Mobile Toilet Emission Requirements
The emission requirements for mobile toilets cover multiple aspects, including sewage discharge, odor control, fecal waste treatment, anti-seepage prevention, pipeline design, compliance of discharge methods, and maintenance management. Details are as follows:
1. Sewage Discharge Standards
Sewage must be treated to meet standards before discharge or compliant removal. Conventional flush toilets need to be connected to municipal sewage networks or septic tanks. The sewage discharge limits must comply with the 'Integrated Wastewater Discharge Standard' (GB 8978-1996), setting limits for indicators such as Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), and Suspended Solids (SS). In scenarios without sewage network access, compliance with the zero-discharge special standard in HJ 1160-2021 'Technical Requirements for Environmental Labeling Products - Sewerless Sanitation Systems' is required, achieving zero sewage discharge through biodegradation or sewage storage tanks. The design of the sewage discharge system must comply with the 'Urban Public Toilet Design Standard' (CJJ 14-2016), ensuring reasonable pipeline slopes and sealed joints to prevent sewage retention or overflow.
2. Odor Pollutant Control
The concentration of odor gases must comply with national standards. Mobile toilets need to control the concentration of odor gases such as ammonia and hydrogen sulfide within the limits set by the 'Emission Standard for Odor Pollutants' (GB 14554-1993) through ventilation systems or deodorization technologies (e.g., activated carbon adsorption, photocatalytic oxidation). The ventilation system must ensure an air exchange rate of at least 6 times per hour, and deodorization devices must be installed at exhaust vents to prevent odor diffusion and impact on the surrounding environment.
3. Harmless Treatment of Fecal Waste
Fecal waste must be treated to meet harmless standards. According to the 'Hygienic Requirements for Harmless Treatment of Feces' (GB 7959-2012), fecal waste must be treated through methods such as high-temperature composting, chemical disinfection, or biodegradation to ensure a parasite egg mortality rate of at least 95% and a fecal coliform count of no more than 100 per gram, avoiding the risk of pathogen transmission.
4. Anti-Seepage and Groundwater Pollution Prevention
Strict anti-seepage measures are required for the toilet body, sewage storage tanks, and site. The overall structure must adopt a closed integrated design with a waterproof rating of at least IP65 (GB/T 42568-2023). The ground must have at least 3 layers of waterproof coating, and a 48-hour closed water test must show no leakage. The 24-hour leakage rate of sewage storage tanks/septic tanks must be no more than 0.1% (HJ 2029-2013). The toilet body must undergo double-layer anti-corrosion treatment inside and out, with an anti-corrosion layer lifespan of at least 10 years. The placement ground must be hardened and laid with an anti-seepage layer with a permeability coefficient of no more than 10⁻⁷ cm/s to prevent sewage from seeping into the groundwater.
5. Pipeline System Requirements
Pipelines must be corrosion-resistant and prevent backflow. Water supply and drainage pipelines must undergo corrosion-resistant, anti-condensation, and anti-leakage treatments, with joint sealing ratings of at least IP67. Backflow prevention devices (e.g., check valves) and water seal odor prevention devices must be installed, with a water seal depth of at least 50mm, complying with GB/T 17217-2021 requirements to prevent sewage backflow or odor reflux.
6. Compliance of Discharge Methods
Appropriate discharge methods must be selected based on the scenario. Conventional flush toilets need to be connected to water supply and drainage pipelines; vacuum sewage systems use negative pressure principles to efficiently collect sewage; water storage sewage systems are suitable for locations with sufficient water sources; biodegradation technologies achieve environmentally friendly discharge through microbial decomposition of organic matter. All methods must ensure that sewage is not directly discharged externally to avoid environmental pollution.
7. Maintenance and Management Requirements
Regular cleaning and water-saving measures must be implemented. Septic tanks need to be cleaned every 3-6 months to prevent blockages and odor generation. Water-saving toilets (e.g., foam-sealed or vacuum-suction types) should be used, with a single flush volume of no more than 0.5 liters. The use of reclaimed water technology is encouraged, where hand-washing water is used for toilet flushing to improve water resource utilization.
