Abstract:
Heavy metals and organic pollutants are prevalent in water bodies, causing great damage to the environment and human beings. Hence, it is urgent to develop a kind of adsorbent with good performance. Anion interlacing layered double hydroxides (LDHs) are a promising adsorbent for the sustainable removal of heavy metal ions and dyes from wastewater. Using aluminum chloride, zinc chloride and ammonium pentaborate tetrahydrate (NH4B5O8 · 4H2O, BA) as raw materials, the LDHs complex (BA-LDHs) of B5O8- intercalation was prepared by one-step hydrothermal method. The BA-LDHs samples were characterized by a X-ray powder diffractometer (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and the Brunauer-Emmett-Teller (BET) method. The results showed that B5O8- was successfully intercalated. Adsorption experimental results suggested that BA-LDHs possess a maximum adsorption capacity of 18.7, 57.5, 70.2, and 3.12 mg·g-1 for Cd(II), Cu(II), Cr(VI) and Methylene blue (MB) at Cs = 2 g·L-1, respectively. The adsorption experiment conforms to the Langmuir and Freundlich adsorption models, and the kinetic adsorption data are well fitted by the pseudo-second-order adsorption kinetic equation. The as-prepared BA-LDHs have potential application prospects in the removal of heavy metals and dyes in wastewater. More importantly, they also provide a strategy for preparing selective adsorbents.
摘要:
重金属和有机污染物在水体中普遍存在,对环境和人类造成极大的破坏。因此,迫切需要开发一种性能优良的吸附剂。阴离子交错层状双氢氧化物(LDHs)是一种可持续去除废水中重金属离子和染料的吸附剂。使用氯化铝,氯化锌和五硼酸铵四水合物(NH4B5O8·4H2O,BA)作为原材料,通过一步水热法制备了B5O8-插层的LDHs复合物(BA-LDHs)。用X射线粉末衍射仪(XRD)对BA-LDHs样品进行了表征,扫描电子显微镜(SEM),傅里叶变换红外光谱仪(FT-IR)和Brunauer-Emmett-Teller(BET)方法。结果表明,B5O8-插层成功。吸附实验结果表明,BA-LDHs对Cd(II)的最大吸附容量为18.7、57.5、70.2和3.12mg·g-1,Cu(II),Cr(VI)和亚甲基蓝(MB)分别为Cs=2g·L-1。吸附实验符合Langmuir和Freundlich吸附模型,动力学吸附数据通过拟二级吸附动力学方程得到很好的拟合。所制备的BA-LDHs在去除废水中的重金属和染料方面具有潜在的应用前景。更重要的是,它们还提供了制备选择性吸附剂的策略。