The removal efficiency of two anionic dyes, namely direct red 81 (DR 81) and reactive blue 19 (RB 19), from aqueous solution was investigated through batch adsorption experiments by using magnetic graphene oxide coated with branched-polyethylenimine (PEI/MGO) nanocomposite as an adsorbent. The physicochemical properties of PEI/MGO were analyzed via FTIR, XRD, FE-SEM, EDS, VSM, TGA, and BET methods. The removal efficiency of dyes was evaluated as a function of various parameters (initial solution pH, adsorbent dosage, contact time, temperature, initial dye concentration, and ionic strength). The nonlinear form of fractal-like pseudo-second-order kinetic and Freundlich isotherm models described reasonably the adsorption mechanism. The maximum adsorption capacity of PEI/MGO for DR 81 and RB 19 at pH 3.0 and 328 K was calculated to be 284.3 and 269 mg g⁻¹, in the respective order that was much higher than that of MGO. The thermodynamic analysis revealed that the adsorption is a physisorption process with a spontaneous and endothermic characteristic. In addition, regeneration experiments demonstrated that the recyclability of PEI/MGO is encouraging. Finally, data from the preliminary application of 30 mg of PEI/MGO to remove DR 81 and RB 19 (40 mg L⁻¹) from 40 mL of spiked groundwater samples indicated greater than 99% and 95% recovery, respectively, with the contact time of 30 min at room temperature. According to the experimental results, the PEI/MGO is potentially capable of purifying anionic dyes-polluted water.

通过使用支化聚乙烯亚胺（PEI / MGO）纳米复合材料包覆的磁性氧化石墨烯，通过间歇吸附实验研究了两种阴离子染料从水溶液中的去除效果，分别是直接红81（DR 81）和活性蓝19（RB 19）。作为吸附剂。通过FTIR，XRD，FE-SEM，EDS，VSM，TGA和BET方法分析了PEI / MGO的理化性质。根据各种参数（初始溶液pH，吸附剂用量，接触时间，温度，初始染料浓度和离子强度）评估染料的去除效率。分形的拟二阶动力学和Freundlich等温线模型的非线性形式合理地描述了吸附机理。计算得出在pH 3.0和328 K下，PEI / MGO对DR 81和RB 19的最大吸附容量为284。^-1，其顺序远高于MGO的顺序。热力学分析表明，吸附是具有自发吸热特性的物理吸附过程。此外，再生实验表明，PEI / MGO的可回收性令人鼓舞。最后，初步应用30 mg PEI / MGO从40 mL加标地下水样品中去除DR 81和RB 19（40 mg L ^-1）的数据表明，接触后回收率分别高于99％和95％在室温下30分钟的时间。根据实验结果，PEI / MGO可能具有净化阴离子染料污染的水的能力。