title: Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.
abstract: Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits.
authors.affiliation: Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Macul, Santiago, Chile.
authors.forename: F
authors.initials: F
authors.lastname: Tarud
authors.forename: M
authors.initials: M
authors.lastname: Aybar
authors.forename: G
authors.initials: G
authors.lastname: Pizarro
authors.forename: R
authors.initials: R
authors.lastname: Cienfuegos
authors.forename: P
authors.initials: P
authors.lastname: Pastén
mesh_terms: D004301:Doppler Effect; D005456:Fluorescent Dyes / Q000032:analysis*; D012212:Rheology; D013050:Spectrometry, Fluorescence; D018505:Waste Management / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes