Abstract：Three kinds of commonly vertical flow constructed wetlands substrates, such as biological ceramsite, anthracite and zeolite, were selected. After the MgCl2 and FeCl3with the metal molar ratio (M2+: M3+) of 2:1were co-precipitated in alkaline conditions to synthesize MgFe-LDHs, the synthesized MgFe-LDHs were in-situ coated on the surface of three kinds of substrates. The simulated substrates test columns were constructed to treat the contaminated lake water using formerly substrates before and after modification. The method of synthesized LDHs being in-situ coated on substrates of vertical flow constructed wetland was feasible. After the modification, the purification effects of CODCr, ammonia nitrogen and total phosphorus were improved by various degrees. Among them, the modified anthracite had optimal performance with average removal efficiencies of CODCr, ammonia nitrogen and total phosphorus more than 80%, 60% and 90%, respectively.
