Insights into the adsorption mechanism of carbon cellulose fiber loaded globular flowers bimetallic layered double hydroxide for efficiency pollutant removal

Abstract

An environmentally-friendly CuAl-layered double hydroxide (LDH)/carbon cellulose fiber (CuAl-LDH/CCF) synthesized via one-pot precipitation and green hydrothermal method. The prepared cellulose-based immobilized carrier was prepared using sisal as the natural precursor and attempted to fabricate hierarchical structure materials. The XRD, BET, FTIR, RS and EDS techniques were employed for characterization of the as-prepared materials and elucidation of their adsorption mechanism. The characterization results indicated that the LDHs nanosheets with the sizes of about 5–10 μm were successfully anchored on the surface and dispersed into the walls of natural carbon fiber matrix, and the resultant nanocomposites have a uniform mesostructure with a high specific surface area and large pore volume. The obtained CuAl-LDH/CCF sample exhibited the better adsorption performance of phosphorus, in comparison with pure LDH and Cu/Al-LDH, the high adsorption capacity of the as-prepared adsorbent can be attributed to the synergetic effect of the CuAl-LDH nanosheets and carbon cellulose fiber. The adsorption isotherm and kinetic studies show that adsorption of phosphorus on the as-prepared materials were better described by the Langmuir equilibrium model and the pseudo-second order kinetic model. The maximum adsorption capacity of the CuAl-LDH/CCF was determined to be 105.26 mg/g, and the adsorption process was spontaneous and exothermic. The results indicated that phosphorus ions were adsorbed mainly mechanism including electrostatic attraction, ligand exchange and ion exchange. The CuAl-LDH/CCF still has >85% of the phosphorus removal percentage after fifth adsorption-desorption recycles of reuse. The hierarchical CuAl-LDH/CCF can be considered as a potentially adsorbent for applied in waste water treatment.