Separating and dry toilets

Separating and dry toilets are becoming more and more popular. Dry toilets are increasingly being used, in particular by weekend and holiday home owners, or as a toilet solution in garden houses or allotments.

Even though these toilets do not require any water at all, no compromises in terms of hygiene are necessary: even without water or (toilet) chemicals, separating and dry toilets are not only particularly environmentally friendly, but also hygienic and odourless thanks to the way they function.

In this article we will explain what other advantages make the purchase of a separating or dry toilet attractive, how they work exactly, but also what disadvantages can arise in individual use cases.

Differences between dry toilets and separating toilets

Since the terms dry toilet and separating toilet are often used synonymously both in online forums and in colloquial speech, it is necessary at this point to clarify these terms.

What is a dry toilet?

Separating toilets are always dry toilets, with the exception of a few models that can also be operated with water. On the other hand, dry toilets are not necessarily separating toilets! All dry toilets, such as the compost toilet, are waterless toilet systems, but most do not separate the excreta. Dry toilets are therefore characterised above all by the fact that they do not require flushing with water and consequently do not need to be connected to a sewage system. They are therefore a waterless alternative to the conventional toilet, which at the same time relieves local sewage systems.

What is a separating toilet?

As the name suggests, it is the other way round with separating toilets. With the aid of a separating insert or separator, liquid is separated from solid waste and collected in a separate container. It is therefore a dry toilet with a separation system. Urine is fed into a container at the front, while faeces and toilet paper end up in a solids container in the rear area, where they are covered with litter after each toilet visit. This removes liquids from solid matter and at the same time prevents formation of unpleasant odours.

An electrical exhaust system can also be used for this purpose. Some systems, such as the TROBOLO TeraBlœm with electric exhaust system, work so efficiently that it eliminates any need for litter. Even just separating urine from faeces reduces odour formation to a minimum, as it is precisely the mixing of solid and liquid excreta that causes such odours in the first place. One of the main reasons for separating urine from faeces is therefore the prevention or minimisation of odours. Another reason is the easy disposal and further use of toilet waste as compost, which is made possible thanks to the separation process.

Functionality of a dry toilet with separation system

The separating or dry toilet has an appearance similar to a conventional toilet. However, it looks a bit different on the inside. Dry toilets with a separation system are based on the rather simple idea of collecting urine and faeces separately. This makes sense because faeces make up only about 10% of our excrements. Urine, if collected separately (yellow water), can be disposed of much more easily than when it is mixed with faeces (black water). Thanks to the separation procedure, considerably less toilet waste is produced, which needs to be composted or disposed of in the same manner as household waste, such as used diapers.

In order to ensure separation, a separator is used in dry toilets, which directs urine into a liquids container at the front; whereas faeces end up in the rear part of the toilet in a solids container, where they are collected without coming into contact with the container itself, thanks to the use of so-called inlays (collection bags). After the “business” has been completed, a quantity of litter is finally added to the solid precipitates in order to bind any residual liquids.

In some models with an electrical exhaust system, the use of litter is not necessary, as odours and moisture are reliably removed through ventilation. If you decide to use an electrical exhaust system, the user of litter is not necessary. Used toilet paper can also be placed directly in the collection container.

Usage of dry toilet with separation system

In spite of differences in functionality compared to conventional toilets, the user of a dry toilet with separation system will not need to do anything differently: separation of the excreta is contact-free and reliable. Direct bodily contact thus occurs – as with a normal toilet – exclusively at the toilet seat, while urine and faeces are separated behind the scenes by the integrated separator. The seating position is also identical to that of a conventional toilet. The only real difference is that it is best not to urinate while standing, since otherwise urine might end up in the rear solids container, which prevents clean separation of excreta.

Separating toilets and odours

Separation of solid and liquid precipitates also effectively prevents the main cause of odour formation. This is because unpleasant odours mostly arise when urine and faeces are mixed. As a result, moisture content of the mixture will be high, which has a catalysing effect on odour formation. In addition, ammonia, which is responsible for the majority of unpleasant odours, is formed during the rotting and decomposition processes of mixed excreta.

In order to consistently prevent the occurrence of odours, installation of an electrical exhaust air system is recommended. This channels residual odours and moisture to the outside via an exhaust duct. The exhaust air duct is installed either vertically at a height of about two metres, so that surrounding areas are not disturbed by odours, or horizontally directly through the outer wall, provided that there are no public areas directly behind it. An efficient exhaust air system completely prevents any residual odours from escaping the separating toilet and is more convenient than a conventional toilet in this respect.

Accessories, disposal and cleaning

As soon as the dry toilet with separation system is ready for use, in addition to litter which binds the faeces, only inlays for the solids container are needed to cleanly dispose of its contents. Depending on the disposal method, inlays made of plastic or biodegradable material, such as maize starch, can be used, which will then be disposed into a composter, along with its contents. However, it should be noted that compostable inlays have a limited shelf life and, like the solids themselves, decompose eventually, which is why it is advisable to change them on a weekly basis. Inlays made of plastic, on the other hand, have an unlimited shelf life and are therefore particularly suitable for longer intervals between disposals, which can be achieved with separation toilets that have an electrical exhaust system installed. Furthermore, the use of plastic inlays does not rule out composting the toilet waste, as it is much drier than one might expect. In this case, inlays and solids can easily be disposed of separately.

Thanks to inlays, cleaning of the solids container is kept to a minimum, as the precipitates never come into direct contact with it. After removing the inlays, cleanliness and hygiene of the solids container can be restored quickly and easily by occasionally wiping it with a damp cloth.

Disposal of precipitates in dry toilets with separation system

Disposal of the precipitates in dry toilets with separation system is problem-free and takes only a few steps, but may have to be performed in accordance with official guidelines. Urine can either be diluted with water and used as fertilizer or disposed of in a toilet connected to the main sewage system. Solid excreta can be disposed of – similar to diapers – in household waste if they are kept in plastic inlays, or in the organic waste bin if suitable bags are used.

However, it is important to enquiry with local authorities about proper disposal methods. Sometimes compostable inlays can cause problems in regional disposal stations or biogas plants, which is why this type of disposal is prohibited in many communities. For this reason, decentralised composting of biomaterial in one’s own garden is often recommended, which also respects the natural cycle of such materials. In any case, one should enquire in advance with local authorities as to the planned method of disposal.

Cleaning of dry toilets with separation system

Once urine and faeces have been disposed of, cleaning of a dry toilet with separation system can then be carried out in just a few steps and with minimal effort. As already mentioned, the two storage containers can be wiped off with a damp cloth if necessary. The hygienic maintenance of the outer components of the dry-separating toilet, such as the toilet seat, is also straightforward and can be carried out in a few simple steps. As with a conventional toilet, cleaning with a cloth and some cleaning agent is entirely sufficient.

Applications of dry toilets

he functionality of dry toilets opens up a wide range of applications. Since neither access to water mains nor a connection to the sewage system is required, a dry toilet can be installed and used almost anywhere. This flexibility and independence means that they are mostly used where the aforementioned utilities are either not present, or too difficult to access. These toilets can be used both indoors and outdoors. For example, gardens, golf courses, dog schools, riding stables or day-care centres are ideal locations for outdoor dry toilets. As for indoors applications, dry toilets are suitable for use in holiday homes, gazebos, caravans, mobile homes and boats.

Advantages and disadvantages at a glance

The particular advantages and disadvantages of using a dry toilet with separation system are illustrated as follows:

Advantages

• No water: No access to sewage systems is necessary
• Free of chemicals: The decomposition of urine and faeces takes place naturally and is not prevented by environmentally harmful additives
• Hygienic: No compromises in terms of hygiene compared to conventional toilets
• Environmentally friendly and easy disposal: Disposal essentially happens through normal household waste collection. Alternatively, faeces can be properly composted if required; urine diluted with water can be used as fertilizer
• Odourless: Separation of precipitates minimises formation of odours, an exhaust air system completely prevents them from occurring
• Autonomy: Non-reliance on local sewer systems and simple disposal of the precipitates guarantee the greatest possible independence

Disadvantages

• Accessories: For a biodegradable and uncomplicated disposal, special storage bags are required, provided you wish to dispose of them along with the excreta. Alternatively, the contents of storage bags can be composted, and plastic bags disposed of separately
• Electricity: Depending on the type of exhaust air system, an electricity connection is required

Conclusions for people interested in dry toilets with separation system

The above remarks show that dry toilets with a separation system are far more than just an alternative to conventional toilets, in cases where those cannot be operated, for example due to a lack of access to water. Dry toilets with a separation system are also odourless, do not contain any chemicals and are also extremely environmentally friendly due to their waterless operation, as well as the possibility of composting excreta. In addition, our TROBOLO dry toilets are made of high-quality and durable wood, and can be set up quickly and easily anywhere.