AWWA QTC98377

This paper assesses performances of activated carbon cloths (ACC) in water treatment. Two different approaches are described. First, a batch reactor monitors and generates data for organics present in the water. The possibilities of ACC utilization are then studied in dynamic systems. The head loss and the adsorption capacities are determined as a function of operating conditions. The main characteristics of ACC are determined: BET surface area; pore volume distribution; and, surface functional groups and elementar analysis. This material is also shown by scanning electronic or atomic force microscopy. Adsorption of natural organics (humic substances) and micropollutants (aromatics, pesticides, solvents) is carried out in batch reactors. Results show that the performances of ACC are significant in terms of adsorption velocity, and that selectivity could be an interesting property of this kind of adsorbent. The second approach uses a dynamic reactor, which determines head loss by using a pilot plant unit. From experimental data a model is proposed to describe and calculate the evolution of the pressure drop as a function of fluid velocity. The breakthrough curves obtained with ACC system suggest a smaller mass transfer zone than with granular activated carbon, about 3.5 mm. The adsorption capacities corresponding to micropollutants removal are determined.



Keywords: Adsorption; Performance; Reactors; Organics; Head Loss; Microscopy ; Humic Substances; Modeling; Kinetics; Equilibrium; Velocity; Mass Transfer