Shi Yawei, Liu Guozhu, Wang Liang, Zhang Hongwei
State Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental Science and Engineering, Tianjin Polytechnic University Tianjin 300387 China
School of Chemical Engineering and Technology, Tianjin University Tianjin 300072 China.
RSC Adv. 2019 Jun 5;9(31):17841-17851. doi: 10.1039/c9ra02610j. eCollection 2019 Jun 4.
A series of activated carbons with surface areas of 925-1929 m g were synthesized by hydrothermal impregnation of sucrose with HPO and subsequent calcination at 500-900 °C. The prepared various types of activated carbons were utilized for the removal of sulfamethoxazole (SMX) from its solution by adsorption, and the effects of contact time, adsorbent dosage, initial concentration, adsorption temperature and pH on SMX adsorption were studied. The pseudo-second-order and the intra-particle diffusion model were used to analyze the adsorption kinetic data. The adsorption isotherm studies showed that the activated carbon prepared at 900 °C (C-900) showed the highest Langmuir maximum adsorption capacity of 808.7 mg g among them, much higher than that of C-500 (274.0 mg g). Adsorption thermodynamic results showed that the adsorption of SMX was a spontaneous exothermic process, with a standard enthalpy change of -6.59 kJ mol and a standard entropy change of 47.7 J mol K. It was deduced that hydrophobic, electron donor-acceptor and electrostatic interactions were involved in the adsorption mechanism. Finally, regeneration experiments showed that more than 90% of the adsorption capacity could be recovered after four cycles through ethanol washing. Considering the remarkable and regenerable adsorption ability as well as the economic and environmental merits, these activated carbons are considered as promising candidates for potential practical applications in adsorptive removal of SMX.
通过用H₃PO₄对蔗糖进行水热浸渍并随后在500 - 900℃下煅烧，合成了一系列比表面积为925 - 1929 m²/g的活性炭。将制备的各种类型的活性炭用于通过吸附从其溶液中去除磺胺甲恶唑（SMX），并研究了接触时间、吸附剂用量、初始浓度、吸附温度和pH对SMX吸附的影响。采用准二级动力学模型和颗粒内扩散模型分析吸附动力学数据。吸附等温线研究表明，在900℃制备的活性炭（C - 900）在其中表现出最高的朗缪尔最大吸附容量，为808.7 mg/g，远高于C - 500（274.0 mg/g）。吸附热力学结果表明，SMX的吸附是一个自发的放热过程，标准焓变为 - 6.59 kJ/mol，标准熵变为47.7 J/(mol·K)。推断吸附机理涉及疏水作用、电子供体 - 受体作用和静电相互作用。最后，再生实验表明，通过乙醇洗涤四个循环后，可回收超过90%的吸附容量。考虑到其显著且可再生的吸附能力以及经济和环境优势，这些活性炭被认为是吸附去除SMX潜在实际应用的有前途的候选材料。
