A new chemical mix could kill the rotten egg stink emanating from sewer pipes, costing billions of dollars worldwide in odour control, says a study.
But is is not only a matter of minimising or eliminating bad smells. The gas hydrogen sulphide linked with the stink also plays a role in corroding sewer pipes, which is another costly problem, especially in warm climes.
Trials with a magic mix of chemicals, called Cloevis, on sewers in the Gold Coast region in Australia stopped 99 percent of the rotten egg gas or hydrogen sulphide emission from these pipes.
Zhiguo Yuan, professor at the University of Queensland, who led the study, told International Water Association (IWA) delegates that a week after dosing for a few hours, gas levels declined drastically. The results have been observed over five months.
“We are currently looking to commercialise Cloevis and are doing a further four trials of the mix in the US and Canada,” Yuan said. “Our partners over there are very excited by Cloevis’ potential.”
Yuan’s team, working with key members of Australia’s water industry, is also concentrating on corrosion issues and have done another study into chemical-free methods for managing hydrogen sulphide gas, according to a Queensland statement.
“We have done some trials with oxygenation of sewage using an electrochemical method which has reduced hydrogen sulphide enormously,” he says. “We probably won’t stop all bad smells from sewers forever but we’re well on the way to reducing their extent.”
The findings were presented at the 2012 International Water Association (IWA) conference this week.