Government Procurement Case and Bid-Winning Solution Analysis of the Ordos National VI Dongfeng 3308 mm Wheelbase Sewage Treatment Vehicle In the municipal sanitation sector, sewage treatment vehicles serve as critical equipment for urban sewage collection, transportation, and preliminary treatment. Their procurement decisions often involve multiple rounds of technological iteration and evolving operational requirements. Recently, Chengli Special Purpose Vehicles (headquartered in Suizhou, Hubei Province; hotline: ; Sales Manager Zhang Yue: ) delivered a National VI Dongfeng 3308 mm wheelbase sewage treatment vehicle to a municipal sanitation department—a typical 'requirement-iteration' case. From initial procurement to the final upgraded solution, we outline the entire process for industry reference. I. First Batch Procurement: Initial Trial and Limitations In early 2024, a municipal sanitation department (hereinafter referred to as 'the Unit') introduced sewage treatment vehicles for the first time, primarily to perform septic tank cleaning and sewage transportation in older urban residential communities. With a budget capped at approximately RMB 343,000 per unit, the Unit referenced publicly available tender information and selected a widely used Dongfeng Dorica chassis (wheelbase: 3308 mm) 4-cubic-meter vacuum suction truck. This model is equipped with a National VI emission-compliant engine, with chassis announcement number CLW5070GSSD6. The superstructure features a standard vacuum tank, vacuum pump, and a basic filtration system. Three units were procured initially at a unit price of around RMB 100,000 (in line with local procurement practices), mainly for routine sewage suction and transport. However, after six months of operation, the Unit reported several significant shortcomings: • Limited Treatment Capability: The vehicle only performs suction operations and lacks preliminary solid-liquid separation or purification functions, resulting in strong odors and high risks of leakage during transportation. • Operational Inefficiency: With a tank capacity of only 3–4 cubic meters, multiple round trips are required for large-volume sewage pits (e.g., septic tanks in older residential areas), leading to increased fuel consumption and time costs. • Emission Compliance Pressure: Stricter local regulations on vehicle sealing performance for sewage transport have rendered the original basic sealing system non-compliant with annual inspection standards. The Unit realized that conventional vacuum suction trucks alone could no longer meet increasingly stringent environmental protection and efficiency requirements—and thus needed an intelligent, integrated sewage treatment vehicle solution. II. Identifying Shortcomings and Upgrading Requirements: Transitioning from Suction to Treatment In early 2025, the Unit launched its second procurement initiative, shifting core requirements from 'suction-only' to 'treatment + transportation'. Key enhancement requirements included: • Solid-Liquid Separation Functionality: Equipped with either a screw-extrusion or centrifugal dewatering device to separate and compress solid waste (e.g., fecal sludge, debris) from sewage, significantly reducing transport volume. • Integrated Operation: Full-process capability covering suction, treatment, separation, and discharge—with treated effluent meeting municipal pipeline discharge standards or suitable for landscape irrigation. • Chassis Upgrade: Continued use of the National VI Dongfeng 3308 mm wheelbase chassis to ensure compatibility with the local maintenance network (Dongfeng chassis offers nationwide warranty coverage), while requiring customized superstructure design. • Cost Control: Budget maintained at approximately RMB 286,000–343,000 per unit (per public tender references), emphasizing cost-effectiveness and low long-term maintenance expenses. After comprehensive evaluation, the Unit found Chengli Special Purpose