How Does a Composting Toilet Work?

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Composting toilets are becoming more and more popular, and not just with mobile homeowners. There are many advantages to using one, as well as a few disadvantages. Luckily, the disadvantages have almost nothing to do with unsanitary conditions or pricing.

But, it still begs the question. How does a composting toilet work? Here are the facts.

How Does Waste Turn to Compost?

Decomposition is a natural process by which waste is turned into fertilizer. For those of you that don’t know, human waste is roughly 90% water. That water gets released back into the atmosphere through evaporation and the remaining solid material then gets slowly converted into useful fertilizer.

But, is it really as simple as it sounds? Decomposition takes time and it also requires very specific environmental conditions in order to maximize the efficiency of the process. Because of this, a composting toilet has to boost a few steps in the decomposition process.

In more technical terms, composting is the transformation of human waste into fertilizer by microorganisms, under strictly controlled aerobic conditions.

The Three Operational Stages of a Composting Toilet

Without going into too much detail, know that there are three main requirements every composting toilet needs to fulfill:

  • Compost waste quickly without releasing odor
  • Produce a pathogen-free finished compost
  • Evaporate any remaining liquid

This is achieved through careful engineering and taking advantage of the environmental factors that affect natural composting. But, why is it important that all three criteria are met? Human waste can contain a lot of viruses, bacteria, and pathogens. In order to get a product that’s safe to use, the environment inside a composting toilet must assure the right conditions for bacterial breakdown.

Once that happens, viruses and pathogens will no longer be present in the compost. As a result, you’ll be able to use the compost on edible plants just like you use commercial compost, only with fewer health risks.

Do Different Toilets Have Different Composting Processes?

Yes. Composting toilet manufacturers are constantly trying to figure out new ways to increase the efficiency of the composting process. Therefore, you may find that no two composting toilets work in the same way.

With that said, there are some general guidelines that many manufacturers adhere to. Below you’ll find all the key info about the roles of the various chambers and parts inside a composting toilet.

Multiple Chambers

Every composting toilet should have multi-chamber design. There’s always the drum or large container that takes in your waste. Then, an evaporation chamber should be attached to it to allow the liquid to seep in. Lastly, a separate chamber is used to catch the finished compost. Sometimes, this chamber is made in the form of a pull-out drawer.

Moisture Control

Moisture control is essential for composting toilets. After years of research, most experts and manufacturers agree that the moisture levels shouldn’t drop under 40%. If they get over 60%, moisture can help drive out the oxygen faster which also helps drain excess liquid faster than it should.

Most toilets control moisture by applying indirect heat to the compost. Direct heat can dry it out and ruin the final product. Another way in which moisture control can be applied is by periodic mixing. You may have to do it manually in some cases, but most modern composting toilets do it automatically.

Managing Odors

All of the previously explained processes help guarantee odor-free operation. By maintaining warmth, turning the compost, and managing the moisture, the compost gets an even distribution of oxygen and moisture.

Even oxygenation is important because uneven oxygenation helps produce microbes which create foul odors and mess with the composting process.

What are the Differences Between Composting and Regular Toilets?

One of the biggest differences is that the composting toilets don’t flush. You can use various additives such as moss, sawdust, or coconut coir after each use. But, you don’t want to add extra water.

Another big difference is that a composting toilet will never be attached to or need a connection to a sewer system or a septic tank.

Finally, unlike a regular toilet, a composting toilet needs a lot more servicing of components. Keeping it clean, removing the finished compost regularly, and checking fans and chamber integrity are important maintenance tasks that you should be familiar with before you commit to a greener lifestyle.

Are You Ready to Go Green?

There’s no doubt that composting toilets work. But, what’s more important is to pick out a toilet that’s right for you and your needs.

Most people compost so that they can actually put the fertilizer to good use. However, an average household with a small garden or greenhouse will need a pretty big composting toilet. Keep that in mind when you start allocating space.

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