Fabrication of MIL-53(Al) based composites from biomass activated carbon (AC) for efficient p-nitrophenol adsorption from aqueous solution

Background The aim of this study was to develop a class of novel MIL-53(Al) based composite with high phenolic compound adsorption capacity to treat highly toxic phenolic wastewater. Method MIL-53(Al)@AC-x composites with different AC loading ( x ) were constructed by combining MIL-53(Al) with cheap biomass AC derived from cheap rice husk. The adsorbents were characterized by various methods. Significant findings The results showed that the surface area and pore volume of all MIL-53(Al)@AC-x composites increased remarkably, which are much higher than those of pristine AC and MIL-53(Al). The p-nitrophenol adsorption rate of MIL-53(Al)@AC-10 was higher than pristine MIL-53(Al) by 36%. The adsorption performance decreased in the order of MIL-53(Al)@AC-10 > MIL-53(Al)@AC-15 > MIL-53(Al)@AC-5 > MIL-53(Al). The maximum adsorption capacity for p-nitrophenol of MIL-53(Al)@AC-10 reached 250 mg.g −1 , which are higher than the data reported in most literature. The fabrication of AC into MIL-53(Al) is a promising method to obtain a composite with high adsorption capacity and stability. The adsorption kinetics and isotherms fitted well with pseudo-second-order model and Langmiur model. The adsorption is mainly through the π-π and hydrogen bond interactions, and hydrophobic effect.