نوع مقاله : مقاله پژوهشی
نویسندگان
1
Department of Water Science Engineering, Ahv.C., Islamic Azad University, Ahvaz, Iran.
2
Khuzestan Water and Power Organization, Ahvaz, Khuzestan, Iran
3
Department of Water Science Engineering, Ahv.C., Islamic Azad University, Ahvaz, Iran
10.22034/nawee.2026.584356.1225
چکیده
Objective: Treatment of highly turbid surface water remains challenging in low-cost decentralized systems. This study aims to evaluate the hydraulic performance of a novel integrated pre-sedimentation and multilayer horizontal roughing filtration system and to develop dimensionless design relationships for improved process optimization and scale-up.
Methods: A laboratory-scale physical model was constructed in a hydraulic flume at the Khuzestan Water and Power Authority, Iran. The system combined a 1 m stilling basin with a three-layer roughing filter (20 mm, 10 mm, and 2 mm media). Experiments were conducted under three filter lengths (260, 350, and 450 cm), three filtration velocities (0.20, 0.60, and 1.00 m h⁻¹), three operation times (10, 20, and 30 min), and three influent turbidity ranges (1500–2500 NTU), resulting in 81 experimental runs. Turbidity removal efficiency was used as the performance criterion, and input predictability was assessed using the Gamma Test.
Results: Filter length was identified as the dominant parameter, improving removal efficiency by approximately 9–10% when increased from 260 to 450 cm. Maximum efficiencies exceeded 94% at 0.20 m h⁻¹ and 450 cm length. Filtration velocity had a secondary negative effect (4–5% reduction across the tested range), while influent turbidity and operating time showed limited influence. The Gamma Test confirmed strong deterministic structure in the full-input configuration (Gamma = 0.0462; V-ratio = 0.1848).
Conclusions: The findings demonstrate that, within the tested range, increasing the effective length of the multilayer horizontal roughing filter improved turbidity removal performance and enhanced the overall efficiency of the combined pre-sedimentation–filtration system. These results indicate that filter length is an important design parameter for treating highly turbid surface waters in resource-limited regions. However, the present study should be interpreted as an experimental performance assessment of selected configurations rather than a formal geometric optimization, and determination of the absolute optimal design would require further investigation over a wider range of configurations together with techno-economic evaluation.
کلیدواژهها
