1. Background and Importance of River Dredging

River dredging is an essential component of water environment management and is widely applied in urban river rehabilitation, flood control, black-odour water remediation, and landscape water system maintenance.

With long-term operation, sediments gradually accumulate on the riverbed, which may reduce flood discharge capacity and negatively affect aquatic ecosystems and surrounding environments.

Therefore, well-organised dredging operations combined with appropriate sludge treatment methods are critical to ensuring effective river restoration and smooth project implementation.

2. Basic Characteristics of Dredged Sludge

Sludge generated during river dredging differs significantly from conventional wastewater treatment plant sludge and typically exhibits the following characteristics:

- High moisture content

Dredging is often performed using hydraulic or wet methods, resulting in sludge with high water content and good fluidity.

- Complex composition and poor uniformity

 The sludge may contain organic sediments, fine sand, humus, and other impurities, with properties varying by river section and dredging depth.

- Project-based and concentrated treatment requirements

River dredging is usually carried out as a project-based operation, placing higher demands on sludge volume reduction and transportation efficiency.

These characteristics highlight the importance of effective dewatering during subsequent treatment stages.

3. Role of Sludge Dewatering in River Dredging Projects

In river dredging projects, sludge dewatering is not merely a standalone process but a key intermediate step connecting dredging operations with final transportation and disposal. Its main functions include:

- Reducing moisture content and transport volume

Dewatering significantly decreases sludge volume, helping reduce transportation and disposal costs.

- Improving sludge handling properties

Dewatered sludge is easier to stack, transport, and further treat.

- Optimising site management

Reduced leakage and overflow from liquid sludge help control secondary pollution risks on-site.

The stable performance of the dewatering stage directly affects overall project efficiency and construction progress.

4. Application Considerations of Belt Filter Presses in River Dredging

Considering the high moisture content and concentrated processing requirements of dredged sludge, belt filter presses are often adopted as one of the applicable dewatering options in river dredging projects. Their application is mainly based on the following principles:

- A process combining gravity drainage and mechanical pressing

The combination of gravity zones and pressure zones enables the gradual release of free water from sludge.

- Continuous operation suitable for large-volume treatment

Well suited to continuous sludge discharge during dredging operations.

- Relatively simple structure for on-site operation and maintenance

Offering flexibility for temporary or semi-permanent dredging project setups.

In practice, equipment selection should always be evaluated comprehensively based on sludge properties, treatment capacity, and site conditions.

5. Engineering Value of Proper Dewatering System Configuration

Through the proper configuration of dewatering equipment and auxiliary systems, river dredging projects can achieve several practical benefits:

- Improved sludge volume reduction and reduced downstream transportation burden

- Enhanced site cleanliness and operational control

- Greater flexibility for subsequent disposal or reuse options

This is why sludge dewatering has become an increasingly important component of modern river remediation projects.

River dredging plays a vital role in water environment restoration, while also placing higher technical demands on sludge treatment processes. As a key stage in dredging projects, well-designed and reliably operated dewatering systems help improve overall efficiency and project quality.

In practical applications, final technical solutions should always be developed by professional teams based on specific project conditions.