秸秆基Li/Al层状双金属氢氧化物纳米复合吸附剂的制备及其除磷性能研究

将纳米Li/Al层状双金属氢氧化物(LDH)负载到改性小麦秸秆上制得秸秆基Li/Al LDH纳米复合吸附剂(简称复合吸附剂),并通过一系列单因素吸附试验对其除磷性能进行评价。结果表明:升高温度有利于该吸附剂的吸附;最佳吸附pH约为4;动力学实验表明,100min时吸附过程即可达到平衡;以NO_3^-、Cl-、SO_4^2-作为共存离子,3者对于复合吸附剂除磷的影响程度为SO_4^2->Cl->NO_3^-,且共存离子浓度较高时复合吸附剂对磷仍有较好的吸附选择性;脱附再生实验表明,使用5mol/L NaOH和0.01mol/L NaCl的混合溶液可达到较好的脱附效果。

Development of Li/Al LDH-loaded nanocomposite for removal of phosphorus from water

The nanosized Li/Al layered double hydroxide(LDH)particles were loaded onto the modification wheat straw to prepare a straw based Li/Al composite adsorbent,and the adsorption performance of the nanocomposite was evaluated through a series of single factor adsorption experiments.The results showed that high temperature was beneficial to adsorption of the adsorbent.The optimal adsorption pH for phosphorus removal was about 4.Kinetic experiments showed that the adsorption process could reach equilibrium within 100 min.NO3^-,Cl^-and SO4^2-were used as competitive ions,and their effects on phosphorus removal by nanocomposite were as follows:SO4^2- >Cl^- >NO3^-.The straw-based Li/Al composite exhibited high preference toward phosphorus when competing anions coexisted at relatively high levels.Desorption regeneration experiments showed that the exhausted adsorbent could be effectively regenerated by a mixture of 5 mol/L NaOH and 0.01 mol/L NaCl.