Process combination of nanofiltration and adsorption: optimisation of an air and back flushing procedure

A new process combination integrating adsorption on powdered adsorbent into a nanofiltration process is applied to landfill leachate treatment on a pilot scale. Lab scale experiments have shown that the permeate flux is significantly increased by the application of a flushing procedure combining permeate back flushing and feed and air cross flow flushing. In this paper an optimisation strategy for the flushing procedure is described and first experimental results are presented. These results indicate that the cross flow flushing velocity and the number of permeate side pressure pulses are the major factors of the flushing procedure.