Tiny Plants Clean Millions of Liters of Wastewater Daily

Dr Prasanna Jogdeo fell in love with the world's smallest flowering plant during graduate school in England, and that fascination just cleaned millions of liters of polluted water across India.

Duckweed looks like tiny green specks floating on pond surfaces, but this humble plant packs serious cleaning power. It sucks up pollutants through its roots, grows incredibly fast (doubling every two to four days), and converts toxic nutrients into harmless protein.

When Jogdeo returned to Pune in 2010 to teach at Fergusson College, he introduced his student Pooja Tendulkar to these remarkable plants. Their shared excitement led to years of research and countless conversations, even while Jogdeo pursued his PhD in Singapore from 2013 to 2017.

In 2018, the pair launched Lemnion Green Solutions, named after the duckweed family Lemnaceae. The startup doesn't just treat wastewater; it brings entire rivers and streams back to life using nature-based solutions.

Lemnion has now completed 30 projects across Maharashtra, treating wastewater systems ranging from 1,000 to 3 million liters daily. They've also rejuvenated polluted river stretches from 100 to 2,000 meters long.

The process is surprisingly simple. Duckweed cultures sourced from local water bodies are placed in treatment systems where water sits for about four days. The plants cover the entire surface, absorbing nutrients and pollutants as they grow.

Every two weeks, workers remove about 75% of the duckweed, which now contains up to 40% protein (similar to soybeans). This harvested material becomes garden fertilizer, completing a natural cycle that turns pollution into plant food.

The Ripple Effect

What started as one scientist's curiosity about a tiny plant is now changing how Indian cities think about water treatment. Lemnion works with businesses and governments to clean not just individual facilities but entire ecosystems.

The company doesn't rely on one-size-fits-all solutions. Instead, they've built a "proven toolkit" that adapts to each water body's unique challenges, whether it's a factory discharge system or a dying urban stream.

India has four or five duckweed species, each with special talents. Some grow incredibly fast, others excel at removing specific pollutants, and some serve as final "polishers" for nearly clean water.

Rivers that once ran black with pollution are returning to health, one floating plant at a time.