ABSTRACT
Zn-Layered double hydroxides (LDHs) were selected to carry out the experiment in present work based on the previous research results. According to the co-precipitation method, three kinds of different Zn-LDHs (FeZn-LDHs, CoZn-LDHs and AlZn-LDHs) were synthesized by ZnCl2, FeCl3, AlCl3, and CoCl3 solution in alkaline conditions and Zn-LDHs were in-situ coated on the surface of natural zeolites. With the filling of the natural and three kinds of Zn-LDHs modified zeolites in the columns, test experiments were conducted to study the removal performance of phosphorus in vertical-flow constructed wetlands. The results showed that: compared with the natural zeolites, the removal rates of phosphorus by the three kinds of Zn-modified zeolites were greatly improved, especially for FeZn-LDHs. Moreover, the maximum adsorption capacity and the desorbed performance of phosphate were enhanced by the Zn-LDHs coated modification. The adsorption type of phosphate was converted from physical adsorption to chemical adsorption. Through reasonable selection of the type of zeolite and the method of modification, Zn-LDHs modified zeolites could be used to enhance the removal of nitrogen and phosphorus for the eutrophic water.