Design parameters for implementing inclined plate settlers in sedimentation tanks

Abstract

This study evaluates the hydraulic and operational performance of inclined plate settlers (IPS) as an enhancement to conventional sedimentation tanks in wastewater treatment. IPS, also known as lamella clarifiers, increase effective settling surface area within a compact footprint, addressing the space and retention-time limitations of traditional tanks. A laboratory-scale pilot was constructed to investigate the effects of plate inclination, spacing, vertical height, and surface texture on the removal of total suspended solids (TSS). Synthetic wastewater (200–250 mg/L clay suspension) was tested through five configurations of flat and corrugated PVC plates under varying geometries, with hourly sampling over six-hour runs. Results showed that plate inclination was the most influential factor, with efficiencies improving from 45° to 65°; narrower spacing (2.5 cm) outperformed wider spacing (5cm); taller plates (15cm) improved capture of slower-settling particles; and corrugated surfaces enhanced removal by increasing surface area. The optimized configuration (15cm corrugated plates, 2.5 cm spacing, 65° inclination) achieved up to 99% TSS removal. Comparative analysis with global case studies confirmed the scalability and practicality of IPS for compact, cost-effective retrofitting. Overall, IPS are validated as a robust technology bridging theory and application, offering significant improvements in sedimentation efficiency for modern wastewater treatment.