavy metal ions such as lead from a litre of water within a period of one hour.
The findings can help nearly 800 million people without access to clean water to get safer drinking water at a low cost.
According to Mallampati, an alumnus of India's University of Pune, the results can help a vast number of people living in remote areas without access to water purification devices and people living in villages with groundwater contaminated by industrial pollution.
Mallampati, a researcher in material chemistry, is doing his Ph.D in the NUS on "synthesis and characterisation of novel materials for potential applications including water treatment and catalysis".