Principle of Fecal Discharge in Mobile Toilets

The principle of fecal discharge in mobile toilets mainly relies on biodegradation, physical sedimentation, and a combination of various technologies, with different treatment methods employed according to different types. Details are as follows:

I. Biodegradation-Dominated Type

1. Microbial Decomposition Mode
   By adding high-efficiency composite microbial flora to the septic tank, the enzymes secreted by the flora can accelerate the decomposition of organic macromolecules such as proteins, fats, and carbohydrates in feces into carbon dioxide, water, and inorganic salts. This process requires maintaining appropriate temperature, pH value, and oxygen supply. Usually, a ventilation system is used to provide oxygen and promote the activity of aerobic bacteria, achieving a reduction in fecal volume and elimination of odors.

2. Microbial Mobile Toilets
   Excrement enters a solid-liquid separation device through an automatically opening toilet bowl. After separation, the feces enter a fermentation tank and are mixed with initial ingredients, sawdust, and biological strains. Stirred by a screw propeller, they decompose into CO₂ and H₂O under the action of microorganisms, with a degradation rate of ≥99%. Urine, after filtration, enters a comprehensive treatment system and is converted into reclaimed water through aeration, evaporation, and decolorization processes, which is then used to flush the urinal again, forming a cycle.

II. Combination of Physical Sedimentation and Anaerobic Fermentation

Traditional Anaerobic Fermentation and Sedimentation Separation
After feces enter the septic tank, solid particles settle by gravity to form a sludge layer, grease floats to form a scum layer, and the middle layer is clarified sewage. In an oxygen-deficient environment, anaerobic bacteria decompose the sludge, producing biogas and stabilizing organic matter. Modern designs are equipped with odor-proof floor drains, water seals, and forced ventilation systems to prevent blockages and odor overflow. The gases are discharged at high altitude through pipes or treated by activated carbon adsorption before being released.

III. Special Technology Types

1. Water-Flush and Waterless-Flush Suction Types
   The water-flush type uses a water tank at the top to flush, and the bottom sewage tank collects excrement. The waterless-flush type directly receives excrement in the bottom sewage tank. Due to the limited capacity of the sewage tank, both require regular suction for treatment.

2. Circulating Water-Flush Type
   Equipped with intermittent aerobic and anaerobic treatment devices, biological strains are added, and biofilm technology is applied to accelerate the fermentation and decomposition of fecal sewage. It is then filtered and recycled for toilet flushing, achieving water reuse.

3. Dry Packaging Type
   Without a water-flush device, excrement is received by biodegradable plastic bags. A new bag is automatically replaced after each use, and the used bags are collected and transported to a treatment plant for disposal, avoiding sewage generation.

4. Foam Sealing Type
   Foam generated by a foaming liquid mixture covers the inside of the toilet bowl, replacing the flushing function. Compressed air is delivered through pipes to a foam activator, causing the foam to cover the toilet bowl through side channels. Only hand-washing water needs to be collected to meet the foaming water demand, resulting in no odor and water conservation.