GROSS WAYS TO SAVE THE WORLD

Eat a mushroom grown on your baby’s used nappies and drink your own sewage with it. Sounds foul? You might as well get used to the idea, as in the future, we will remove waste, produce food, ensure clean drinking water, and generate energy all in one cycle.

Lack of water forces us to recycle

The state of California is going through a period of drought, which is now in its fifth year. There and in other parts of the world, climate change has made water scarce, forcing both scientists and city planners to find alternative solutions to keep up a steady water supply.

One of the most obvious solutions is converting sewage into drinking water. The method is seriously considered in several places in California, where, according to calculations, purified sewage could supply eight million people – or about 20 % of the population – with clean drinking water. The technology is presently used on a smaller scale in some places in Texas.

A company, which is supported by the Bill & Melinda Gates Foundation, has developed the method further and built a plant known as the Omniprocessor, which purifies the sewage, generating power in the process.

The idea of drinking water which was flushed down the toilet a few hours earlier will seem disgusting to many people, but the water boasts the best imaginable quality, and the challenge of introducing the method in water supply is psychological rather than technological.

Valuable substances can be extracted from food waste

Every year, EU consumers throw out about 100 million t of food waste, of which most ends up in rubbish dumps, but the garbage contains usable substances that can be extracted, as the waste is broken down. At the US Colorado School of Mines, scientists have developed a method for extracting silicon and oxygen, the basic elements of glass, from rice, banana skin, and egg shells.

Using bacteria, food waste can be broken down into methane, that can be split into carbon and hydrogen. The carbon can produce graphite for electronics, and hydrogen can be used as fuel.

Bacteria in your clothes help you cool off

In the future, your sportswear may be full of bacteria already when you buy it. Scientists from the American Massachusetts Institute of Technology (MIT) have developed a new technology that uses a special bacterium to open and close vent holes in the clothes. The bacterium, which is printed onto the cloth, boasts a special quality: it reacts to changes in temperature and moisture level by expanding or contracting.

When you exercise and become sweaty, the bacteria expand, making small flaps in the cloth open. MIT cooperates with the New Balance sportswear maker to introduce the bacteriumfilled clothes to the market.

Urine could save your life

It is usually a bad idea to pee in your pants, but a new technology from Bristol BioEnergy Centre in the UK allows energy to be generated in the process. Scientists have developed special socks that contain microbial fuel cells, in which bacteria generate electricity by breaking down organic substances in the urine.

The small fuel cells can still only generate a very weak current, but the scientists imagine that people stranded in the wilderness could use their own urine to power a small transmitter, which can indicate their whereabouts.

Get your own mealworm farm in the kitchen

You can easily make healthy and eco-friendly meat in your own kitchen with an automatic mealworm farm.

If the growing population of the world is to be fed without putting the climate on the line, we will have to eat insects instead of beef. So, the Livin Farms company has developed a practical device that makes it easy to produce mealworms for your own consumption. The mealworm hive is a kitchen tabletop tower, in which the insects pass from tray to tray as they go through their different stages of life. En route, you only need to feed the creepy-crawlies kitchen scraps and oats, and after 8-9 weeks,
they are ready to eat. According to the manufacturer, the worms have a neutral and slightly nutty flavour.

Mealworms contain important proteins, which also exist in other meat, but they only require 10 % of the area required to produce the same quantity of beef.

Moreover, it only takes 2.2 kg of feed to produce 1 kg of mealworms, whereas it requires 10 kg to produce 1 kg of beef. Insects also drink less water and emit less CO² than cattle.

Tofu made of mealworms

Tofu is a high-protein food made of soy milk, and students from the US Cornell University have made tofu of mealworm proteins (known as C-fu). For about 0.5 kg of C-fu, 10,000 chopped and finely divided mealworms are required. Subsequently, the proteins are isolated and united in a block. A simple calculation demonstrates that two billion people’s protein requirements can be met by producing mealworms in an area corresponding to the Danish island of Lolland.

Animals are fed insects

Can't bring yourself to eat worms? There is alternative that could make the insects be consumed more easily. The South African company AgriProtein makes protein flour out of mealworms. The insect proteins can replace the fish and soy flour now used to feed chickens, pigs, fish, etc. In this way, large areas, which are now used to grow soy beans, can be used for other purposes, and over fishing is avoided.

Faeces is turned into gas and electricity

According to calculations from the United Nations University, all the faeces that ends up out in the open today could provide electricity for 18 million homes, if the energy in it were extracted, and so, all human faeces in the world would be worth millions of dollars.

The process that generates energy from faeces simply involves the addition of bacteria to the faeces in an oxygen-free environment, making the bacteria produce methane gas. Scientists from the Cranfield University in the UK have developed a high-tech solution in the shape of a waterless toilet that converts faeces and urine into water, ash, and power.

The waste passes through a nanomembrane, which separates water molecules. The water is clean enough for the washing of clothes and irrigation. The rest is burnt in the toilet, generating enough power for the purification, phone charging, etc. The residual product is ash, which can be used as fertiliser.

Our disgust is often irrational

Disgust is a feeling that exists in people throughout the world, and according to research, it is based on fear of infection. Evolutionarily speaking, it has been an advantage that we automatically do not like food and drinks that could make up a health risk. And the fear of infection is so deep-rooted that we sometimes refrain from eating something, though there is no rational danger, according to experiments made by psychologist Paul Rozin from the University of Pennsylvania.

Rozin introduced test subjects to a piece of chocolate which was shaped like faeces. The experiment showed that the participants considered it foul to eat the chocolate, though it was quite harmless. On the other hand, irrelevant circumstances may also sometimes change our minds in a positive direction.

Interviews made by Rozin show that we would be more than willing to drink purified sewage, if it had been stored in a tank for a few years or had been carried across long distances.

Mushrooms turn waste into food

Mushrooms live by breaking down organic material such as dead trees and animals, but the nourishing and tasty organisms would just as well consume plastic waste and even used diapers.

1. First, the plastic waste is subjected to ultraviolet light in a special chamber. The radiation will both make the plastic sterile and boost the breakdown process, making it easier for the mushroom to consume it.
2. Special ball-shaped ”fungipots” are placed in a controlled environment in a ”greenhouse”. Tweezers are used to place plastic in the pots. The balls consist of agar, starch, and glucose.
3. Fungus spores are grown in a special nutrient fluid, from which they are removed (using a pipette) and injected into the balls, that provide something to grow on and hold nutrition for the first stage of growth.
4. After a few weeks, the mushroom’s mycelium has broken down the plastic and formed a ball, so it is ready to be consumed. The hollow balls can be stuffed with minced meat or filled with gravy.

Mushrooms break down nappies

Scientists from the Universidad Autónoma Metropolitana (UAM) in Mexico have experimented with growing fungi on used nappies. The nappies contain cellulose, which is difficult to break down in nature, but makes up excellent nourishment for mushrooms. After 2-3 months, the diaper volume has been reduced by up to 80 %. The main purpose of the project has been to solve a waste problem, but the mushrooms contain lots of protein, fat, and vitamins and could be used as animal feed.
Don't worry: the nappies are sterilised first.

By Kristian Filrup  in "Science Illustrated", Australia, Issue 46, 6, October, 2016, excerpts pp. 50-55. Digitized, adapted and illustrated to be posted by Leopoldo Costa.