Mobile Toilet Meets Direct Discharge Standard

Achieving direct discharge standards for mobile toilets relies on an integrated waste treatment unit, which enables preliminary on-site treatment and compliant discharge of waste through solid-liquid separation, biodegradation, and disinfection.

I. Operational Mechanism

The core of direct discharge standards lies in the integrated operation of the waste treatment unit, which involves three main steps:

1. Solid-Liquid Separation: Solid waste is separated from liquid using mechanical screening devices (such as vibrating screens or rotating filters). The solid portion typically enters an independent collection container for regular removal, while the liquid proceeds to subsequent treatment stages. This step reduces the load on subsequent biological treatment and prevents solid particles from interfering with microbial activity.
2. Biodegradation: The liquid flows into a biological reaction zone, where specific microbial communities (such as aerobic or anaerobic bacteria) decompose organic matter. The reaction zone may employ membrane bioreactors (MBRs) or contact oxidation processes to convert pollutants like ammonia nitrogen and COD into harmless substances through microbial metabolism. For example, some mobile toilets use composite microbial agents that can reduce BOD₅ in wastewater by over 80% within 24 hours.
3. Disinfection Treatment: The final liquid undergoes disinfection (using methods such as ultraviolet light, ozone, or chlorine tablets) to kill pathogenic microorganisms, ensuring residual chlorine levels comply with the requirement of “fecal coliform count ≤ 1000 per liter” in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB 18918-2002). The disinfected water can be directly discharged into municipal sewage networks or specific containers.

II. Quality Standard Priorities

The direct discharge mode must meet two types of standards:

1. Water-Flush Direct Discharge Type: Requires a stable and water-saving flushing system, such as foot-pedal-activated flushing devices with a single flush volume of ≤3 liters to avoid water waste. Components must comply with the requirement of “flushing device durability ≥ 50,000 cycles” in the Portable Toilets standard (CJ/T 378-2011).
2. Overall Requirements: The treatment unit must be compact and efficient, integrating sensors for real-time monitoring of operational status (such as liquid level and flow rate), residual chlorine content, and water quality parameters (such as pH and COD). Data is transmitted via the Internet of Things to a management platform for fault alerts and proactive maintenance, reducing the frequency of passive removal operations.

III. Relevant Certifications and Implementation Standards

The production of mobile toilets must adhere to industry standards such as the Non-Flush Sanitary Toilets standard (GB/T 18092-2000) and the Portable Toilets standard (CJ/T 378-2011) to ensure structural safety, leak prevention, and environmental performance. The direct discharge system must also comply with local environmental protection authorities' specific requirements for wastewater discharge, such as the stipulation in some cities that wastewater from mobile toilets must meet the tertiary standard of the Integrated Wastewater Discharge Standard (GB 8978-1996) before discharge.