Functional Diagram of Public Mobile Toilets

The functional design of public mobile toilets covers multiple aspects such as structural composition, type classification, internal facilities, and architectural design.

I. Structural Composition Public mobile toilets are generally composed of core components such as fecal sewage storage tanks (or disposal units), sanitary fixtures, walls, and water tanks. The fecal sewage storage tank is used to collect excreta, and some models are equipped with disposal units for preliminary purification. Sanitary fixtures include squat toilets, sit toilets, and urinals. The walls are made of lightweight, high-strength materials to ensure structural stability and ease of movement. The water tanks are divided into storage-type or circulating water supply types depending on the flushing method.

II. Type Classification They can be classified into four types based on sewage treatment methods:

1. Water-flush Type: Water is supplied from a water tank, and excreta are flushed away by water flow. Regular replenishment of clean water and sewage treatment are required.
2. Waterless Suction Type: It relies on a vacuum pump or negative pressure system to suction excreta into the storage tank without using water, making it suitable for water-scarce areas.
3. Circulating Water-flush Type: It is equipped with a sewage treatment unit that filters and purifies sewage for recycling, reducing water consumption.
4. Dry Packaging Type: It uses biodegradable plastic bags to package excreta without water flushing. The bags are replaced when full, highlighting environmental friendliness.

III. Internal Facilities Taking the mobile bus toilet as an example, its functional design focuses on humanization and diversity:

• Basic Facilities: It is equipped with 5 independent toilets and 1 toilet for special groups, including squat pits, independent toilet compartments, and urinals to meet different usage needs.
• Barrier-free Facilities: An electric wheelchair lift is designed for the disabled, and a baby care folding table is installed in the special toilet for the convenience of parents.
• Convenience Facilities: Air conditioners regulate temperature and humidity, USB charging ports provide charging services for electronic devices, handrails enhance safety, and some upgraded models also add a third toilet for families or those who need assistance in using the toilet.
• Extended Functions: For example, the mobile toilet on Century Avenue has added a "sanitation station" equipped with a refrigerator, shower room, and microwave oven to provide a rest place for sanitation workers.

IV. Architectural Design The architectural design of mobile toilets emphasizes practicality and aesthetics:

• Drawing Types: It includes elevation drawings, plan drawings, section drawings, roof drawings, etc., with detailed annotations of dimensions, materials, and structures.
• Environmental Harmony: The exterior color blends with the surrounding landscape to avoid a sense of incongrity.
• Mobility Convenience: It adopts a modular design for easy and quick installation, disassembly, and transportation, adapting to temporary events or emergency scenarios.