关键词:

ZnAlLa类水滑石, 污泥脱水液, 磷酸根, 吸附

Abstract:

A series of ZnAlLa layered double hydroxides (LDHs) were synthesized by the coprecipitation method，and their structure and phosphate adsorption capacities were studied.The results showed that the layered structure was maintained when a proper amount of La was added as a trivalent cation into ZnAl LDHs.At the Zn∶Al∶La molar ratio of 2.00∶0.90∶0.10，the phosphate adsorption by the obtained ZnAlLa LDHs in 24 h was 35.15 mg P·g^-1，which was 41.9% higher than that by the La-free LDHs.After calcination at 300℃，the ZnAlLa LDHs were transformed to metastable mixed metal oxides with a higher specific surface area.The phosphate adsorption by the calcined LDHs was 1.48-fold higher when compared with that by the raw material.The phosphate adsorption by the ZnAlLa showed a high stability against pH variation and competing ions in the solution.The adsorption kinetics followed a pseudo-second-order model and the isotherms were of the Langmuir type.

Key words:

ZnAlLa类水滑石, 污泥脱水液, 磷酸根, 吸附