In many homes in Bihar, in eastern India, water still comes from the well, from a pump, from an aquifer that seems the same as all the others. Transparent, normal, even reassuring to look at it in a bucket. The problem of arsenic lies right there: it often enters daily life without smell, without color, without an obvious scene that raises alarm. It is drunk, it is used for cooking, it ends up in the habits of families who in various rural areas have few real alternatives.
The World Health Organization recalls that inorganic arsenic is highly toxic and that the main threat to public health comes from contaminated groundwater. Prolonged exposure through water and food can promote skin lesions, tumors, cardiovascular diseases, diabetes and damage cognitive development in children. The guide value indicated for drinking water is 10 micrograms per litre, a threshold which in many contaminated areas remains difficult to guarantee continuously.
The work of Arpit Kumar and his younger brother Abhijeet Kumar began from this very concrete friction. They were still students when they began studying the problem of arsenic in Bihar’s groundwater as part of a school project linked to the National Children’s Science Congress. Then came years of experiments, laboratory tests, improvements, field attempts. No glossy startup imagery with colorful chairs and motivational slogans hanging on the wall. More than anything, a practical question: how to remove a dangerous contaminant from water using a simple, sustainable and manageable system even outside large urban centers.
The magnet in the tube
The technology developed is called METAL, an acronym for Molecular Magnetic Technology for Arsenic Removal. The main device is called MARU, i.e Magnetic Arsenic Removal Unit. In simple terms, contaminated water passes through a metal structure with neodymium magnets embedded in a steel body. During the transition, the system uses magnetic separation to retain the arsenic, without adding chemicals to the water.
The Navmarg Research & Innovation company presents MARU as a modular solution, adaptable to domestic, community, school and institutional uses. On its website it describes the system as scalable, low maintenance and designed to reduce the costs of treated water. The interesting part lies in the simplicity of use: fewer consumable components to replace, less waste sludge, less dependence on complex infrastructure. For a village, a school or a small distribution point, these details weigh almost as much as technical efficiency.
Over time the project left the perimeter of the school laboratory. Navmarg Research & Innovation was founded in 2023 and the work has garnered national recognition. Arpit Kumar, now a student of molecular physics at the Manipal Academy of Higher Education, received an award for innovation in water technology thanks to the magnetic separation-based system. The group works between Manipal and Patna and has carried out pilot installations in areas affected by arsenic contamination, including public schools and rural communities.
The numbers must be read with caution due to the data declared by the team: Navmarg claims to have already purified over 300 thousand liters of water and to have reached more than 4 thousand people; in another more recent company profile it speaks of over 6 thousand individuals reached. Among the installations mentioned there is also a 5 thousand liters per hour municipal plant in the Bhojpur district, also in Bihar. These are still small figures compared to the scale of the problem, of course. But they have an advantage: they move the invention from the brilliant story to the dirty test of real use.
The water must also be monitored
Arsenic contamination in India mainly affects alluvial areas and river basins such as the Ganges and Brahmaputra. Among the most cited states are Bihar, West Bengal, Assam, Uttar Pradesh and Punjab, with situations varying from district to district. This is also why a treatment technology alone is only enough up to a certain point: analysis, maintenance, updated data, trained personnel and systems that remain in operation after the initial enthusiasm are needed.
The group’s next step goes precisely in this direction. Navmarg is working on sensors capable of rapidly detecting arsenic and bacteria such as E. coli in water, with real-time estimates based on electrical properties. Artificial intelligence comes in as a support to recognize anomalies and predict maintenance interventions before the system stops. The technical part remains partly confidential, also for patent procedures, but the approach is clear: purify the water and better control when it becomes dangerous again.
In this field the most useful ideas often have a less spectacular appearance than we would expect. A few years ago, Mesopaper was also certified, a paper-based filter material designed to reduce arsenic and lead below the reference levels indicated by the EPA and WHO, which can be used in various domestic water treatment systems. There too, no science fiction: simple materials, lower costs, a technology that tries to enter where large systems arrive late or arrive poorly.
The story of METAL/MARU works because it holds together two levels that often travel separately: research and daily life. On the one hand there are neodymium magnets, steel, physical separation, sensors, algorithms. On the other hand, there are families filling a tank, children drinking at school, villages where maintenance must be possible even without a technical team always available. Innovation for drinking water becomes credible when it accepts this minute effort, that of filters to clean, checks to repeat, costs to keep low.
Arpit Kumar summed up the meaning of the project with a very clear image: the objective, he explained, was to pursue the impact rather than the myth of the unicorn startup and the best technology, in certain places, is the one that can really be used.
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