I. Project Background: Sewage Treatment Requirements of a Municipal Sanitation Department in Lanzhou — In 2026, a municipal sanitation department in Lanzhou plans to upgrade a batch of environmental operation vehicles, focusing on resolving sewage treatment challenges in urban areas and surrounding industrial parks. Located in Northwest China, Lanzhou is a typical desertification region characterized by heavy sandstorms and arid climate. Conventional sewage treatment equipment often suffers from poor sealing, frequent clogging of filtration systems, and high maintenance costs. After multiple rounds of research and tendering, Chengli Special Purpose Vehicle Co., Ltd. was selected to supply China VI-compliant Dongfeng 3308 mm wheelbase sewage treatment vehicles, with a total delivery of 5 units for daily sewage collection, transportation, and emergency response. II. Vehicle Selection Analysis: How to Choose Among 3 m³ / 5 m³ / 8 m³ Models? — Prior to this procurement, the customer compared multiple tank-volume models, with key considerations including: operational scenarios (urban pipeline sewage, temporary industrial park sewage ponds), single-trip operating radius (≤15 km), and adaptability to desertification conditions. Tank Volume | Applicable Scenarios | Estimated Daily Throughput | Adaptability to Desertification Conditions | Reference On-Road Price (Tax-Inclusive) ---|---|---|---|--- 3 m³ Sewage Treatment Vehicle | Residential septic tanks, small sewage wells | ~60–80 tons/day (based on 8 round trips) | Good sealing performance; however, filtration system requires cleaning every two weeks | ~¥95,000–¥120,000 (per publicly available tender data) 5 m³ Sewage Treatment Vehicle | Urban trunk road sewage collection, industrial parks | ~100–130 tons/day (based on 6 round trips) | Standard dust-proof sealing strips; filtration system recommended for inspection weekly | ~¥145,000–¥178,000 (per local procurement practice) 8 m³ Sewage Treatment Vehicle | Large-scale sewage ponds, emergency response | ~150–200 tons/day (based on 5 round trips) | Heavy-duty chassis, high dust-protection rating; filtration system cleaning interval extendable to three weeks | ~¥198,000–¥245,000 (per publicly available tender data) Note: Daily throughput estimates assume a one-way transport distance of 10 km and an average operation time of ~1 hour per trip (including suction/discharge and cleaning). Actual efficiency may vary depending on road conditions, sewage viscosity, etc. After comprehensive evaluation, the municipal department ultimately selected the 5 m³ model as the primary unit (3 units), supplemented by 2 units of the 3 m³ model for operations in narrow streets. The 5 m³ model utilizes the Dongfeng 3308 mm wheelbase chassis (reference model series: CLW5070GSSD6), compliant with China VI emission standards and meeting Lanzhou’s environmental requirements. Chengli Special Purpose Vehicle provided a detailed configuration list during bidding, including: tank body material — Q235 carbon steel, thickness 4 mm; dust-proof sealing strips (customized for desertification environments); and a reinforced air filter, with recommended maintenance intervals of cleaning every 10 days or every 200 operating hours. III. Daily Throughput Calculation Formula and Workload Matching Table — To assist users in more precise vehicle selection, Chengli’s technical team provides the following throughput calculation formula: Daily Throughput (tons/day) = Tank Capacity (tons) × Daily Round Trips × Loading Factor (typically 0.9) Wherein, daily round trips depend on one-way distance and operational efficiency (including suction/discharge time, cleaning, and waiting). General empirical values are: ~10–12 trips for ≤5 km one-way distance; ~6–8 trips for ≤10 km; ~