Effects of Cd2+ and Pb2+ on the substrate biofilms in the integrated vertical-flow constructed wetland

The effects of single Cd~(2 )and Pb~(2 ),and combined Cd~(2 )and Pb~(2 )on dehydrogenase activity and polysaccharide content of the substrate biofilms in the integrated vertical-flow constructed wetland(IVCW)were studied.Dehydrogenase activities decreased linearly with the increasing concentrations of Cd~(2 )and Pb~(2 )at different times(6,24,72,and 120 h).The activities at both 6 and 24 h were significantly higher than that at 72 and 120 h in the case of single and combined treatments.The single Cd~(2 )...