• 140 million people in 70+ countries drink water with unsafe arsenic levels.
• 1 in 3 children — up to 800 million globally — have high blood lead levels (≥ 5 µg/dL).
• Mercury exposure costs $117 B/year, causing 12M IQ-point losses and 29,000 deaths.
• India (2019) — contamination spotted in districts: Arsenic in 152 (21 States/UTs), Iron in 341 (27 States/UTs), Lead in 92 (14 States), Cadmium in 24 (9 States), Chromium in 29 (10 States).
• Odisha’s Sukinda Valley — chromite mining linked to > 84% of deaths in affected areas.

A field visit to our locality revealed alarming results!
At one location, Hg concentrations were 543 times higher than the CPCB–BIS Drinking Water Standard limits⤴︎ , while at another location, they were 895 times higher than the limit. Additionally, at a third location, Cr readings exceeded the safe limits and were significantly higher than the regulatory limit. Fe levels were slightly above the permissible limits but still within the maximum allowable range, and Al readings were also above the acceptable level yet remained within the maximum permissible limit.

Interacting with the people of Garampeta, and Daspur — coastal villages under Berhampur block, Odisha, India.

Our interaction with people of various ages, genders, and educational backgrounds, we found that the term Metal-Contaminated Water was largely unfamiliar.

When we mentioned Water Filter, most people referred either to the traditional candle stick filter or an RO filter, with little understanding of how these systems actually work.
Some even confused it with a hand pump!

Insights from our global perception survey also indicated that awareness of metal contamination scored 0.7 on a scale from -1 to 1.

Various regions globally have been widely identified as national sacrifice zones due to their prolonged exposure to severe environmental contamination, particularly from heavy metals. Sukinda Valley, India, stands as a prime example due to decades-long hexavalent chromium contamination. In Japan, the coastal city of Minamata became infamous for industrial mercury pollution, a crisis that has become a global case study. The U.K. witnessed its own tragedy in Camelford when a water treatment mishap led to aluminum sulfate contamination of the public supply. In the U.S., communities in Hinkley, California, have been subjected to hexavalent chromium in their groundwater, while Flint, Michigan, faced a devastating lead contamination crisis. These zones, each with its unique history of industrial and regulatory failure, underscore a global pattern where the health and well-being of a community are permanently compromised.

Meanwhile a multi-stage domestic water filter costs about INR 10,000 (around 113 USD). For many marginalized people, this is equal to or even more than their entire monthly income. On top of that, the routine maintenance adds another financial burden. This market is mostly covered by Reverse Osmosis (RO) filters, which are often combined with other technologies like UV (Ultraviolet) and UF (Ultrafiltration) to create multi-stage purification systems.
While other methods of water purification are available, they often leave residue of side products, while their efficiency to remove metal contaminant is unknown!

A sustainable, peptide-powered filtration system that captures toxic metals such as mercury, chromium, iron, and aluminum from contaminated water using bio-engineered peptides immobilized on biodegradable hydrogel beads. Unlike conventional treatments that require high energy, costly infrastructure, and struggle in mixed-metal or low-concentration conditions, POSEIDON is modular, reusable, and low-energy, making it ideal for decentralized purification. Designed with communities in mind, it offers an affordable, environmentally friendly, and scalable solution for safe water access—whether in rural villages, disaster zones, or industrial peripheries—bridging advanced synthetic biology with real-world impact.

At the heart of POSEIDON is a synthetic biology engine that brings molecular precision to water purification. Beginning with over 300 phytochelatin synthase (PCS) sequences, our team applied organism-wise clustering and multiple sequence alignment to distill the set into a panel of ~25 representative candidates. These were subjected to a two-tier docking workflow—first at the full-length enzyme, then at the catalytic N-terminal domain—to evaluate glutathione binding, catalytic geometry, and overall stability. From this, a PCS from Polyangium sorediatum emerged as a top choice, balancing docking energy, geometry, and expression feasibility. In parallel, a type-I wheat metallothionein (MT) scaffold was rationally engineered, adjusting cysteine clustering and local charge distribution to preferentially bind iron and aluminum, while retaining strong affinity for mercury and chromium. Both peptides were codon-optimized for expression in E. coli, purified with His-tags, and subsequently immobilized on alginate hydrogel beads using EDC/NHS coupling. This bead-based format ensures durability, biodegradability, and reusability, while eliminating the need for live organisms in the deployable device. To anticipate performance in real-world, multi-metal water streams, we implemented competitive Langmuir isotherm modeling, predicting how different metals compete for binding sites. This modeling informed optimal bead loading, packing density, breakthrough times, and regeneration strategies—projecting multiple adsorption–desorption cycles with >80% capacity retention. By combining high-throughput sequence mining, rational peptide engineering, and predictive dry-lab modeling with an accessible cartridge design, POSEIDON represents a leap beyond conventional water treatments: a biologically inspired, low-energy, community-centered solution to one of the most urgent global challenges—clean water for all.