p-Hydroxybenzoic acid is an emerging contaminant because it has multiple sources such as the hydrolysis of methylparaben, ethylparaben and propylparaben used widely as preservatives in food and drinks, and as well as from the agro-industrial wastewaters. In this study, the nano-ZIF-8@chitosan microspheres (ZIF-8@CSM) were fabricated via the combination of inverse emulsion method and in-situ growth method. The performance of ZIF-8@CSM for the adsorption of p-hydroxybenzoic acid from aqueous solution was studied. The adsorption kinetics showed that the adsorption rapidly reached the equilibrium about 30 s. The equilibrium data were well described by the Langmuir isothermal model and the estimated maximum adsorption capacity was 128.70 mg/g. The thermodynamics analysis indicated negative free energy, enthalpy, and entropy changes suggesting that the adsorption process was spontaneous and exothermic. ZIF-8@CSM is promising to be used as a good adsorption material to remove p-hydroxybenzoic acid rapidly from aqueous solutions.

对羟基苯甲酸是一种新兴的污染物，因为它有多种来源，如对羟基苯甲酸甲酯，对羟基苯甲酸乙酯和对羟基苯甲酸丙酯的水解，广泛用于食品和饮料以及农用工业废水中的防腐剂。本研究采用反相乳液法和原位生长法相结合制备了纳米ZIF-8 @壳聚糖微球（ZIF-8 @ CSM）。ZIF-8 @ CSM吸附p的性能研究了水溶液中的-羟基苯甲酸。吸附动力学表明，吸附在30 s左右迅速达到平衡。Langmuir等温模型很好地描述了平衡数据，估计的最大吸附容量为128.70 mg / g。热力学分析表明负的自由能，焓和熵的变化表明吸附过程是自发的并且放热的。ZIF-8 @ CSM有望被用作从水溶液中快速去除对羟基苯甲酸的良好吸附材料。