Two Air India cargo aircraft have landed in Bengaluru with 34,200kg of zeolite imported by the Defence Research and Development Organisation (DRDO) to make medical oxygen for treating Covid patients, an official said on Sunday."The two aircraft carrying zeolite from Rome arrived as the first consignment of the key component," a DRDO official told IANS here.Zeolites are 'molecular sieves' comprising silicon, aluminium , and oxygen among othersand are used as a raw material to make industrial and medical oxygen."The component will be used to make medical oxygen at Tata Advance Systems Ltd plant at Malur in Kolar, with the technology developed and transferred by DRDO," said the official, who did not want to be identified."Zeolite will be used as a molecular sieve in making purified oxygen in the plant, which adopts pressure swing adsorption technology developed by the DRDO," said the official.More consignments of the raw material are scheduled to land at the city airport this week from Italy and South Korea to generate oxygen, whose demand shot up exponentially for treating Covid patients amid the pandemic's second wave."The technology has been transferred to 5-6 companies for making medical oxygen on priority to meet the growing demand," added the official.DRDO developed the technology to generate oxygen onboard its fighter aircraft Tejas, which has been inducted by the Indian Air Force.