Onions and Garlic Help Clean Wastewater

Low-cost technology uses onions, garlic peels to remove heavy metals from industrial waste

By on December 18th, 2012 12:59 GMT

The International Journal of Environment and Pollution has recently witnessed the publication of a new study stating that removing heavy metals from industrial wastewater need not necessarily be a costly and difficult thing to do.

Quite the contrary: some onion and garlic peels would more than suffice, seeing how these vegetables can double as wastewater “cleaners.”

According to the specialists who investigated this issue, a dietary fiber known as inulin is part and parcel of the cellular make-up of both onions and garlic.

It was this dietary fiber that sparked the researchers' interest, seeing how it can supposedly bond with metal ions and thus help clean most of the heavy metals typically found in industrial wastewater.

“The chemical composition of onion and garlic wastes, suggests that they could have some potential as a biosorbent,” reads the study.

Interestingly enough, it seems that the onion and the garlic used in these laboratory-based experiments could later on be made to let go of the heavy metal they stored while being exposed to industrial waste.

As the researchers explain, “Once the metals are recovered, the biomass material, which is biodegradable, will cause no environmental damage and may be utilised as natural soil conditioners or fertilizer.”

Scientific American reports that the onions and the garlic used in this study were provided by the canning industry, and that all that researchers had to do was dry them and turn them into a fine powder and later on mix them with industrial wastewater from a factory in Delhi.

Apparently, it only took about half an hour before as much as 70% of the lead, the iron and the tin in said industrial runoff was successfully removed.

“This preliminary study concerning the adsorption capacities of onion and garlic wastes indicates great potential for the reduction of metal ions in wastewater,” the team of Indian researchers concluded.

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