Fluidisation characteristics of granular activated carbon in drinking water treatment applications

Journal article (2021)

Authors

O.J.I. Kramer Waternet, Hogeschool Utrecht, Complex Fluid Processing - Mechanical, Maritime and Materials Engineering , Queen Mary University of London
C. van Schaik Hogeschool Utrecht, Waternet
P.J. de Moel Sanitary Engineering - CEG
E.S. Boek Queen Mary University of London
E.T. Baars Waternet
J.T. Padding Complex Fluid Processing - Mechanical, Maritime and Materials Engineering
J.P. van der Hoek Waternet, Sanitary Engineering - CEG
Research Group
Complex Fluid Processing (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2021 O.J.I. Kramer, C. van Schaik, P.D.R. Dacomba Torres, P.J. de Moel, E.S. Boek, E.T. Baars, J.T. Padding, J.P. van der Hoek
DOI: https://doi.org/10.1016/j.apt.2021.06.017
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Published Date

2021

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Process and Energy

Research Group

Complex Fluid Processing

Abstract

Granular activated carbon (GAC) filtration is an important unit operation in drinking water treatment. GAC filtration is widely used for its filtration and adsorption capabilities as a barrier for undesired organic macro- and micro-pollutants. GAC filtration consists of two successive phases: adsorption and filtration, capturing the impurities from the water in conjunction with a backwash procedure in which the suspended particles are flushed out of the system. Available literature predominantly focusses on adsorption. A less frequently discussed but nevertheless equally crucial aspect of this operation is the backwash procedure of GAC beds. To prevent accumulation of suspended particles and to avoid additional operation costs, optimal backwashing is required. Another factor is sustainability: water utilities are showing increasing interest in exploring new sustainable GAC media. As these have different bed expansion tendencies due to different GAC characteristics with varying geometries, operational developments are needed for prediction models to estimate the expansion degree during backwashing. The prediction of the bed expansion of GAC is complex as the particles are non-spherical, porous and polydisperse. Through a combination of advanced particle laboratory and fluidisation experiments, we demonstrate a new approach which leads to an improved expansion prediction model for the backwashing of GAC filters.