Performance of river sediments after flocculation-pressure filter membrane-vacuum preloading.

Area of Science:

• Environmental Engineering
• Water Treatment Technologies
• Sediment Management

Background:

• River bottom sediment dewatering presents significant challenges, with traditional methods being time-consuming and costly.
• Efficient sludge dewatering is crucial for sediment reduction and environmental remediation projects.

Purpose of the Study:

• To investigate and compare the effectiveness of various flocculant treatments for river sediment dewatering.
• To analyze the impact of different treatments on sludge dewatering efficiency, water quality, and sediment properties.

Main Methods:

• Compounding multiple flocculants based on sludge characteristics.
• Conducting sedimentation and supernatant turbidity tests to determine optimal treatments.
• Performing flocculation-vacuum preloading dewatering tests.
• Analyzing dewatering performance, water quality, pore water pressure dissipation, and shear strength.

Main Results:

• Polysilicate aluminium ferric (PSAF) significantly enhanced dewatering efficiency, achieving a final dewatering amount of 310 g.
• PSAF demonstrated superior water purification compared to polyacrylamide (PAM) and polyaluminium chloride (PAC).
• PAM provided the best vane shear strength, while lime improved vacuum preloading and shear strength when combined with other flocculants.

Conclusions:

• Optimized flocculant combinations, particularly those involving PSAF and PAM, offer efficient solutions for river sediment dewatering.
• The study highlights the potential of advanced treatment methods to overcome the limitations of natural air drying.
• The selection of flocculants should consider a balance of performance, cost, and specific treatment goals.