Continuous flow hydrodechlorination for micropollutants removal using an innovative Pd-based Catalytic Membrane Reactor

The aim of this work is to develop a Pd-based Catalytic Membrane Reactor (Pd/CMR) for its application in organochlorinated micropollutants removal by hydrodechlorination (HDC). The external surface of a Al2O3 membrane was homogeneously decorated by Pd nanoparticles (0.2% wt.). The Pd/CMR developed system allowed the treatment of a continuous water flow by HDC and offered significant advantages in terms of cost, design and manufacture. In this work, the Pd/CMR system was employed for the HDC of the anti-inflammatory drug diclofenac (DCF) under ambient conditions. The Pd/CMR system showed a remarkable stability upon long-term reaction and 64% of DCF conversion. The initial DCF concentration did not modify the final conversion achieved, so the reaction can be accurately described by a pseudo-first order kinetic model. Furthermore, the versatility of the system was demonstrated in a real aqueous matrix (tap water). Finally, it was evidenced the notable feasibility of the Pd/CMR system for scaling-up the HDC process since the catalytic membrane reactor worked satisfactorily for up to 200 h.