Zhang Xiang-Ling, Chen Jun-Jie, Guo Lu, Chen Qiao-Zhen, Wang Xiao-Xiao
Huan Jing Ke Xue. 2014 Dec;35(12):4553-9.
Six kinds of metal compounds which were CaCl2 , ZnCl2, MgCl2, FeCl3, AlCl3, and CoCl3 were formed nine kinds of different combinations in the alkaline conditions to synthesized LDHs (Layered Double Hydroxides), which were in-situ coated on the surface of zeolites. With the filling of the original and nine kinds of modified zeolites in the columns to simulate a laboratory-scale vertical-flow constructed wetland system, the experiments of purified phosphorus were conducted. Combined removal efficiency with adsorption isotherm data of the ten kinds of zeolites, mechanism for strengthening the removal rates of the phosphorus by the modified zeolites was studied. The results showed that compared with the original zeolites, the removal rates of the phosphorus by nine kinds of modified zeolites were enhanced with various degrees. In the cases of Zn involved in the modified zeolites, the removal efficiencies of phosphorus reached a high quality. Especially, the ZnFe-LDHs had the average removal rates of the total phosphorus, the dissolved phosphorus and the phosphate were over 90%, and its maximum adsorption capacity of the phosphorus was three times higher than that of the original zeolites. Therefore, by means of increasing the adsorption capacity and improving the chemical adsorption ability of phosphorus, the modification to coated LDHs on the zeolites reached the aim of strengthening the purification of the phosphorus.
六种金属化合物，即氯化钙、氯化锌、氯化镁、氯化铁、氯化铝和氯化钴，在碱性条件下形成九种不同组合以合成层状双氢氧化物（LDHs），并将其原位包覆在沸石表面。通过在柱中填充原始沸石和九种改性沸石来模拟实验室规模的垂直流人工湿地系统，进行了磷净化实验。结合十种沸石的吸附等温线数据和去除效率，研究了改性沸石提高磷去除率的机制。结果表明，与原始沸石相比，九种改性沸石对磷的去除率均有不同程度的提高。在含有锌的改性沸石中，磷的去除效率达到了较高水平。特别是，锌铁层状双氢氧化物对总磷、溶解性磷和磷酸盐的平均去除率超过90%，其对磷的最大吸附容量比原始沸石高两倍。因此，通过提高吸附容量和改善对磷的化学吸附能力，在沸石上包覆层状双氢氧化物的改性达到了强化磷净化的目的。
