Water quality and treatment engineers have come up with a novel and cost-efficient technique to monitor the water supplies and sources for contamination.
Feminine hygiene products are now being inserted into streams and sewers around Yorkshire, UK. That’s because researchers have discovered a novel ancillary usage of tampons. These products, it turns out, can effectively and cheaply sample water quality and offer a quick feedback about possibility of contaminants.
Modern towns and cities usually have two separate lines of sewers. A sanitary sewer collects everything you flush or rinse down the drain, and transports it to a sewage facility for treatment. Then there are storm sewers or overflow sewers that collect up rainwater and runoff from roofs, paved roads, and parking lots. Such water, clean but unfit for consumption, is directly emptied out in natural waterways like streams or rivers.
However, “Grey water” contamination is a commonly occurring and is an increasing problem — water from dishwashers, showers, and laundry that ends up in the storm sewer via incompetent plumbing or deliberate dumping. While grey water may sound harmless, multiple bacteria and a wide variety of fecal matter, apart from the gunk from your dishwasher, are present in it. Unfortunately, laundry water looks very similar to regular, if slightly less pristine, water. Hence it is visually impossible to detect if a stream is contaminated.
Scientists suggested inserting fiber optic cables, but is a very costly option costing up to $13 (9 £) per meter of sewer tested. Moreover their routine calibration and usage mandates trained personnel. However, tampons can now help to detect contamination, merely by insertion in the water.
Laundry water, the scientists noted contained “Optical Brighteners” or OBs that are used to make your clothes look white and fresh. Interestingly, they are quite sticky and glow under UV light. Tampons on the other hand are quite absorbent and can quickly latch onto the OBs.
To test the efficacy of the low-cost system, tampons were placed in 16 surface water sewers, using the handy attached string to secure them to bamboo poles. After 3 days, the tampons were retrieved and tested under UV light. As expected they successfully detected grey water contamination. The tampons helped in the determination of a positive and negative results. Most importantly, the total cost of sampling is an estimated 30 cents/tampon (20 pence/tampon), including the cost of the black light.
[Image Credit | Gwen Pearson, University of Sheffield]