Hyderabad: A waterless urinal at the metro stations is another facility that was added. In a first of its kind initiative, the Hyderabad Metro Rail and SGP waste water managers collaborated to convert urine into safe water.
HMR to install waterless urinals at Metro Stations
The biofilter technology is based on eco technology principle. In this unit the microbial culture and media is led down in appropriate manner for drop to drop filtration of urine. The main principle of this system is symbiotic relationship between plants and microbes. The ammonical nitrogen from the system is broken down by microbial strain in which ammonia and nitrogen is separated.
The nitrogen is used as nutrient source by plants and ammonia is taken up by microbes, then they liberate enzymes which maintain pH. The fungus and algae make thin film around grit in this system. This will also help to utilize remaining free nitrogen. Thus urine becomes odourless, colorless. The color is absorbed by thin film developed around grit and then is utilized by plants to grow. In same manner solids in urine are absorbed by thin film and utilized by plants.