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Solidification effect of river bottom sediments after flocculation via different composite flocculants
Linzhu Sun1, Yunyun Zheng1, Xiaoniu Yu2,3
1College of Civil Engineering and Architecture, Wenzhou University, Wenzhou, 325035, China.
Environmental Science and Pollution Research International
|October 21, 2020
Summary
Dewatering river sediments is challenging. This study optimized composite flocculants, like polyacrylamide (PAM) and polysilicate aluminum ferric (PSAF), improving sediment dewatering efficiency and compressive strength.
Area of Science:
- Environmental Engineering
- Geotechnical Engineering
- Materials Science
Background:
- River bottom sediment dewatering is critical for environmental remediation and infrastructure projects.
- Traditional methods like natural air drying are time-consuming and costly.
- Developing effective composite flocculants is essential for efficient sediment treatment.
Purpose of the Study:
- To evaluate the efficacy of composite flocculants for dewatering river sediments.
- To determine optimal ratios of anionic polyacrylamide (PAM), polyaluminum chloride (PAC), polysilicate aluminum ferric (PSAF), and iron perchloride (IC).
- To assess the impact of flocculation and curing agents on sediment properties.
Main Methods:
- Sedimentation column tests were performed to analyze sedimentation rates.
- Turbidity and pH of supernatant were measured to evaluate flocculation effectiveness.
- Compressive strength was tested at varying curing agent dosages and times.
Main Results:
- An optimal ratio of 3:7 was found for two types of polyacrylamide (PAM).
- Polysilicate aluminum ferric (PSAF) effectively reduced supernatant turbidity.
- Composite flocculants achieved a relative water content of approximately 60% and improved compressive strength with increased curing agent.
Conclusions:
- Composite flocculants, particularly combinations involving PAM and PSA F, offer an efficient solution for river sediment dewatering.
- The study identified effective flocculant combinations and curing strategies for sediment management.
- Optimized dewatering and solidification enhance the potential for sediment reuse and disposal.
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