Mobile Portable Toilet Design

The design of mobile portable toilets can refer to the following key points, optimizing through practical cases and general principles:

I. Basic Structural Design

1. Main Frame
   Taking the modification of a water storage tank as an example, the tank body can be longitudinally split into two halves. The height of the tank body (about 1.8 - 2 meters) can be reinforced with wooden strips to form an independent space. Omni-directional wheels are installed at the bottom to achieve mobility. The wheels should be load-bearing (e.g., with a load capacity of ≥100 kg) to ensure stability.
   The wall materials can be light-weight plastic soft panels or fiberglass, which take into account both waterproofing and portability. The roof adopts a foldable design (e.g., canvas + metal frame) for easy volume compression during transportation.

2. Functional Zoning
   The interior needs to be divided into a toilet area and a washing area (if space allows). A drainage pipe is installed at the bottom of the toilet area and connected to an external sewage tank or septic tank. The washing area can integrate a simple sink, which is connected to the water storage device and a showerhead through a three-way pipe to achieve water resource recycling.

II. Material and Process Selection

1. Core Materials

   • Structural Materials: Fiberglass or high-density polyethylene (HDPE) are preferred. These materials are corrosion-resistant, lightweight (the density of fiberglass is about 1.8 g/cm³), and can be molded into one piece through molds, reducing joint gaps.
   • Sealing Materials: Sponge strips or rubber sealing strips need to be embedded at the joints between the door frame and the wall to prevent odor leakage. The drainage pipe joints adopt threaded connections + Teflon tape sealing to ensure no leakage.

2. Surface Treatment
   The outer wall is sprayed with waterproof paint (e.g., epoxy resin paint) to improve weather resistance. The inner wall uses antibacterial paint (e.g., paint containing silver ions) to inhibit bacterial growth.

III. Sewage Treatment System

1. Dry Flush Type
   Dry packing technology is adopted, where feces are collected in biodegradable plastic bags and replaced regularly. It is suitable for water-scarce areas but requires supporting garbage classification and treatment facilities.

2. Recirculating Flush Type
   A small-scale sewage treatment device (e.g., a biological filter) is set up. Organic matter is decomposed by microorganisms, and the purified water is used for flushing the toilet. Disinfectants (e.g., sodium hypochlorite) need to be added regularly to maintain water quality.

3. Direct Flush Type
   A sewage pipe is connected at the bottom and directly discharged into the municipal sewage network or a septic tank. A slope of ≥2% (i.e., a drop of 2 cm per meter) needs to be ensured to avoid blockage.

IV. Additional Function Optimization

1. Solar Power Supply
   Monocrystalline silicon solar panels (with a power of about 100 W) are integrated on the roof to supply power to LED lights or small exhaust fans. Lithium batteries (with a capacity of ≥20 Ah) are selected to meet the power demand for 3 days of cloudy and rainy weather.

2. Intelligent Monitoring
   A liquid level sensor is installed to monitor the capacity of the sewage tank, and a fullness reminder is sent to the management platform through an Internet of Things module (e.g., NB-IoT). Temperature and humidity sensors are set up inside to automatically start the exhaust fan to adjust the environment.

V. Adherence to Design Principles

1. Mobile Convenience: The overall weight is controlled within 200 kg, and it can be pushed by manpower or towed by a small vehicle.
2. Economic Durability: The manufacturing cost of a single unit is controlled within 3000 yuan, and the service life is ≥5 years.
3. Environmental Ecology: Recyclable materials are preferred to reduce the impact on the environment.