University of Sheffield engineers use tampons that shine in the dark when exposed to ultraviolet light to identify areas where wastewater from washing machines, baths and showers has polluted streams and rivers. They also pinpoint the source of the problem. Natural, untreated cotton in tampons can absorb chemicals used in detergents, shampoos, and toilet paper. Optic brighteners are chemicals that make whites whiter and colors brighter. They also show up in ultraviolet (ultraviolet), light just like glowing t-shirts at bars and clubs. The University of Sheffield’s Faculty of Engineering found that tampons can glow when UV light hits them if they are placed in water with even the smallest amount of detergent or sewage. Prof. David Lerner performing pollution testing. Image: University of Sheffield. They published the results in Water and Environment Journal (citations below). There are many types of pollution. Possible pollutants include light, chemicals, building debris, house/business waste and airborne particulates. Over 1 million homes may be traced by glowing tampons. Professor David Lerner is the study leader. He explained that more than one million houses have their wastewater incorrectly connected to the surface water network. This means their sewage is going into the river instead of being treated at a treatment facility. It’s difficult to see where it is occurring because the discharge is irregular and can’t be always seen with the naked eye. Also, existing tests are complicated and costly. “The biggest problem with finding cotton that doesn’t contain these chemicals is detecting sewage contamination by looking for optical brighteners. Tampons are an obvious solution because they don’t contain any chemicals. Although our new approach is unconventional, it’s inexpensive and works.” Scientists conducted laboratory tests to determine how much detergent was needed in water before the tampons began glowing. The optical brighteners that were absorbed by the Tampons appeared in solutions containing 0. 01 1 liter of detergent in water. This is 300 more concentrated than what one might expect from a surface water pipe. After being dipped into the solution for only five seconds, the tampons continued to glow under ultraviolet light for 30 days. A field trial was then conducted by Prof. Lerner with his colleagues. The team suspended the tampons in 16 different outlets, which ran into rivers and streams in Sheffield for three days. They then used UV light to test them. The tampons glow in nine of the surface water outlets, indicating that there is sewage pollution. Yorkshire Water assisted the researchers in locating the source of sewage. The researchers traced the pipes back to four of nine polluted outlets and inserted a tampon into each hole. The team was able to identify the areas where the sewage came from and identified the homes that needed further inspection. One area was identified by a visual inspection. It had a sink and soil stack that were both connected to the wrong drain. It is easier to use gloating tampons than to test for dye. Prof. Lerner stated that it is possible to identify the source of pollution by using dye tests. The grey line that lines the riverbed is sign of sewage fungus. Streams and rivers could also be contaminated by norovirus or other pathogens from waste water. Many households that have been wrongly connected do not know they are dumping their wastewater into an incorrect system. Once the issue is discovered, it can be fixed immediately. The UK has local authorities that can complete any work required and charge the homeowner. This power is rarely used. This study proved that the glowing-tampon technique works in field practice. Prof. Lerner plans to conduct a larger trial to identify all sources of pollution in Bradford Beck. The EPSCR funded the research. Citation: Dave Mark Chandler and David Nicholas Lerner, “A cost-effective method to identify polluted water outfalls and unconnected drainage.” Water and Environment Journal. Published 31 February, 2015. DOI: 10.1111/wej. 12112.
