Engineered Photocatalytic Material Membrane Assemblies for Removing Nitrate from Water

LiNbO 3, as a nonlinear optical material (NLO), can remove nitrate from water via photocatalytic denitrification (PCDN), which has received increasing attention in the field of water treatment. In this work, efficient denitrification of water was achieved by coating a poly(ether sulfone) (PES) support membrane with a hydrothermally synthesized LiNbO 3 powder. The photocatalytic membrane could achieve a water flux of 237 ± 12 L m –2 h –1 per bar with a LiNbO 3 and polyethylenimine assembly. In addition, the photocatalytic membrane possess inherent and unique advantages over common ultrafiltration membranes, such as separation performance and antifouling properties. In addition, the LiNbO 3 has been successfully applied to the membrane materials, endowing the membrane with high photocatalytic activity. The photocatalytic denitrification experiments on the membranes indicated that the low concentration of nitrate(10 mg L –1 ) can be reduced to N 2 via CO 2 •– radicals under conditions of a 365 nm UV light source, with 81.82% nitrate removal and 98.29% photocatalytic selectivity toward nitrogen. The above results imply that the prepared photocatalytic membranes have the potential to be used in future separation technologies and for water treatment procedures to remove nitrate.