Depollution of waters contaminated by phenols and chlorophenols using catalytic hydrogenation

Abstract

A new process for the detoxification of phenol-containing waste waters based on catalytic hydrogenation suitable for a wide range of compounds is proposed. After an introduction pointing out the advantages of this approach, the principle of the multifunctional process is presented. Then two examples of application of this process for the treatment of polluted waste waters are reported; one containing chlorophenols and the other containing mixture of phenols of olive oil waste water. Using 4-chlorophenol as a model molecule of monoaromatic chlorophenols and tyrosol of phenols encountered in olive oil waste waters, the kinetics of catalytic hydrogenation was studied. In both cases, a scheme of the reaction was elucidated, different kinetics models were established and a dynamic simulation software was used for helping in their discrimination and for parameter estimation. In both cases, total conversion was achieved. The global rate of 4-chlorophenol conversion into cyclohexanol at 0.4 mpa and 353 K was 3.43 g h-1gcatalyst-1 while the rate of tyrosol conversion at 1 mpa and 353 K was 1.42 g h -1gcatalyst-1. © 2005 Springer-Verlag Berlin Heidelberg.