Some of the anaerobic bacterium fermented bio-methane can adsorb heavy metals
such as Pb2+
which are enriched in biogas slurry and residue. For this reason
the detection and removal of heavy metal ions
such as Pb2+ ion in biogas slurry and residue is one of the key problems in the study of bio-methane systems. 18-crown-6 has remarkable recognition ability towards Pb2+ ion. The Pb2+ ion-recognition-responsive smart materials composed of 18-crown-6 and poly(N-isopropylacrylamide) (PNIPAM) have been developed. In this paper
the progress of investigation on Pb2+ ion-recognition-responsive smart polymeric materials based on 18-crown-6 and poly(N-isopropylacrylamide) for detection and removal of Pb2+ is reviewed.