microPURESALT

What it does

This design filters microplastics from seawater during salt production using vernacular, low-tech materials. It preserves salt purity, boosts food safety, and supports small-scale salt farmers without disrupting traditional methods.

Your inspiration

The idea began after reading about microplastics in human blood, Mount Everest, and sea salt. Sea salt struck me - not just as a source of ingestion, but as an untouched opportunity for intervention. I was inspired by India's vernacular water filters and artisanal salt farming traditions. I envisioned a low-tech, affordable system that could empower small salt farmers and local makers alike. The goal was never to cleanse the entire ocean in one go - but to begin with a pinch of salt.

How it works

microPURESALT is a gravity-driven clay filtration system that uses layered natural materials to remove microplastics from seawater before salt crystallization. Water flows through gravel, sand, and a compact blend of organic fibers and farm-waste pellets, with each layer capturing finer contaminants. The terracotta vessel provides structure and promotes steady flow. Central columns and grooves guide the water, and optional ceramic tiles add an extra filtration step. The use of farm and craft waste not only avoids harmful chemical reactions with saltwater but also creates income opportunities for potters, organic farmers, and rural artisans—broadening the impact beyond salt farmers and into local green economies. The system is estimated to filter out 70–90% of microplastics based on material performance studies.

Design process

The design evolved through multiple concept directions before settling on a filtration system for the pre-evaporation stage. I explored different interventions from mesh-based separators to mobile filter crates but realized the most sustainable option needed to work passively, with minimal disruption. Inspired by traditional Indian 3-pot water filters, I studied vernacular salt farming practices and material behaviors. This led to a gravity-fed, layered system using gravel, sand, fibers, and farm-waste pellets each chosen for their ability to capture progressively finer particles. after ideation, exploration and flow diagrams to visualize material layering, water paths, and structural elements. The vessel chambers are grooved to slide into support rails, allowing easy assembly and replacement. A scaled terracotta prototype - Test Prototype V1.0 was built to simulate chamber structure, flow direction, and sealing between layers. While lab testing is pending, the current system is modular, open-source, and adaptable usable as a standalone vessel or integrated into salt pan channels. The process was grounded in field-relevant logic, affordability, and the ability to be built using local skills and tools.

How it is different

Unlike domestic or industrial filters, this system is purpose-built for sea salt farming—removing microplastics while preserving natural salt and minerals. It uses no electricity or synthetic membranes, relying on sand, terracotta, fiber, and farm waste—making it low-cost, sustainable, and culturally relevant. Designed to filter seawater before crystallization, it avoids disrupting traditional salt farming. Its modular, reusable layers are easy to maintain and adopt with minimal training. Estimated to remove up to 70% microplastics (based on material studies), it protects human health and enhances salt purity. It also creates new income opportunities for potters, organic farmers, and artisans—expanding impact into local green economies. A low-tech, vernacular solution where none existed before.

Future plans

plan to build full-scale working prototypes for lab and field testing, then collaborate with salt farmers to refine the design regionally. Performance will be documented, and pilot programs explored. Partnerships with local salt farming bodies, NGOs, and governments will support scaling. An open-source guide will help others localize and replicate the system globally turning small interventions into scalable, real-world impact.

Awards

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