In an effort to provide a new housing solution for low-income individuals, researchers in Japan have developed a novel housing structure.
They're using recycled diapers, replacing some of the sand, to construct the house.
Researchers believe this is a remarkably eco-friendly and innovative idea, as diapers have become one of the most troublesome waste items.
Diaper waste mainly comes from households with babies and care facilities for the elderly.
According to Japanese media reports, the amount of diaper waste has been increasing, reaching 2 million tons in 2015 and 2.2 million tons by 2020.
Based on statistics from the United States in 2018, the country disposes of 4.1 million tons of diapers annually.
I found that China's annual diaper waste has also exceeded 2 million tons.
For those who have raised children, these numbers hit home.
During infancy, a baby uses at least five to six diapers a day. If you can't predict the baby's schedule, using over a dozen diapers a day is not uncommon. Plus, a child typically needs diapers for 1-2 years. Just diapers alone can be a significant expense.
Processed Diapers
Diaper waste is not only abundant but also difficult to manage.
Typically, there are two ways to handle diaper waste: incineration or landfilling.
However, regardless of the chosen method, there are significant environmental impacts.
Incineration generates a large amount of harmful gases, and due to the high moisture content of soiled diapers, it can easily damage incinerators. Moreover, the main components of diapers, such as cotton, wood pulp, polyester, polyethylene, and polypropylene, are difficult to degrade in nature. Landfilling simply involves piling up waste without any real benefit.
Therefore, for environmental reasons, researchers at Kyushu University in Japan decided to recycle diapers to build houses.
This research team is not just about theories; they actually built a 36-square-meter single-story diaper house in Indonesia.
Are Diaper Concrete Houses Secure?
To test this notion, researchers began collecting used dirty diapers, cleaning them to remove solid waste, neutralizing any "harmful components" with chemicals, then bleaching, drying, shredding, and finally mixing them into concrete.
Samples were then allowed to cure for 28 days before being subjected to load tests.
Based on the results, the maximum allowable diaper-to-concrete ratio was calculated to meet safety standards.
Six different diaper-to-concrete ratios were tested, with the research team concluding:
Overall, the more diapers added, the lower the load-bearing capacity, but within certain limits, this material meets safety standards.
If it's a single-story house, diapers can account for up to 27% of the materials used; for a three-story structure, this proportion drops to 10%; and for non-load-bearing walls and floors, it can be relaxed to 40%.
In the "model houses" built in Indonesia, which are single-story structures, the proportion of diapers used is 8%. For a 36-square-meter house, approximately 200 pieces of diapers were used in total.
After testing, the research team found their idea to be entirely feasible.
Next, they will also test the soundproofing and insulation of the houses to see if they are suitable for human habitation.
On May 18, 2023, the research team published their findings in Scientific Reports.
Out of touch: Recycling diapers is more expensive
At first glance, it might seem like a good idea to recycle diapers to tackle the issue of diaper waste. By using them to build houses, they serve a dual purpose, reducing waste and cutting down on construction costs by replacing some sand with diaper material. It sounds like a promising project.
However, upon closer examination, this idea appears to be out of touch with reality.
The concept relies on the assumption that diaper recycling is free, when in fact, it's not only not free but also very costly!
According to the Japan Times, Japan is facing an increasing amount of diaper waste, primarily due to its aging population.
Nowadays, the main users of diapers are shifting from children to the elderly.
In recent years, the proportion of diaper waste has risen from 4.5% to 5.3% (of household waste).
This has prompted Japan to implement diaper recycling, with the city of Hachioji in Tokyo being one of the pioneers, but the results have been less than stellar.
Diaper Recycling
The city's waste management official remarked: "It's better off just incinerating them!"
Regular garbage disposal costs only 35 Japanese yen per kilogram (approximately 1.64 Chinese yuan per kilogram), but the cost of recycling diapers ranges from 40 to 90 Japanese yen per kilogram (approximately 1.87 to 4.21 Chinese yuan per kilogram).
In comparison, the cost of incineration is lower.
If you're unsure about these price levels, you can look at the garbage disposal fees in Zhejiang Province. The highest fee for processing 1 ton of household waste is 360 yuan, which equates to 0.36 yuan per kilogram.
In the end
Despite the current challenges in implementation, the Japanese have not given up on recycling diapers and have achieved some preliminary success after several years.
In April 2024, just this month, Japan introduced the concept of "horizontal recycling" with the launch of recycled paper diapers, produced by Unicharm.
After stringent processing, the recycled diapers are remade into new ones. According to health authorities, these recycled paper diapers meet safety standards.
They are now fully available on the market, priced at 1078 yen per pack (approximately 50.4 yuan), containing 42 pieces, which is more expensive than conventional products.
However, I think these diapers wouldn't sell well in our country. The high price isn't the main issue; it's more about the psychological aversion!
