Fluidisation characteristics of granular activated carbon in drinking water treatment applications

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...

Accurate voidage prediction in fluidisation systems for full-scale drinking water pellet softening reactors using data driven models

In full-scale drinking water production plants in the Netherlands, central softening is widely used for reasons related to public health, client comfort, and economic and environmental benefits. Almost 500 million cubic meters of water is softened annually through seeded crystallisation in fluidised bed reactors. The societal call for a circular...

Improvement of voidage prediction in liquid-solid fluidized beds by inclusion of the Froude number in effective drag relations

A novel effective drag relation for liquid-solid fluidisation is proposed, suitable for application in full-scale installations. This is achieved by presenting new insights related to the influence of the temporal-spatial heterogeneity on the effective hydrodynamic drag for large fluidised systems. While heterogeneous flow behaviour can be...

Improvement of the Richardson-Zaki liquid-solid fluidisation model on the basis of hydraulics

One of the most popular and frequently used models for describing homogeneous liquid-solid fluidised suspensions is the model developed by Richardson & Zaki in 1954. The superficial fluid velocity and terminal settling velocity together with an index makes it possible to determine the fluid porosity in a straightforward way. The reference...

Drinking water pellet softening: prediction the terminal settling velocity of natural particles

Natural particles are frequently applied in drinking water treatment in up-flow fluidisation processes. Additionally, sedimentation processes are applied to clarify water and to concentrate solids. To estimate the terminal settling velocity of single solid particles in a liquid system, a comprehensive collection of equations is available. For...

Prediction of the terminal settling velocity of drinking water pellet softening particles

The literature provides a comprehensive collection of equations to estimate the<br/>terminal settling velocity of single solid particles in a liquid system. The settling velocity for perfectly round spheres can accurately be calculated. In the contrary for natural imperfect particles the experimentally measured settling velocity deviates...

Model-based prediction of fluid bed state in full-scale drinking water pellet softening reactors

Softening at drinking water treatment plants is often realised by fluidised bed pellet reactors. Generally, sand is used as seeding material and pellets are produced as a by-product. To improve to sustainability, research has been carried out to replace the seeding material by re-using grained and sieved calcite pellets as seeding material. An...