Low cost water purification using banana stalk

Access to clean drinking water remains a critical challenge. Commercial RO systems are expensive, require electricity, and waste significant amounts of water, making them unsuitable for many rural households.

Leveraging the natural porous structure and bio-absorbent properties of banana pseudo-stems—an abundant agricultural waste product—this project creates gravity-fed water purifiers that effectively remove heavy metals, turbidity, and certain bacteria.

The banana stalks are processed, dried, and treated to enhance their absorption capacity. They are then layered with natural sand and gravel within a simple terracotta or plastic housing. Water filters down naturally, requiring zero electricity.

Lab testing confirms the banana stalk filters reduce lead and copper concentrations by over 85% and significantly lower water turbidity. We are currently iterating the filter cartridge design to extend its functional lifespan before replacement.

This zero-energy purifier provides a virtually free, sustainable method for rural households to ensure safe drinking water, while simultaneously offering farmers a way to upcycle massive amounts of harvest waste.

The next step is establishing local micro-enterprises where village women are trained to process the banana stalks and assemble the filter cartridges for community distribution.