New Delhi: Researchers at BITS Pilani’s Hyderabad campus have found a way to use high-voltage electrical pulses to purify biopharmaceutical wastewater and turn it into reusable water and biogas.
The technology, titled ‘Voltage-Assisted Inactivation of Bacteria in Wastewater (VAIBaW)’, was developed at the BITS Environmental Science and Technology (BEST) lab by professor Sankar Ganesh Palani, professor Mithun Mondal, and research scholar Ravindra Dnyanaba Kulal.
“Conventional treatment of biopharmaceutical wastewater consumes large amounts of chemicals and thermal energy. Our approach shows it is possible to safely disinfect this complex wastewater using electrical pulses while recovering valuable resources including reusable water and clean energy,” Palani told ThePrint.
Such technology could prove to be a major breakthrough since India’s biopharma and biomedical industry is valued at over $58 billion as of 2024. Its bioeconomy contributes 4.25 per cent of the national GDP. India is also a top global supplier of vaccines. India is also a top global supplier of vaccines. VAIBaW could help ensure that as biopharmaceutical manufacturing capacity rises in India, the country also has a clean way of addressing biopharmaceutical waste.
Unlike many technologies that lie dormant in labs, VAIBaW is already in the process of being scaled up by the team in collaboration with Biological E, a Hyderabad-based biopharmaceutical and vaccine manufacturing company.
The researchers highlight that while space constraints are a big challenge when it comes to setting up wastewater treatment plants, VAIBaW won’t be hard to adopt. It doesn’t require manufacturing plants to be redesigned; all they have to do is plug in a replacement for the existing sterilisation system.
The challenge with biopharmaceutical wastewater
Biopharmaceutical medicines are produced using living cells, tissues, or microorganisms. The wastewater generated in the process is one of the hardest types of industrial waste to treat. It contains live microorganisms, residual antibiotics, and even genes that are antibiotic–resistant. Due to safety concerns, this wastewater cannot be disposed of before it is disinfected.
Currently, every batch of such water goes through a strong alkali chemical treatment and steam sterilisation. It is heated to around 120 degrees Celsius for nearly 90 minutes in a process called steam autoclaving and chemical disinfection.
“Usually they use the alkali chemicals such as NaOH or KOH, and while the impact of these chemicals might not be actually that critical, heating the waste water to a very high temperature for a longer period of time has a higher cost. More than the chemicals that are used to treat the wastewater, it’s the energy consumption that is the problem,” Palani said.
The researchers at BITS Pilani soon realised that extremely short bursts of high–voltage current could get the job done just as well.
Mondal added that Pulsed Electric Field (PEF) technology is already used by the food industry to kill off bacteria in juices and canned fruits. Several studies have documented its benefits.
The technology destroys harmful bacteria and yeast, but makes sure the juices still taste fresh. It also retains nutrients: vitamins and healthy antioxidants that can break down during pasteurisation are not affected by these electric pulses.
With VAIBaW, PEF technology will be used to treat biopharmaceutical wastewater for the first time.
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How controlled electricity disinfects wastewater
Mondal compares the high-voltage electrical pulses to tiny, controlled lightning strikes passing through wastewater. These puncture bacterial cells and kill them without even boiling the water.
His team’s new process has three steps. First, the PEF technology sterilises the wastewater. Then, 90 per cent of the organic pollutants are removed by microbes in a sequencing batch reactor, and the water is filtered. Finally, the remaining sludge is put into the patented Intelligently Stirred Thermophilic Anaerobic Reactor (iSTAR) and, instead of becoming waste, it produces methane-rich biogas, which can partially power the treatment plant itself.
“Imagine two electrodes. One is positive, another is negative, and between them, there is either air or water that acts as a conducting medium. When we pass high voltage through these electrodes, any microorganisms which are present between them will rupture, and the cell will die,” explained Mondal.
The professor said that the electric pulse lasts 1.2 microseconds and the voltage is nearly 300 kilovolts. They began with 900–kilovolt electric pulses to test for the ideal voltage and the perfect distance between the electrodes.
Experiments have shown that the pulses rupture bacterial cells and destroy nearly 99.9 per cent of bacterial contamination. This form of sterilisation is as efficient as steam autoclaving and uses significantly less energy.
“Through this technology, we could save up to 81 per cent of the operating cost compared to the steam sterilisation process,” Palani said.
Mondal explained that although the voltage is high, the current is extremely low—in milliamperes—which keeps electricity consumption also low.
The team is now exploring whether the PEF system can be powered by solar energy, further reducing the overall energy footprint.
The researchers have filed an Indian patent for VAIBaW, while their research paper detailing the findings is currently under peer review. Although regulatory approvals are still pending, the team has already received calls from pharmaceutical companies looking to adopt the technology.
(Edited by Prasanna Bachchhav)