Technofile : Fragrant sludge

Sewage plants can smell sweeter thanks to a treatment developed by IBS
Viridian of Kent. It cuts the smell of hydrogen sulphide—the
characteristic stench of rotten eggs that is so offensive to people living near
sewage farms. A six-week trial carried out for West of Scotland Water found that
the company’s proprietary bacterial treatment, called VPHS, cuts the production
of hydrogen sulphide in sewage sludge by 90 per cent.