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Municipal pipe dredging, river dredging and underground construction generate large volumes of slurry that is difficult to transport and expensive to dispose of. A modular slurry treatment system s

Municipal pipe dredging, river dredging and underground construction generate large volumes of slurry that is difficult to transport and expensive to dispose of. A modular slurry treatment system solves this problem by washing, classifying and dewatering the sludge on site, recovering clean aggregates and recycling process water. This article explains how a slurry treatment system works, which modules it contains, and how it reduces the cost of sludge disposal.

Why Slurry Needs On-Site Treatment

Untreated slurry typically contains more than 80 percent water, which makes haulage costly and increases the burden on landfill or treatment facilities. On-site treatment brings three immediate benefits:

• Volume reduction: solid content is separated and dewatered, so the amount of material leaving the site drops sharply.
• Resource recovery: sand and coarse aggregates are washed, classified and reused as construction materials.
• Water recycling: treated water is returned to the process, reducing fresh water consumption.

Core Modules of a Slurry Treatment System

The DS-STS series slurry treatment system from Desen Environmental is built from independent modules that can be arranged according to the site conditions. A typical configuration includes the following units:

• Scrubbing module with a drum scrubber that separates clay lumps from sand and stone.
• Primary screening module for removing oversized particles.
• Soaking and classifying module where chemicals react with the slurry and fine sand is recovered.
• Secondary concentrating module using a deep cone thickener.
• Solid-liquid separation module with a plate and frame filter press.
• Water treatment module that cleans the filtrate for reuse.
• Electrical control module with DCS and 5G cloud monitoring.

Typical Process Flow

Slurry with a maximum particle size of 150 mm is fed into the drum scrubber together with water at a ratio of about five to one. Inside the scrubber, the material is lifted, rubbed and dropped repeatedly, so clay lumps are broken down and the sand is washed clean. Material larger than 20 mm is removed by a screen at the discharge end. The remaining slurry then passes through a primary sieve where particles larger than 2 mm are separated. The fine fraction enters the soaking and classifying module, where reagents are added and light floating debris is removed by scrapers. A multi-stage screw classifier recovers sand in the 0.075 to 2 mm range. The remaining slurry is flocculated in a deep cone thickener and finally dewatered by a plate and frame filter press. The filtrate goes to the water treatment module and is recycled into the process.

Key Performance Indicators

• Processing capacity: 5 to 100 tonnes per hour for modular systems, up to 15 tonnes per hour for truck-mounted units.
• Aggregate recovery rate: over 95 percent.
• Filter cake moisture content: no more than 40 percent.
• Installation period: roughly 10 days on site, with no concrete foundation required.
• Footprint: about 600 square metres for a 15 t/h line.
• Operating crew: two to three people per shift.

Project Experience

Desen has delivered slurry treatment systems for municipal and construction applications in China. In Jiangxi province, a modular system processes ditch and dredged sludge at 15 tonnes per hour with a total installed power of 224.85 kW and a crew of two per shift. In Nansha, Guangzhou, an 8 t/h system handles urban pipeline sludge with PLC-based controls.

Conclusion

A modular slurry treatment system turns difficult sludge into reusable sand, dewatered cake and clean water. For projects dealing with dredged sludge, tunnel slurry or pipeline sediment, on-site treatment reduces transport cost, shortens the disposal cycle and improves the overall economics of the worksite. Contact Desen Environmental to discuss a system sized for your project.