This research investigates the feasibility of a novel approach involving a fixed-bed column system with recirculation for copper ion removal from wastewater. Adsorption kinetics of zeolites were examined using a well-established batch system and compared to a fixed-bed column recirculation system, a configuration for which only limited investigations exist. Zeolite was chosen as the adsorbent due to its efficiency, affordability, availability, and eco-friendliness. The recirculation system was designed for comparative analysis with the batch system, assessing adsorption kinetics, reaction rate constants, and orders under various initial copper concentrations (100, 300, and 500 mg dm−3). Zeolite particles (2–3 mm) were used in the recirculation system, while finer particles (63 µm) were employed in the batch system. Experimental conditions, such as adsorbent dosage and initial pH, were kept constant to ensure the comparability of the two systems. Copper concentrations in the filtrate were measured using an atomic absorption spectrophotometer (AAS). Three experimental kinetic models were developed to describe the adsorption processes. The results indicate that the adsorption processes correlate best with Ho’s pseudo-second-order (PSO) kinetic model. Results revealed superior removal efficiency (9.77 mg g−1) with the recirculation system using coarser particles compared to the batch system (7.82 mg g−1) with finer particles, highlighting enhanced adsorption driving forces in the recirculation configuration. The fixed-bed column system with recirculation demonstrates superior efficiency over batch systems and reduced processing time compared to conventional fixed-bed configurations.

中文翻译：

---

沸石固定床系统通过再循环增强，以改善废水中铜离子的去除：动力学模型和与批处理系统的比较

本研究调查了一种涉及固定床塔系统的新方法的可行性，该方法具有再循环功能，用于从废水中去除铜离子。使用成熟的批处理系统检查沸石的吸附动力学，并与固定床塔再循环系统进行比较，后者的配置仅存在有限的研究。选择沸石作为吸附剂是因为它的效率、可负担性、可用性和环保性。再循环系统设计用于与间歇系统进行比较分析，评估各种初始铜浓度（100、300 和 500 mg dm-3）下的吸附动力学、反应速率常数和顺序。再循环系统使用沸石颗粒 （2-3 mm），而批处理系统使用更细的颗粒 （63 μm）。吸附剂用量和初始 pH 值等实验条件保持不变，以确保两个系统的可比性。使用原子吸收分光光度计 （AAS） 测量滤液中的铜浓度。开发了三个实验动力学模型来描述吸附过程。结果表明，吸附过程与 Ho 的准二级 （PSO） 动力学模型最相关。结果显示，与使用较细颗粒的批处理系统 （7.82 mg g-1） 相比，使用较粗颗粒的再循环系统具有更高的去除效率 （9.77 mg g-1），突出了再循环配置中增强的吸附驱动力。与传统的固定柱配置相比，具有再循环功能的固定柱系统表现出优于批处理系统的效率，并缩短了处理时间。