Mobile Toilet Odor Control

Odor control in mobile toilets requires a comprehensive approach combining ventilation design and deodorization techniques. The specific solutions are as follows:

1. Ventilation System Optimization

Ventilation is the foundation of odor control, relying on a dual-mode system of "natural air intake + mechanical exhaust" to achieve efficient air circulation.

• Natural Air Intake Design: The air intake is located at the bottom of the toilet, with an area of ≥0.05㎡. It utilizes air density differences to create an upward airflow, facilitating the expulsion of odors.
• Mechanical Exhaust Enhancement: A roof-mounted exhaust fan with a capacity of ≥300m³/h is installed to expel odors through negative pressure, ensuring indoor air is replaced 3-5 times per hour.
• Pipe Anti-Backflow Design: The exhaust pipe features a U-shaped bend to prevent odor backflow. An activated carbon filter (with an adsorption efficiency of ≥90%) is installed at the outlet to further purify the emitted gases.

2. Deodorization Technique Classification and Application

Depending on the odor components and scenario requirements, physical, chemical, biological, or comprehensive deodorization methods can be selected.

1. Physical Deodorization Methods

• Ventilation and Air Exchange: Through exhaust fans or natural ventilation systems, air is exchanged at least 10 times per hour to rapidly reduce odor concentration.
• Activated Carbon Adsorption: High iodine value (≥1000mg/g) activated carbon is used, with 1-2kg placed per cubic meter of space. It is replaced monthly to efficiently adsorb molecules such as hydrogen sulfide and ammonia.

2. Chemical Deodorization Methods

• Oxidizing Deodorizers: Solutions like chlorine dioxide (ClO₂) (concentration 0.1-0.3ppm) are sprayed every 4 hours to decompose mercaptans and amines.
• Masking Deodorizers: Plant essential oil formulations containing limonene or citronellol are suitable for temporary locations, with a duration of approximately 2-3 hours.
• Plant Extract Deodorization: Natural plant extracts are sprayed through atomization devices to neutralize odor molecules and generate odorless substances, with a single spray lasting 4-6 hours.
• Photocatalytic Decomposition: Titanium dioxide (TiO₂) generates highly oxidizing free radicals under ultraviolet light, achieving a deodorization efficiency of over 95% with a filter lifespan exceeding 5 years.

3. Biological Deodorization Methods

• Composite Microbial Agents: Agents containing Bacillus subtilis (≥1×10⁸CFU/g) and nitrifying bacteria are added at a rate of 50g per 10L of excreta, achieving a decomposition efficiency of over 90%.
• Biological Enzyme Deodorization System: A fixed-bed enzyme reactor continuously treats exhaust gases, achieving an ammonia removal rate of over 85% with an operating cost of approximately 0.5 yuan per cubic meter.

4. Comprehensive Deodorization Solutions

• Three-Stage Treatment System: Combines physical filtration (PP cotton + activated carbon), chemical oxidation (UV photocatalysis), and biological degradation to achieve a deodorization efficiency of ≥95%.
• Intelligent Control System: An ammonia sensor (detection range 0-100ppm) is linked to a spray device, automatically triggering the deodorization program when the concentration exceeds 20ppm.