In this study, three effective adsorbents such as Padina sanctae cruces algae (PSC), activated carbon (AC), and bentonite clay were used to remove gas condensates from industrial wastewater generated in the fourth refinery of South Pars Gas Complex in Iran. Physical and surface properties of the adsorbents were characterized using Brunauer–Emmett–Teller (BET), field‐emission scanning electron microscope, Fourier transform‐infrared spectroscopy, and energy dispersive X‐ray spectroscopy (EDAX) analyses. Also, droplet size distribution analysis was used to determine the size distribution of gas condensate droplets in the emulsion and to evaluate the emulsion stability. According to the BET analysis, the specific surface area of AC, PSC, and bentonite were obtained as 900.93, 0.0463, and 40.70 m²/g, respectively. To check the effect of different parameters on the removal efficiency of gas condensates, the Box–Behnken design method was used. Moreover, the optimal conditions for the removal of gas condensates included pH 9, temperature of 65°C, contact time of 120 min, and an adsorbent dosage of 5 g/L. Under such optimal conditions, the adsorption efficiencies using AC, PSC, and bentonite were obtained as 98.90%, 96.35%, and 97.24%, respectively. Furthermore, the maximum adsorption capacities of 1250, 54.95, and 99.01 mg/g were achieved using AC, PSC, and bentonite, respectively, in which AC showed the highest adsorption capacity ever achieved for the removal of gas condensate from wastewater. Besides, the thermodynamic study indicated that the sorption process was exothermic and spontaneous.

中文翻译：

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使用低成本吸附剂去除工业废水中的冷凝水：Box–Behnken设计方法的优化

在这项研究中，使用了三种有效的吸附剂，例如Padina sanctae ces藻（PSC），活性炭（AC）和膨润土，以去除伊朗南帕尔斯煤气综合体第四炼油厂产生的工业废水中的气体冷凝物。吸附剂的物理和表面性质使用Brunauer-Emmett-Teller（BET），场发射扫描电子显微镜，傅里叶变换红外光谱和能量色散X射线光谱（EDAX）分析进行了表征。另外，液滴尺寸分布分析用于确定乳液中气体冷凝液滴的尺寸分布并评估乳液稳定性。根据BET分析，AC，PSC的比表面积得到的膨润土为900.93m ² / g，膨润土为0.0463m ² / g。为了检查不同参数对气体冷凝物去除效率的影响，使用了Box–Behnken设计方法。此外，去除气体冷凝物的最佳条件包括pH 9，温度65°C，接触时间120分钟和吸附剂剂量5 g / L。在这种最佳条件下，使用AC，PSC和膨润土的吸附效率分别为98.90％，96.35％和97.24％。此外，使用AC，PSC可实现1250、54.95和99.01 mg / g的最大吸附容量和膨润土，其中AC显示出从废水中去除气体冷凝物所获得的最高吸附能力。此外，热力学研究表明吸附过程是放热的和自发的。