Granular and Dissolved Polyacrylamide Effects on Erosion and Runoff under Simulated Rainfall

Area of Science:

• Soil Science
• Environmental Engineering
• Water Resource Management

Background:

• Polyacrylamide (PAM) is known to mitigate soil erosion.
• Limited data exists on how PAM application methods affect erosion control and runoff concentrations.

Purpose of the Study:

• To evaluate the effectiveness of an excelsior erosion control blanket combined with two PAM application methods (granular and dissolved) on soil erosion.
• To compare the impact of granular PAM (GPAM) and dissolved PAM (DPAM) on runoff turbidity, total suspended solids (TSS), sediment particle size, and PAM loss.

Main Methods:

• A rainfall simulation study using soil-packed runoff boxes.
• Treatments included: control, cover only, cover + GPAM, and cover + DPAM.
• Runoff analysis for turbidity, TSS, sediment particle size, and PAM concentration.

Main Results:

• The erosion control blanket alone reduced turbidity and TSS by over 60%.
• PAM application further decreased turbidity and TSS by over 30%.
• PAM treatments increased the median particle diameter of eroded sediment seven to ninefold.
• Dissolved PAM (DPAM) showed significantly lower PAM loss in runoff (2%) compared to granular PAM (GPAM) (19%).

Conclusions:

• Both GPAM and DPAM enhance the performance of erosion control blankets.
• DPAM is a more efficient application method due to substantially lower PAM loss in runoff water.