Government Procurement Case and Bid-winning Solution Interpretation for Dongfeng Wing-Opening Wastewater Treatment Vehicle in Wuxi. In early 2025, a municipal sanitation department in a district of Wuxi planned to procure a batch of wastewater treatment vehicles for daily operations including river and ditch cleaning, as well as emergency sewage discharge. Following multiple rounds of public tendering and solution evaluation, the department ultimately selected several models featuring Dongfeng wing-opening chassis paired with Chengli superstructures. Based on authentic tender information from this case (referencing publicly available tender documents), this article provides a comprehensive reference for similar procurement needs — covering volume selection, daily workload matching, and the final bid-winning solution. I. Procurement Background and Requirement Analysis The municipal sanitation department oversees urban main roads, old residential communities, and some industrial parks, facing diverse daily wastewater treatment scenarios. Preliminary research indicated a daily wastewater treatment requirement of approximately 300–500 cubic meters, with an emergency response time requirement of within 30 minutes. After expert review, it was decided to procure multiple wastewater treatment vehicles of varying capacities to balance operational efficiency and flexibility. During model selection, three key criteria were prioritized: tank capacity (determining single-operation volume), chassis maneuverability (to navigate narrow alleys and complex road conditions), and emission standards (all models comply with China VI regulations to meet environmental requirements). The final solution selected the Dongfeng wing-opening chassis — recognized for its high frame load-bearing capacity and wing-opening body design that facilitates equipment maintenance, offering outstanding cost-effectiveness among comparable products. II. Tank Capacity Selection: How to Choose Among 3 m³ / 5 m³ / 8 m³ / 12 m³ Models? According to Chengli Special Purpose Vehicle’s product database and the tender documents for this case (referencing publicly available tender information), selection of wastewater treatment vehicle capacity must consider daily workload, transport distance, and operation frequency. Below is the logic applied in this case: 3 m³ Model: Suitable for narrow areas such as old residential communities and backstreets; handles ~3 tons of wastewater per operation. Two units were procured for routine inspection and small-scale emergency response. 5 m³ Model: The primary workhorse model, balancing maneuverability and efficiency; handles 5 tons per operation. Four units were procured, covering 80% of routine operations. 8 m³ Model: Designed for high-flow operations in industrial parks or major/secondary arterial roads; handles 8 tons per operation. Two units were procured for priority zones. 12 m³ Model: Intended for large-scale engineering projects or emergency rescue; handles 12 tons per operation. One unit was procured as a mobile reserve. Selection was primarily guided by the following formula: Daily Workload (m³/day) = Single-Operation Volume (m³) × Daily Operation Frequency × Number of Simultaneously Operating Vehicles For example, using the 5 m³ model operating four times daily (every two hours) with four vehicles working concurrently yields a daily processing capacity of: 5 × 4 × 4 = 80 m³. Combined with the 8 m³ and 12 m³ models, the total capacity meets the required 300–500 m³/day range. III. Daily Workload Calculation Formula and Workload Matching Table To assist procurement entities in precise capacity matching, this case provides the following calculation formula and matching table (data derived from official parameters of Chengli models such as CLW5070GSSD6, referencing publicly available tender information): Vehicle Model Capacity | Single-Operation Volume (tons) | Recommended Operation Frequency (times/day)