portable wash stations

Because water used for hand washing is relatively easy to treat for reuse, engineers have built and tested a standalone hand-washing station for use in public places and developing countries that recycles, according to an article on the New Atlas website.

The system, called a biologically activated membrane bioreactor (BAMBi), runs water through a three-step filtration process before the next person uses it to wash.

An ultrafiltration membrane allows bacteria to build up as a biofilm that breaks down contaminants in the water.

Because the water alone wasn't nutritious enough for the bacteria to survive for long, the engineers added nitrogen and phosphorus to the soap at the station. That mix keeps the biofilm strong enough to remove almost all of the contaminants.

After the biofilm, the water passes through an activated carbon filter to remove any remaining organic matter.  Then salt is dissolved in the stored water and hit with an electrolytic cell to produce chlorine.

The end result is clean, odorless, colorless water that has fewer bacteria in it than most tap water. BAMBi has already been field tested, but will be tested again in South Africa in January 2019.

The system is is primarily designed for use in developing countries but could also be used in other venues — such as public bathrooms on passenger trains.

The engineers hope the system will be part of a range of sustainable, self-contained amenities for developing countries.

Read the full article.