Seashells: A Novel Way to Clean Lead Contaminated Water?

Have you ever eaten a lead battery? If you’re alive to read this, chances are, you haven’t. Lead acid battery factories in developing nations often leak waste into the environment or dump this waste straight into the ocean. Unfortunately, millions of people in developing country drink lead-contaminated water each year. Lead is an incredibly toxic substance and is said to be one of the prime factors that lead (no pun intended) to the fall of the Roman Empire

Considering that most contaminated areas are in poorer nations, an efficient and cost-effective solution is needed. Luckily, we have the answer, and it’s not the fancy chemical or strange organic molecule you may be thinking of.


Seashells, via

Seashells, via

Seashells are able to remove lead from water by swapping the lead ions with calcium ions. The end result is harmless lead-carbonate forming on the seashell and pure lead-free water. The best thing is, these shells are extremely efficient at purifying the water.

The equation for this reaction is: CaCO3 + 2H2O + Pb2+→ Ca(OH)2 + PbCO3 + 2H+

The calcium carbonate dissociates in water to form a weak base, and leaves the lead open to bond with the CO3 ions

Unlike expensive lead-removal methods such as reverse osmosis and distillation, removing lead ions with seashells is extremely cheap. Lead-contaminated areas are also usually located near oceans or lakes. Thus, seashells are always in abundance. With this method we can use waste (seashells) to remove waste (lead), leading to a much safer environment for both the aquatic species and for humans.