School of Chemical Engineering and Technology, Hebei University of Technology, No.8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
School of Chemical Engineering and Technology, Hebei University of Technology, No.8 Guangrong Road, Dingzi Gu, Hongqiao District, Tianjin, 300130, China.
J Environ Manage. 2020 May 15;262:110260. doi: 10.1016/j.jenvman.2020.110260. Epub 2020 Feb 22.
In this study, multi-walled carbon nanotubes (MWCNTs) had been used to strengthen the removal of acid orange 7 (AO7) from the dyestuff wastewater by using foam fractionation. First, the surface modification of MWCNTs was performed by introducing hypochlorite groups (-OCl). The modified MWCNTs were characterized by using SEM, XRD, FTIR and Raman spectroscopy. Subsequently, the potential of modified MWCNTs as a novel collector for AO7 adsorption was examined. The adsorption conditions of modified MWCNTs towards AO7 were optimized by using response surface methodology (RSM) with a central composite design (CCD). The adsorption capacity of modified MWCNTs towards AO7 could reach 47.72 ± 0.79 mg·g under the optimum conditions. The kinetics and the equilibrium adsorption data were analyzed by using different kinetic and isotherm models. According to the regression results, adsorption kinetics data were well described by pseudo-second order model, whereas adsorption isotherm data were best represented by Langmuir isotherm model. Finally, foam fractionation was performed with a batch mode. Under the suitable conditions of loading liquid volume 300 mL, modified MWCNTs dosage 180 mg, cetyltrimethylammonium bromide (CTAB) concentration 50 mg·L, AO7 concentration 30 mg·L, pore diameter of gas distributor 0.125 mm and air flow rate 100 mL·min, the removal percentage and enrichment ratio of AO7 were 91.23% and 6.17, respectively. The decolourization ratio of solution after foam fractionation was found to be 98.66%.
在这项研究中，使用多壁碳纳米管 (MWCNTs) 通过泡沫浮选来增强对酸性橙 7 (AO7) 的去除。首先，通过引入次氯酸盐基团 (-OCl) 对 MWCNTs 进行表面改性。通过 SEM、XRD、FTIR 和拉曼光谱对改性后的 MWCNTs 进行了表征。随后，研究了改性 MWCNTs 作为新型 AO7 吸附剂的潜力。通过中心复合设计 (CCD) 响应面法优化了改性 MWCNTs 对 AO7 的吸附条件。在最佳条件下，改性 MWCNTs 对 AO7 的吸附容量可达到 47.72 ± 0.79 mg·g。通过不同的动力学和等温吸附模型分析了吸附动力学和平衡吸附数据。根据回归结果，吸附动力学数据很好地符合拟二级动力学模型，而吸附等温线数据则最好用 Langmuir 等温线模型来描述。最后，采用分批模式进行泡沫浮选。在适宜的条件下，装载液体体积为 300 mL，改性 MWCNTs 用量为 180 mg，十六烷基三甲基溴化铵 (CTAB) 浓度为 50 mg·L，AO7 浓度为 30 mg·L，气体分布器孔径为 0.125 mm，空气流速为 100 mL·min，AO7 的去除率和浓缩比分别为 91.23%和 6.17。泡沫浮选后溶液的脱色率达到 98.66%。
