Removal of pesticides from water by NF and RO membranes — A review

The frequent detection of pesticides in water sources is of great concern to the public, to authorities and all those involved in potable water production, wastewater treatment and reuse, due to potentially adverse health effects associated with these compounds, even at very small concentrations. In view of problems inherent in conventional processes, for removing various pesticides and the multitude of other synthetic micropollutants, significant research efforts have been invested for developing effective potable water treatment methods based on membranes. The growing interest in such processes is justified on account of the high and stable water quality they can achieve, although their cost effectiveness needs improvement. Therefore, influenced also by social and legislative pressure for more stringent potable water quality regulations, membrane processes such as nanofiltration (NF) and low-pressure reverse osmosis (LPRO) are under development for broad applicability. The scope of this paper is to review our current understanding, gained from laboratory research, pilot and industrial-scale activity, regarding pesticides removal by membrane processes. A rather thorough discussion of pesticides rejection by membranes is provided, highlighting the prevailing mechanisms and main factors involved. Finally, an outline is provided of outstanding issues, both at the scientific and technological level, which require further investigation.