2,4-二硝基苯酚(DNP)被列为优先污染物;因此,DNP污染的废水必须在排放到接收资源之前进行处理。在本研究中,采用混合超声辅助GO-Fe3O4系统对DNP溶液进行净化。超声辐照使吸附物的传质得到改善,Fe3O4使GO在外部磁场下从液相中分离。用SEM对合成的GO-Fe3O4复合材料进行了表征,TEM,XRD,FTIR,BET和VSM。基于响应面方法的中心复合材料设计(RSM-CCD)用于估算和优化DNP去除百分比的各种变量。在最佳条件下(pH:4.45,吸附剂剂量:0.178g/L,超声频率:40.02kHz,DNP浓度:50.10mg/L,超声系统的最大吸附容量为425.58mg/g,高于简单系统309.40mg/g,表明超声波与吸附过程之间协同作用的重要性。超声辅助吸附体系与Langmuir等温线有较好的一致性(R2>0.997),而搅拌系统的结果更符合Freundlich模型(R2>0.991)。实验结果表明,在超声和无声系统下,实验数据和速率常数拟合良好的伪二阶动力学模型分别为0.000148min-1和0.000002min-1,分别。超声下的解吸速率更有利,并且在连续第10次循环后,两个系统中吸附剂的重复使用减少了约22%。热力学计算也证实了两个系统的吸热性和自发性。静电吸引,氢键,π-π相互作用在DNP在MGO上的吸附中起着关键作用。总之,这项研究的结果为超声辅助GO-Fe3O4系统的实际应用提供了有价值的信息。
2,4-Dinitrophenol (DNP) was listed as a priority pollutant; accordingly, DNP-contaminated effluent must be treated before discharging to the receiving resources. In the present study, the hybrid ultrasound-assisted GO-Fe3O4 system was employed to decontaminate DNP solution. Ultrasound irradiation makes the mass transfer of adsorbate improved and Fe3O4 enables GO separation from liquid phase under external magnetic field. The as-synthesized GO-Fe3O4 composite was characterized by SEM, TEM, XRD, FTIR, BET and VSM. A response surface methodology based central composite design (RSM-CCD) was used to estimate and optimize of various variables on DNP removal percentage. Under optimal conditions (pH: 4.45, adsorbent dose: 0.178 g/L, ultrasound frequency: 40.02 kHz and DNP concentration: 50.10 mg/L, maximum adsorption capacity was calculated to be 425.58 mg/g for the ultrasound system, higher than the simple system 309.40 mg/g, indicating the importance of synergistic effect between the ultrasound waves and the adsorption process. The ultrasound-assisted adsorption system showed the better agreement with the Langmuir isotherm (R2 > 0.997), while the results of the stirring system were more consistent with the Freundlich model (R2 > 0.991). The experimental results indicated that the pseudo-second-order kinetic model well fitted by experiment data and rate constant was calculated to be 0.000148 min-1 and 0.000002 min-1 under ultrasound and silent systems, respectively. The rate of desorption under ultrasound was more favorable and reuse of the adsorbent in both systems after 10th consecutive cycles reduced by about 22%. Thermodynamic calculations also confirmed the endothermicity and spontaneity of both systems. Electrostatic attraction, hydrogen bonding, and π -π interactions played key roles during the adsorption of DNP onto the MGO. In conclusion, the outcomes of this study provide valuable information of the ultrasound-assisted GO-Fe3O4 system for practical applications.