When I visited the famed underground cistern of Istanbul, which once provided a constant water supply for a massive palace, I noted that fish swam around in the water to “reduce bacteria”. Of course we’ve all owned algae eating fish at one point or another that kept our goldfish tanks clean, but these were massive fish that took the form of catfish or maybe even koi. After much wonderment I had the chance to look further into this method of decontamination myself. It turns out that even scientists debate the effectiveness of using fish to clean water. With a little reading I discovered that fish might consume algae in reservoirs in developing countries, but they certainly don’t purify water enough to drink it. Fish catalyze a reaction that reduces ammonia from rain water, making the water more suitable for life but not quite drinkable. Frankly, it sounds like an experiment I’d really love to try. You can read more about fish and their capabilities to clean water online. Here is the link to a discussion forum for this topic.
Kataka Seed. What is it? It comes from the Clearing Nut Tree and is sometimes used in India as a coagulant. What does that all mean? Coagulation can be compared to ion solvation in water. Essentially, the coagulant will bond to the suspended particles in the water that cause it to be muddy, and settle out the particles at the bottom of the water, allowing the clean water to be taken from the top. There’s a lot of existing research on this because the method of using crushed Kataka seeds to line water pots and other containers has been around since the dawn of written text. Here is a link on more reading.
Lima, Peru is said to have nearly one hundred percent humidity. That means that this major city located in a desert with less than one inch of rain per year has air that is completely saturated on the most humid days. Still, over 18 percent of the Peruvian population lacks safe water, and around 32 percent are not equipped with modern day sanitation.
Using inverse osmosis filtration and electricity, the University of Engineering and Tech of Peru developed a billboard that filters, condenses, and cleans water from air. The billboard can produce almost 100L of clean water per day. I hope that soon all billboards in Peru have this feature, and that the plans for building and modeling similar products are released!