Local Application of Mobile Toilets

The application of mobile toilets in the Shaoxing area primarily revolves around the public health needs of temporary gathering events, with equipment design, classification systems, and operational processes all needing to adapt to the region's topographical and hydrological characteristics as well as the requirements for ancient city preservation.

1. Constraints of Topography and Hydrology on Equipment Design

Shaoxing is characterized by a dense network of rivers and well-developed water systems, necessitating strict anti-leakage designs for mobile toilets. The bottom of the equipment typically employs a high-density polyethylene (HDPE) anti-seepage layer, combined with a double-layer structure or sealing strips, to prevent sewage from infiltrating the ground and contaminating water bodies. Additionally, the ground bearing capacity in the ancient city's protected areas is limited, requiring lightweight solutions for equipment transportation and installation. For example, aluminum alloy frames are used instead of traditional steel structures, with the weight of each unit controlled to within 2 tons. Modular design enables rapid assembly and disassembly, minimizing disturbances to the foundations of ancient buildings.

2. Equipment Classification and Treatment Technologies

Mobile toilets in Shaoxing are classified into three categories based on treatment technologies:

1. Biodegradable Type: Utilizes microorganisms to decompose feces into harmless organic fertilizer, suitable for long-term event scenarios. The equipment is equipped with a built-in bacterial culture box, requiring regular addition of biological agents. The treatment cycle is approximately 7-15 days, with no sewage discharge.
2. Chemical Treatment Type: Achieves rapid purification by adding disinfectants and deodorizers, suitable for short-term, high-flow scenarios. Sewage is temporarily stored in sealed tanks and transported to treatment plants by specialized vehicles after the event, with a single treatment capacity of up to 500 person-times per day.
3. Vacuum Suction Type: Employs negative pressure technology to suction excreta into a collection tank, achieving a water-saving rate of over 90%, suitable for water-scarce areas or high-end events. The equipment requires a配套 (matching) vacuum pump and storage tank, with a single suction service capacity of over 2000 person-times.

3. Operational Processes and Visual Harmony

The leasing service covers systematic steps:

1. On-site Assessment: Determine the type and quantity of equipment based on the event scale, topographical conditions, and ancient city preservation requirements. For example, the biodegradable type is prioritized in the core area of the ancient city to avoid the impact of sewage transportation on the landscape.
2. Equipment Allocation: Select appropriate equipment based on the assessment results and coordinate transportation routes to avoid load-sensitive areas such as ancient bridges and stone-paved roads.
3. Installation and Maintenance: Use adjustable feet to adapt to uneven ground, install anti-slip pedals and barrier-free access. Clean the equipment 2-3 times daily during operation and regularly inspect the anti-seepage layer and seals.
4. Recovery and Disposal: Conduct thorough disinfection of the equipment after the event, dispose of sewage in accordance with environmental protection requirements, and classify and recycle solid waste.

To blend in with the ancient city's landscape, mobile toilets feature antique designs, such as grayish-blue color schemes, curved eaves roofs, and lattice windows. Some units also incorporate cultural display panels, transforming them into landscape nodes within temporary public spaces.