Self-cleaning biomimetic superhydrophobic PVC plates for fouling mitigation in lamella settlers

Lamellar sedimentation is widely used in water treatment, but particle accumulation on inclined plates can obstruct channels and impair hydraulic performance. This laboratory-scale proof-of-concept evaluated the effect of surface wettability on sedimentation and residual fouling by comparing smooth PVC and biomimetic superhydrophobic (Sh) plates in a batch lamella settler. Quartz suspensions were tested at plate inclinations of 20°, 40°, and 60°. Superhydrophobic plates reduced residual sediment deposition by up to 99% relative to conventional PVC while maintaining statistically comparable settling performance. Gravimetric and image-based analyses confirmed fouling suppression. During tank drainage, deposited quartz was progressively removed from Sh plates as the water-air interface receded. All Sh plates retained static water contact angles above 150° after three cumulative batch-exposure stages. These results demonstrate that surface engineering can mitigate residual fouling without measurably compromising batch settling performance. Further investigation under continuous-flow conditions is required to assess these effects under operational hydrodynamic conditions. • Superhydrophobic plates reduce sediment deposition by up to 99% via self-cleaning • Self-cleaning enables operation at lower inclination angles • Surface material selection reduces the settling-fouling trade-off • Material-dependent effects on self-cleaning are most pronounced at low angles • Superhydrophobic surfaces retain functionality after repeated abrasive cycles