The adsorption of Reactive Red 33 dye from aqueous solution onto light expanded clay aggregate (LECA) in a batch mode, fixed‐bed reactor has been investigated. The adsorption studies were determined as a function of dye initial concentration, pH, flow rate, temperature, and adsorbent size using response surface methodology. The maximum amount of dye removal (85.11%) was obtained in the optimized conditions (pH = 2, C₀ = 20 mg/L, and T = 20°C; flow rate: 40 L/min and smaller size of LECA granules). Also, high‐frequency ultrasound waves have been applied for desorption process which improved the desorption efficiency by 81%. Equilibrium data are fitted well with Langmuir isotherm model and obeyed the Weber–Morris and external diffusion kinetic models. The exothermic nature and negative amount of Gibbs free energy change confirmed the spontaneous nature of this process. The maximum adsorption capacity, q_max, as estimated by Langmuir isotherm model was 1.363 mg/g.

中文翻译：

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操作条件对固定床反应器中连续流动去除染料流出物的影响，使用轻质膨胀粘土作为绿色吸附剂，超声辅助解吸，固定床反应器

研究了间歇式固定床反应器中活性红33染料从水溶液到轻质膨胀黏土骨料（LECA）上的吸附。使用响应表面方法将吸附研究确定为染料初始浓度，pH，流速，温度和吸附剂尺寸的函数。在优化的条件下（pH = 2，C ₀ = 20 mg / L和T），获得了最大的染料去除量（85.11％）。= 20°C；流速：40 L / min和较小的LECA颗粒尺寸）。此外，高频超声波已应用于解吸过程，使解吸效率提高了81％。平衡数据与Langmuir等温线模型非常吻合，服从Weber-Morris和外部扩散动力学模型。吉布斯自由能变化的放热性质和负量证实了该过程的自发性质。由Langmuir等温模型估算的最大吸附容量q _max为1.363 mg / g。