Indians discovered the virtues of cow urine centuries ago, a product revered in traditional practices, touted by academics and sold commercially, but Chinese scientists have now forged ahead through an electrochemical method to extract a fertiliser from it.

The scientists at Henan University in north-central China have devised a process that converts urea, a nitrogen-rich waste, into 100 per cent purity percarbamide, a derivative of urea, bypassing the need for complex purification steps and transforming waste into a valuable product.

Their process, showing the possibility of percarbamide extraction from human and other mammalian urine, represents a novel, potentially scalable strategy for large-scale wastewater treatment that offers both economic and environmental advantages to existing methods of urea fertiliser production.

“This is the first demonstration of an electrochemical route to get percarbamide from mammalian urine,” Peng Lv, a team member at Henan University, told The Telegraph via email. “It promises a replicable and scalable new paradigm for urine treatment in future cities and farms.”

An economic analysis suggests that the extraction of one metric tonne of percarbamide daily would require urine from 6,382 households or 3,800 cows, the Henan scientists said in a research paper published in the journal Nature Catalysis on Monday.

Sections of Indian scientists said the Henan team’s work contrasts with claims about cow urine’s myriad benefits by advocates of traditional medicine as well as members of India’s academic community, which often lack rigorous scientific evidence.

A video clip showing Indian Institute of Technology, Madras, director Veezinathan Kamakoti purportedly praising the medicinal value of cow urine at a “ghoshala event” last week has drawn sharp comments on social media platforms with critics accusing him of peddling pseudoscience.

A PTI report on Sunday said Kamakoti, while addressing the event on January 15, had said that cow urine had “anti-bacterial, anti-fungal and digestive properties”, and that it was useful as a medicine for conditions such as irritable bowel syndrome.

He made the remarks after underlining the importance of organic farming and the crucial role played by indigenous cattle breeds in agriculture and the economy, the PTI report said. Critics, however, have used the remarks to slam the Centre for promoting pseudoscience.

DMK leader T.K.S. Elangovan hit out at Kamakoti and alleged that the central government intends to “spoil” education in the country. Congress leader Karthi Chidambaram accused Kamakoti of “peddling pseudoscience”, saying it is “most unbecoming” for an IIT director.

An Indian scientist who has been tracking claims about cow urine coming from within the academic community said the paper by the Henan scientists described a technique to extract a useful chemical from urine.

The 2015 Nobel Prize for physiology and medicine went to Tu Youyou, a Chinese researcher, who had turned to ancient Chinese medical texts to find a traditional cure for malaria and extracted a compound called artemisinin that has saved millions of lives.

Her work involved applying modern scientific principles to probe ancient knowledge, said Aniket Sule, a scientist at the Homi Bhabha Centre for Science Education, Mumbai. “That kind of rigorous follow-up never happens with claims about cow urine,” he said.

The electrochemical route to percarbamide is an alternative to existing processes that involve high temperatures and pressures and are economically and environmentally unfriendly. “Percarbamide as a nitrogen fertiliser results in better growth for several crops compared to urea,” Lv said.